Who are the owners of the various bulb code systems? What are their specs?

scootley

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Hi,
This is sort of an academic question but one of interest to me.

There seem to be at least two commonly used bulb code systems (perhaps my observations are specific to the USA).

Take this thread/post as an example:
2825 is not an ANSI number, it is Osram's number for a W5W bulb. W5W, in turn, is closely approximate to 168 -- they both produce about 50 lumens


  • First there are what people tend to call the "ECE" codes, standardized by a body of the UN within the UNECE. They all seem to start with a letter and have well documented and publicly available specifications for each code. W5W in this example. I understand that W5W does not necessarily correspond to exactly one physical product but a category or family with some variability in the actual bulbs that meet that spec. For example they could be between 40 and 60 lumens.
  • Then there are these fully numeric codes such as 2825. As @-Virgil- basically says above, I guess this is an Osram/Sylvania number. And apparently (one of?) their implementation(s) of W5W.
  • What about 168? Is that a Philips number? Or something else?


But my real questions are these:

  1. How many commonly used numbering systems are there and what are they called (or what should we call them)? Maybe this is similar to asking who are the major manufacturers of bulbs (Osram/Sylvania, Phillips, anyone else?)
  2. For each system (other than ECE):
    1. Who is the standards body or company (or other entity) that either came up with that system or is in control of it? Note: I understand that some of these code systems are basically de-facto industry standards but there is probably one entity that at least came up with them if not controls them today.
    2. Where can I find the specification that defines each bulb code within that system (e.g. shape, base, wattage, lumens, and stuff like that)? I know the answer may simply be to look at the spec sheet or web page for each individual bulb from each manufacturer but am looking for something easier to browse all at once.
  3. Does anyone know of a master table/cross-reference that includes all automotive bulbs and shows the ECE code along with codes from all other common systems and links them so that people can easily convert between systems?

I did find this fantastic post which does help quite a bit.

Thanks much!
 

-Virgil-

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Welcome to the board!

There seem to be at least two commonly used bulb code systems (perhaps my observations are specific to the USA).

In Europe and much of the rest of the world, there's one official system (the designations prescribed in the UN Regulations, formerly called the "ECE Regulations") universally used. Those designations are more or less a subset of designations promulgated by the IEC, that is International Electrotechnical Commission. Not all IEC types are adopted in the UN Regulations. Some of the UN bulb designations have replaced older designations. For example, W5W used to be W10/5, T4W used to be T8/4, P21W used to be P25-1, and P21/5W used to be P25-2.

There are many different bulb designation systems in use in North America. There are designations put forth by NHTSA, by ANSI, and by industry.

Industry designation examples include 168, 194, 1157, 3157, 7440.

Some bulbs have more than one designation. For example:
HB1 (NHTSA designation), 9004 (ANSI designation)
HB3 (NHTSA designation, also adopted in the UN regs), 9005 (ANSI designation)

Some bulbs have only an ANSI designation. Not a whole lot of examples, but one that comes to mind is the 9500 (an HID headlamp light source made by Sylvania, pre-Osram, and used only in the Lincoln Mark 8 of the 1990s)

In Japan, the situation is mixed: they use a lot of UN-designated bulbs, and have for many years, even before they began formally applying UN Regulations on lighting in the early 2000s. But they also have a fair number of bulbs with Japanese industry designations. Some of those are IEC designations, and some, who knows where they came up with them. Examples: D6, IH01.

I understand that W5W does not necessarily correspond to exactly one physical product but a category or family with some variability in the actual bulbs that meet that spec. For example they could be between 40 and 60 lumens.

It's not quite clear to me whether you have quite snapped to what this means. W5W is a category (type), but that doesn't mean it's a family. There's no such thing as "No, this is a 40-lumen W5W, I need a 60-lumen W5W". A W5W has an output spec of 50 lumens, +/- 20%. So yes, that's 40 to 60 lumens, but a sample that produces 40 lumens and a sample that produces 60 lumens are legally equivalent; they are both W5W bulbs (assuming they meet all the other specs). That doesn't preclude a maker from producing different varieties of W5W (standard, long life, heavy duty, etc).

Then there are these fully numeric codes such as 2825. As @-Virgil- basically says above, I guess this is an Osram/Sylvania number.

Right. Everywhere in the world, every maker has its own item number for whatever kind of bulb. It's common in America (but not universal) for the industry number to be the order number/part number, sometimes with additional characters denoting packaging variants, like you might see "194NABP2" meaning a blister pack of two 194NA bulbs. Speaking of that, there's no formal difference between "A" and "NA". It used to commonly denote the difference between bulbs painted amber (the ones that looked like they got hit with overspray when a taxicab or school bus was being painted) like "1157A" and bulbs made of amber glass, so-called natural amber, like "1157NA". But the NA bulbs had much better colorfastness (paint was easy to chip/scrape off, and lower grades of it burned off) so they were hugely dominant until concerns arose with cadmium in the glass, which pushed a return to coated bulbs, only this time with transparent amber coatings, and now Sylvania (for sure, and maybe others) use "A" for coated bulbs and "NA" for amber glass...except when they don't.

So how do you order, say, a standard 12-volt P21/5W bulb? Well, that's a Philips 12499, or an Osram 7528, or a Narva 17916, or a Wagner 17916, or a Lucas 380, etc.

What's a Philips 12-volt H4? Depends which one! A standard one is a 12342. A heavy-duty one is 12342/99. A French-spec one (yellow glass cover) was 12342/86. A +30 is 12342PR. A +50 is 12342HV. A +80 is 12342XP. A +130 is 12342XV. A blue "Crystal Vision" is 12342CV.

It works the same way in America; including the OEM and aftermarket product offerings, Osram-Sylvania offers about 10 different 9005 bulbs, differentiated by different letters after the "9005".

There are also types with numbers of unclear origin. 3496 and 3497 are examples, along with 3652 (and probably more the longer I sit here and think about it).

There are also "phantom" type numbers that have been whipped up into existence, out of thin air. For example, the "9008" pseudo-designation for what everybody in the world calls an H13 bulb. That "9008" looks like an ANSI designation, but there is no such ANSI designation. It doesn't exist. Some yahoo somewhere went "Well, huh, this bulb came after the 9007, so I guess it's a 9008!" and printed it in a manual somewhere, which caused people to go looking for a "9008" bulb, which caused makers to have to put "9008" alongside the real (H13) designation on the packaging. There's no end of noise that gets added to the designation systems by the less reputable ends of the aftermarket gutter, where you can learn all kinds of untrue baloney like "Well, there are two completely different kinds of H16 bulb, they look totally different and they don't interchange but they're both called H16".

And there's one guy in America who hand-gathers the bulb application info for most of the makers' application guides (or at least that used to be the case; I don't know if he's still at it), and he did it in a very low-tech manner: he went to car dealers and asked to see the bulbs for (or in) each kind of lamp in each model of car. When he was faced with a type he hadn't seen, he just faked it. That's how the 7440 bulb got its not-real alternate designation of "992", and it's how the PSX24W bulb got its fake designations "5202" and "2504". Those were batch codes and/or date codes on the unfamiliar bulbs, and this one Joe Schmoe elevated them into "designations" by putting them in application catalogs.

What about 168? Is that a Philips number?

It's a US industry number -- many, many years old.

Where can I find the specification that defines each bulb code within that system (e.g. shape, base, wattage, lumens, and stuff like that)? I know the answer may simply be to look at the spec sheet or web page for each individual bulb from each manufacturer but am looking for something easier to browse all at once

Well, UN Regulations 37 (filament), 99 (HID) and 128 (LED) cover all the UN types and are available as free downloads.

SAE J2560 covers halogen bulbs and contains a nice table giving the various designations for bulbs that have multiple designations (did you know H3 has an ANSI designation? It's 9200. Nobody ever calls an H3 bulb a 9200) as well as the specs for each type.

SAE J573 covers signal and marking bulbs, and has a similar table.
(I notice SAE has put their prices up again...jeez!)

The Japanese specs are harder to get a hold of. The document is JIS C7506, and it comes in 3 parts. The part with the specs is Part 1. Mostly it's just a copy of the UN Regs, but with some additional data sheets for Japan-specific types you aren't very likely to run into.

Beyond that, it's hunt and peck. Donsbulbs is (sadly) dead and gone, which makes life harder when you're trying to find info like this. Dan Stern has (or used to have) a nice spreadsheet of the plastic wedge bulbs...everybody knows about 3157 and the other common ones, but there are a whole lot more than that, some of which are obscure and interesting.

Does anyone know of a master table/cross-reference that includes all automotive bulbs and shows the ECE code along with codes from all other common systems and links them so that people can easily convert between systems?

That Volvo post you found probably comes closest, but keep in mind there really isn't a "conversion" like you seem to want. 194 and W3W are generally cross-compatible, but they are not the same bulb. They put out about the same amount of light, and they fit in each other's sockets, but they aren't built to the same specs, they don't have the same filament type, and they don't have the same base -- the 194 has a W2.1x9.2d while the W3W has a W2.1x9.5d. Similar goes for 168 vs. W5W. And 1156 vs. P21W, 1157 vs. P21/5W, 1893 vs. T4W, 67 vs. R10W, etc. And things get more complicated, in more detail, if we talk about the significant optical differences between HB2/9003 vs. H4. Fit and function cross-compatible, at least at the level most people care about and can see, but technically-legally-optically not the same bulb.

And speaking of different bases for very similar bulbs: even when the base (cap)/socket is the same, its designation can differ.

IEC (+UN, +Japan) says "BA15s", US says "SC Bayonet".
IEC says "BA15d", US says "DC Bayonet".
IEC says "BAY15d", US says "DC Bayonet Index".
IEC says "BA9s", US says "SC Mini Bayonet".
and so on, where "SC" = "single contact" and "DC" = "double contact".

The IEC cap/socket designations are pretty easy to decode at least in rough:
First character = general type. "BA" for bayonet, "P" for prefocus, "E" for Edison (screw), "W" for wedge, and a few others. Optionally followed by a letter signifying an indexing/keying variant within a family.

Second one or two characters = cap diameter in millimeters, except in case of Wedge bases where you have two sets of numbers defining the width and height of the base wedge.

Next character = number of contacts, "s" for single, "d" for double, "t" for triple, "q" for quadruple.

Optional suffix number for specifying a secondary diameter

BA15s: Bayonet base, 15mm diameter, single contact.
(variants: BAU15s and BAZ15s with index pins in different locations to prevent interchangeability of different-color bulbs)

BAY15d: Bayonet base with indexing/keying feature, 15mm diameter, double contact.

W3.1x16q: Wedge base, 3.1 x 16 mm, four contacts.

E26: 26mm Edison screw base, the common American household screw-type light bulb

E27: 27mm Edison screw base, the common European household screw-type light bulb

P43t-38: Prefocus, 43mm diameter, three contacts, with a 38mm diameter elsewhere on the base
(variants: PU435, PZ43t...)

PK22s: Prefocus, keyed/indexed, 22mm diameter, single contact

P20d: Prefocus, 20mm diameter, double contact (HB3/9005 bulb)
PX20d: Prefocus, key/index variant, 20mm diameter, double contact (HIR1/9011 bulb)
PZ20d: Prefocus, key/index variant, 20mm diameter, double contact (H12/9055 bulb)

P29t: Prefocus, 29mm diameter, three contacts (HB1/9004 bulb)
PX29t: Prefocus, index/key variant, 29mm diameter, 3 contacts (HB5/9007 bulb)

And so on.
 
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scootley

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Wow Virgil thanks what an epic awesome reply. Took a while and several reads to absorb since I am new to the industry.

I do just want to add some focus to my initial question, because I wrote it from a perspective that I didn't mention:
Like I said originally, definitely an academic interest but it is also through the lens of buying replacement bulbs for vehicles. In other words, my primary interest is in the numbering systems for bulbs that would actually appear on a retail package or online listing to identify the bulb, like this:
mTNT9By

mTNT9By

image.png


Here's my attempt to summarize for bulbs people might see sold for the US market:
#Numbering systemWho's in controlDetail on bulbsNotes/Questions
1UN/ECEUNECEUN Regulations 37 (filament), 99 (HID) and 128 (LED)Some are derived from IEC 60061
2NHTSANHTSAI guess in NHTSA-1998-3397 (very difficult to easily browse summary-level info)Covers headlamps only?
3ANSI/SAESAENot free: SAE J2560 and SAE J573Are ANSI and SAE the same?
4Osram part numbersOsram/SylvaniaOne version here
5Philips part numbersPhilipsOne version here

Are there other bulb manufacturers that are really big in the retail replacement bulb market that I should list?
We can add on for other countries later after I make sure I have the US stuff reasonably correct.

Also for a cross-reference, I did find these as well:

  • This Bosch version has tables that cross-reference to other makers
  • This one from CEC
  • The Philips catalog has a cross-reference on pages 238-239 (using the page numbers written on the bottom of each page)

But I have quite a few questions after reading your post:
  1. Is ANSI numbering the same as SAE numbering? I see in SAE J573 a table that lists bulbs and the first/identifying column is titled "ANSI number", so I assume that ANSI and SAE use a single set of numbers and maybe SAE comes up with them and submits them to ANSI to make them official ANSI standards?
  2. When you refer to "Industry" as a source of numbering, you just mean individual manufacturers of bulbs like Osram and Philips, right? Or are you also including some other type of professional/trade organization(s) that span the industry and represent it as a whole (other than those listed in my table above)?
  3. It's not quite clear to me whether you have quite snapped to what this means. W5W is a category (type), but that doesn't mean it's a family. There's no such thing as "No, this is a 40-lumen W5W, I need a 60-lumen W5W". A W5W has an output spec of 50 lumens, +/- 20%. So yes, that's 40 to 60 lumens, but a sample that produces 40 lumens and a sample that produces 60 lumens are legally equivalent; they are both W5W bulbs (assuming they meet all the other specs). That doesn't preclude a maker from producing different varieties of W5W (standard, long life, heavy duty, etc).
    Thanks that is helpful. I didn't have an assumption either way.
  4. And there's one guy in America who hand-gathers the bulb application info for most of the makers' application guides ... and this one Joe Schmoe elevated them into "designations" by putting them in application catalogs.
    What are "application guides" and "application catalogs"?
  5. [168 is] a US industry number -- many, many years old.
    What do you mean by that? That it was conceived of by some manufacturer? Maybe originally but now I do see it in SAE J573
  6. 194 and W3W are generally cross-compatible, but they are not the same bulb. They put out about the same amount of light, and they fit in each other's sockets, but they aren't built to the same specs, they don't have the same filament type, and they don't have the same base ... Fit and function cross-compatible, at least at the level most people care about and can see, but technically-legally-optically not the same bulb
    Thanks that is good detail to know although I do think that for my dream of a cross-reference between numbering systems for the main purpose of helping people find compatible replacement bulbs, the general cross-compatibility and fit and function are enough. Going beyond that feels too detailed for the top-level cross-reference.
  7. IEC (+UN, +Japan) says "BA15s", US says "SC Bayonet".
    What entity in the US is in control of terms like "SC Bayonet" ? Or is it just de-facto (meaning that it would largely be the collective of bulb makers that controls such a term in an unofficial way)




 

-Virgil-

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Wow Virgil thanks what an epic awesome reply. Took a while and several reads to absorb since I am new to the industry.

Glad to help. Could I ask you to please cut back on the amount of formatting markup you put in your posts? It is not necessary or helpful to use markup code to create numbered lists of questions, change the fonts, etc, and it makes it harder to respond neatly.

Like I said originally, definitely an academic interest but it is also through the lens of buying replacement bulbs for vehicles.

OK, well, the best way to get the best info on the best bulbs for any particular application is to ask those questions directly: "What's the best bulb for the front turn signal on a [year] [make] [model]?" type of thing.

In other words, my primary interest is in the numbering systems for bulbs that would actually appear on a retail package or online listing

Aside from academic interest there's not much to be gained by spending time on this. It's not really reliable or useful for telling anything aside from what numbers various makers print on their packages and in their catalogs. The example picture you posted is a good example of why: that package doesn't contain a 2825, a 194 or a 168 bulb. It contains an LED that will fit in place of those bulbs, but doesn't work the same as any of them (different amounts of light, different colors of light, and the LED won't necessarily work in place of the incandescent bulb).

Docket 3397 covers replaceable light sources eligible for use in headlamps in the USA, yes. It does not cover any other vehicle bulbs, which are not directly regulated.

Are ANSI and SAE the same?

No. ANSI is the American National Standards Institute. SAE is the Society of Automotive Engineers. They are totally separate entities.

Are there other bulb manufacturers that are really big in the retail replacement bulb market

Wagner, Eiko, CEC...

that I should list?

Why?

We can add on for other countries later

Why?

Is ANSI numbering the same as SAE numbering?

There is no SAE numbering system for bulbs. Most of the American bulb numbers (53, 57, 158, 168, 194, 1156, 3157, etc) are ANSI numbers.

I assume that maybe SAE comes up with them and submits them to ANSI to make them official ANSI standards?

Why would you assume this?

When you refer to "Industry" as a source of numbering, you just mean individual manufacturers of bulbs like Osram and Philips, right?

Well, there's always going to be a bulb company involved, because bulb companies are the ones that make bulbs. There might also be a car company or a lamp company involved. Sometimes it's the result of one engineer's whimsy. For example, there used to be a very high output turn signal bulb with the W2.5x16d ("plastic wedge") cap. It looked just like a 3156, but with higher wattage and output. It was used only in one vehicle, for only two production years. Its designation was 3454NAK. The 3000-series is easy enough, that's same as 3156, 3057, 3157. The NA is for Natural Amber. The K is for Krypton. The 454? That's because the lead engineer on the bulb company team that developed it for the automaker was a fan of big-block Chevrolet V8 engines, such as the iconic 454.

What are "application guides" and "application catalogs"?

That's what you go look in when you want to know what kind of bulb goes in a particular lamp on a particular car.

Thanks that is good detail to know although I do think that for my dream of a cross-reference between numbering systems for the main purpose of helping people find compatible replacement bulbs

I don't really see the need. People find compatible bulbs every day without difficulty. What problem are you trying to solve?

What entity in the US is in control of terms like "SC Bayonet"?

I don't think an entity could be named in response to this question. It might be an ANSI term. Whether it originated with ANSI is at this point a "Who knows?" question, because it's been in use for a very long time.
 
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Alaric Darconville

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What entity in the US is in control of terms like "SC Bayonet" ?
It may have developed to be more descriptive or to help contextually identify a bulb as being a single contact bayonet-style bulb. There's the BA15s "BAyonet single contact" and the a BA15d, which is a "BAyonet double contact" bulb). The 15 refers to the 15mm base diameter, and you insert it in the socket and give it a twist, much like fixing a bayonet to a rifle. Nobody's "controlling" it, it's just part of the lexicon/jargon. Seems to me that phrase has been around a long time, to me it evokes mid '60s issues of "Popular Science" magazine.
 

scootley

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Your above comments are all kind of along the same theme so I will reply in aggregate. I kind of already explained my reasoning but I can elaborate. I want there to be an open (free, easy to access, not in a PDF) quick and easy cross reference guide on the internet in tabular form that lists all (or most) automotive bulbs as rows and has columns that cross reference the identifiers of those bulbs between all commonly found numbering schemes. So pretty much all of my research and questions have been to that end. The Volvo forum post and various PDFs I cited earlier are close to what I want but the purpose of the research and questions is to fill the gap. I don't necessarily think this forum is the ideal place to house this cross-reference, but for the moment it seemed like the best place to research it.

So, I personally do not want to know any specific "What's the best bulb for the front turn signal on a 2025 Ford Model T?" But I do want people who have acquired an answer to that question using one bulb numbering scheme to use the cross-reference to see the other identifiers for that bulb.

The level of precision on that package image I posted that says 2825 also fits 168/194 is I think a perfectly acceptable level of cross-compatibility for my cross-reference because it is the same level that exists on packaging and online product listings. So the fact that that package doesn't contain a "bulb" (arguable) but an LED with different characteristics may be relevant to a buyer but it is not relevant to a quick cross-reference. It can be explained as a general topic of interest in a footnote. If the LED won't work in place of an incandescent in certain vehicles then that's definitely important but also would be a footnote that applies across all rows. I guess if there are unique/distinct true standard (ECE, NHTSA, ANSI) identifiers that distinguish an LED from a non-LED even if they are otherwise a physical/electrical match, then those can be distinct rows. Basically whatever granularity the standard bodies have should drive the row count as a general rule. Differences in vendor part numbers would not be enough.

Yes people to find compatible bulbs every day already, but from personal experience I would not describe the process as "without difficulty". Depending on individual product listings, packages, or propriety vendor searches like AutoZone, Osram's site, etc, is not enough for me because they are not comprehensive, not known to be verified, and not in the right format.

Scootley said:
I assume that maybe SAE comes up with them and submits them to ANSI to make them official ANSI standards?]
Why would you assume this?

Right I know they are separate entities, but I meant do they use the same numbering, which you answered (yes). I assumed that SAE came up with the numbers because I cannot find any ANSI standard that defines them. There are these elusive citations in SAE J573 to a "ANSI ANSLG Special Report SR25e - 2009 Assigned Miniature Lamp Codes" but I have searched in every way I possibly can to find that document (for the public, whether free or paid) and cannot find it online anywhere. Maybe it really is the ANSI standards document that defines the ANSI automotive bulb numbers used by SAE, but I have no proof of that yet. Maybe no one has ever thought to put it online. Do you know the right standards doc for this?

Docket 3397 covers replaceable light sources eligible for use in headlamps in the USA, yes. It does not cover any other vehicle bulbs, which are not directly regulated.
...
Wagner, Eiko, CEC
...
I don't think an entity could be named in response to this question. It might be an ANSI term. Whether it originated with ANSI is at this point a "Who knows?" question, because it's been in use for a very long time

Thanks for those answers!

The 454? That's because the lead engineer on the bulb company team that developed it for the automaker was a fan of big-block Chevrolet V8 engines, such as the iconic 454.

Amazing trivia!

That's what you go look in when you want to know what kind of bulb goes in a particular lamp on a particular car.

So they are car model-specific documents dedicated to bulb identification? Wow, where can I find them? (say for a Honda Civic) Or are they only available to service technicians/dealers?
 
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scootley

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Nobody's "controlling" it, it's just part of the lexicon/jargon. Seems to me that phrase has been around a long time, to me it evokes mid '60s issues of "Popular Science" magazine.

Thanks good to know. So it's being controlled nowadays perhaps by the collective alone (just like the set of words in the English language is controlled by the collective of speakers of it)
 

-Virgil-

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I want there to be an open (free, easy to access, not in a PDF) quick and easy cross reference guide on the internet in tabular form that lists all (or most) automotive bulbs as rows and has columns that cross reference the identifiers of those bulbs between all commonly found numbering schemes.

We have the internet now, so whoever wants to find out the order number or EAN or SKU is for any particular brand of any particular kind of bulb can easily do so. Most people don't need to know those things. If they learn that a Philips X-Treme Vision H13 (for example) is the best bulb for their headlamps, that right there is enough to allow them to find and buy the bulb. If they learn that a 3652 is the best bet for whatever they're trying to do, they can search for 3652 bulb plus whatever brand name they prefer and find a vendor. If they (i.e., you) really want to know all those order numbers for all those brands, you can use the internet, too, to get the various makers' catalogs. Your idea to amass a great big cross reference strikes me as a great deal of pointless work guaranteed to start fights and arguments, so probably here is the ideal place to get to work on it (there's even a special page just for the fights and arguments!)

I don't necessarily think this forum is the ideal place to house this cross-reference

You're right :)

So, I personally do not want to know any specific "What's the best bulb for the front turn signal on a 2025 Ford Model T?" But I do want people who have acquired an answer to that question using one bulb numbering scheme to use the cross-reference to see the other identifiers for that bulb.

You're mixing terms here. Only a very few bulbs have more than one designation or "identifier". The list looks something like this:

HB1 (9004)
HB2 (9003)
HB3 (9005)
HB4 (9006)
HB5 (9007)
HIR1 (9011)
HIR2 (9012)
H3 (9200 which nobody ever says)
3057 (2457 which nobody ever says)
3157 (2458 which nobody ever says)

Maybe in the whole wide world of bulbs for cars there might be two or three more...but that's it, so right there is your cross reference for bulb identifiers. So which is it that you think you want? A cross reference for bulb identifiers, or a cross reference for different brands' order numbers?

The level of precision on that package image I posted that says 2825 also fits 168/194 is I think a perfectly acceptable level of cross-compatibility

But you're wrong. "2825" (W5W), 168, and 194 are not the same bulb. They will fit each others' sockets, but you cannot just assume they will safely and effectively work interchangeably, because they won't necessarily.

Basically whatever granularity the standard bodies have should drive the row count as a general rule. Differences in vendor part numbers would not be enough.

Wait, so you do want a cross reference for identifiers, which is necessarily short because there aren't many bulbs with more than one identifier/more than one direct and identical cross.

Yes people to find compatible bulbs every day already, but from personal experience I would not describe the process as "without difficulty".

What difficulty did you experience? What were you trying to find?

I assumed that SAE came up with the numbers because I cannot find any ANSI standard that defines them.

Careful. Have you been made aware of what happens when you assume? It looks like you might want to start here in your quest to discover the roots of American vehicle bulb designations.

So it's being controlled nowadays perhaps by the collective alone

Consider the lessons to be learned by examining the history of sealed beam headlamp identifiers. There used to be a structural system of designation. The first digit designated the size, the second and third digit differentiated same-size lamps from one another, the fourth digit designated the beam pattern(s), and the suffix, if any, designated the lens color or other variant.

6012: "6" = PAR56 lamp, "01" = not intrinsically meaningful, "2" = a type-2 unit producing a low and high beam.

4002: "4" = PAR46 lamp, "00" = not intrinsically meaningful, "2" = a type-2 unit producing a low and high beam.

4001: "4" = PAR46 lamp, "00" = not intrinsically meaningful, "1" = a type-1 unit producing a high beam.

The listings also included 6012A (an "amber" yellow-lens version), 6012LH (a left-hand traffic version), etc.

Then the lamps were improved in the mid-'60s. 6012 gave way to 6014 and 4002 gave way to 4000. Oops, that breaks the designation system! No longer is the final digit meaningful.

Then came rectangular headlamps in the 1970s: 4652 high/low beam and 4651 high-beam small rectangular. OK, the final digit still gives us our type-2 or type-1, but now we're using the first two digits to specify the lamp size, roughly 4 x 6 inches. Meanwhile the large rectangular was a 6052. This fits the system OK if we ignore that the same digit 6 was used for a large rectangular as for a large round headlamp.

Then came halogen sealed beams and for a short while everything was fine: H4000, H4001, H6014, H4652, H4651, H6052.

Then came the American auto industry's drive to take money out (make them cheaper) so H4000 and H4652 with the same 40/60w rating as a tungsten 4000 and 4652 gave way to H5006 and H4656 with 35/35w rating, H6014 and H6052 with 65/55w filaments gave way to H6024 and H6054 with 65/35w, at the same time the designations became arbitrary.

Then came the high-performance large round and large rectangular halogen sealed beams with 65/55w filaments...but they weren't called H6014 and H6052, now they were called H6024XV and H6054XV (Sylvania), H6024HO and H6054HO (GE), H6024NH and H6054NH (GE), H6024BL and H6054BL (Wagner). Can't tell the filament wattage from the designation any more.

Then came late-production halogen sealed beams sold as high-performance, but with low-wattage filaments: can't tell these H6024NH and H6054XV from the earlier-production ones with the higher-wattage filaments.

And then on the other hand you have designations that have not changed at all. A basic 1157 made in 1977 is highly similar to a basic 1157 made last month.

So don't elevate the designations to a level of meaning they don't have, is the point.

So they are car model-specific documents dedicated to bulb identification? Wow, where can I find them?

Well, here and here and here and here and here and here and here, for example.
 
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scootley

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You're mixing terms here. Only a very few bulbs have more than one designation or "identifier". The list looks something like this:
...
Maybe in the whole wide world of bulbs for cars there might be two or three more...but that's it, so right there is your cross reference for bulb identifiers.

But you're wrong. "2825" (W5W), 168, and 194 are not the same bulb. They will fit each others' sockets, but you cannot just assume they will safely and effectively work interchangeably, because they won't necessarily.
...
Wait, so you do want a cross reference for identifiers, which is necessarily short because there aren't many bulbs with more than one identifier/more than one direct and identical cross.
Ah ok sorry for confusing. Thanks for bringing up this key point again. I understand that 2825 (W5W), 168, and 194 are not the same bulb. But if Osram's packaging for a 2825 says it fits and is compatible with 168 and 194, then isn't it true that these cases where they would not work interchangeably safely and effectively must be rare? Otherwise they would have a lot of customers yelling at them for essentially claiming what most people would interpret as equivalence on the package?

If non-interchangeability between those bulbs is rare, then I would want the cross-reference to list them as interchangeable as one of its key pieces of data.
And yes in addition to that kind of listing, I would also want to cover the cases of a single bulb actually having two standardized identifiers (like HB1 = 9004).
So two types of cross-reference would exist in this table.

We have the internet now, so whoever wants to find out the order number or EAN or SKU is for any particular brand of any particular kind of bulb can easily do so.
...
So which is it that you think you want? A cross reference for bulb identifiers, or a cross reference for different brands' order numbers?
Good point. Actually I was thinking about this in between posts and as long as a given manufacturer uses at least one of the {ECE, NHTSA, ANSI} numbers on all of their products labeling, there is no reason to include that company in the cross-reference. I am less concerned with SKU's and part numbers than just the cross reference between standard identifiers. I was worried originally that there were a meaningful number bulbs out there that ONLY have a vendor part number and no standards-body identifier.

If they learn that a 3652 is the best bet for whatever they're trying to do, they can search for 3652 bulb plus whatever brand name they prefer and find a vendor.

If that vendor does not use 3652 commonly in their product listings or packaging, but uses (if one exists in this hypothetical example) only ECE identifiers, then such a search would not necessarily yield good results. This is exactly why someone would want to cross-reference 3652 to its ECE equivalent and then search for both identifiers


What difficulty did you experience? What were you trying to find?
I can't remember the details any more but it was for some kind of interior bulb.

It looks like you might want to start here in your quest to discover the roots of American vehicle bulb designations.

I did look at ANSI C78.390-2006 in my search before because it is also cited in J573. But C78.390-2006 does not actually list the set of identifiers that have been standardized. I believe in section 3.2 it just says that the other document I mentioned (ANSLG SR25d-1997) is the one that actually has the list (e.g. for miniatures). C78.390-2006 just described the process for a bulb manufacturer to ask ANSLG to assign an identifier. I am looking for the list of identifiers that have already been created/assigned to date.

Side note: What's funny is that C78.390-2006 explicitly says "The lamp characteristics data given by a manufacturer ... forms the basis for the assignment of a designation. They have not been approved by the American Standards Institute (ANSI) and do not constitute an American National Standard." So apparently SAE just takes the list from ANSI (perhaps via the elusive SR25) and then uses it to submit their definition of lamp characteristics using those identifiers back to ANSI to actually standardize them, as J573 is in fact "Submitted for recognition as an American National Standard". Seems a bit roundabout.

Well, here and here and here and here and here and here and here, for example.
Yeah definitely have seen those already. I was looking for a document written by the car manufacturers for each of their car models (owners manuals do not always have this info) because when you said "there's one guy in America who hand-gathers the bulb application info for most of the makers' application guides ... and he did it in a very low-tech manner: he went to car dealers", I thought the term "makers'" there meant car makers, but you meant bulb makers.

So don't elevate the designations to a level of meaning they don't have, is the point.
Yes I have always been a firm believer that:
1) If you have a set of more than ~5 things, each thing needs to have a unique identifier
2) Those identifiers should not themselves encode attributes of the things that they identify. They should just be identifiers and nothing else.
 

-Virgil-

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Messages
7,802
I understand that 2825 (W5W), 168, and 194 are not the same bulb. But if Osram's packaging for a 2825 says it fits and is compatible with 168 and 194, then isn't it true that these cases where they would not work interchangeably safely and effectively must be rare?

That depends. The Sylvania LED bulb you found that "compatible with 2825, 168 and 194" on will cause problems in applications where the bulb has to light up no matter which direction (polarity) current is applied. Sidemarker lights that are wired to flash with the turn signals, for example, and single dashboard turn signal indicators that flash whether the left or right turn signal is on. There are other safety and performance issues that can arise when substituting an LED like this in place of an incandescent bulb, that are not really the point of this conversation, but there are vehicle damage hazards even if you just consider replacing a 194 or W3W with a 168 or W5W. The extra 2 watts or so probably isn't enough to cause any electrical issue if it's just one bulb we're talking about. But if you have five or ten bulbs on a common circuit (dashboard lights) the extra current can add up to too much. And then there's the heat issue: yes, there really are lamps, interior and exterior, that will tolerate a W3W or 194 for prolonged usage not a W5W or 168 (or 3652, 2886X...). You can't see this ahead of time with your eyes, or detect it otherwise, so a weak little warning footnote is going to be useless in a document presenting itself as a 'cross reference'.

I am less concerned with SKU's and part numbers than just the cross reference between standard identifiers.

"Cross-reference" implies identicality, or at least full functional equivalence.For the 3rd (and let's make it final) time, there are very few bulbs that have actual crosses to other identifiers.

I was worried originally that there were a meaningful number bulbs out there that ONLY have a vendor part number and no standards-body identifier.

Very few of those.

the other document I mentioned (ANSLG SR25d-1997) is the one that actually has the list (e.g. for miniatures). C78.390-2006 just described the process for a bulb manufacturer to ask ANSLG to assign an identifier. I am looking for the list of identifiers that have already been created/assigned to date.

Then buy the up-to-date version of SAE J573. SR25d-1997 is 22 years old.

I was looking for a document written by the car manufacturers for each of their car models (owners manuals do not always have this info)

Parts manuals and/or service manuals published by the automaker do.

If that vendor does not use 3652 commonly in their product listings or packaging, but uses (if one exists in this hypothetical example) only ECE identifiers, then such a search would not necessarily yield good results.

Poor choice of example because 3652 has no ECE (or other) identifier, but even if we substitute a better example (say 2825/W5W) I don't think you're right about this. I just don't think it's very difficult or time-consuming to figure out the information you think is so difficult to find, using standard internet searching. Whatever, that's fine, you and I don't have to agree. But we do already agree that this forum is not the home for your "cross reference" project, so...I guess we're just about done with this line of conversation, then, right?
 

scootley

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Messages
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Then buy the up-to-date version of SAE J573. SR25d-1997 is 22 years old.

Sorry to go back and forth. My objective there is to find a complete list of all ANSI automotive bulb identifiers. Since SAE doesn't come up with them, I assume they are in an ANSI document as the primary source. We have not yet established if such a document exists; my research would indicate that it is ANSLG SR25 (and SR26), but I have no idea where to find it online (maybe I should call ANSI). So I have e.g. SAE J573 from 2011, which is the newest version, and it still cites ANSLG SR25 (2009). If you happen to know that SAE J573 (and J2560) does in fact contain every ANSI bulb identifier even though SAE does not create the identifiers, then yes I can use it as a substitute for ANSLG SR25. Since I cannot see ANSLG SR25, I cannot myself verify that the identifier list between it and J573/J2560 is identical.
 
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