Other Standard Grommet Mount Lamp Sizes???

We're all aware of the two standard "sealed-lamp-in-grommet" sizes, since Truck-Lites became popular more than 30 years ago. Most common was the round size, same as PAR36, then came the oval, about 2.25 x 6.5 inches. I've also seen small diameter sealed, grommet mounted clearance/marker lights.

Some time back, I bought a nice LED rear fog that came with a rubber grommet. It's a rectangle (rounded corners, of course), a bit taller than than the standard oval, and a bit shorter. I don't have it in front of me at the moment, but let's say around 4 high by 5½ or 6 wide.

I find myself wondering if there are other more or less standardized sizes for grommet mounted, sealed tail, signal, backup or work lights. Is there anything else out there?

Thanks.

Hamilton Felix said:

We're all aware of the two standard "sealed-lamp-in-grommet" sizes, since Truck-Lites became popular more than 30 years ago. Most common was the round size, same as PAR36

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Not the same as PAR36. PAR36 is nominal 4.5" diameter. The standard round size you're thinking of is nominal 4" diameter. This is why whenever you see a truck where the owner has tried to "retrofit" reversing lamps or rear work lights by installing a set of PAR36 sealed beams in a circular cutout intended for the standard round signal lamps, the sealed beams are always cocked at a drunken angle and never fit right -- they are too big for the hole.

the oval, about 2.25 x 6.5 inches

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Close, 2.32" x 6.5".

Some time back, I bought a nice LED rear fog that came with a rubber grommet. It's a rectangle (rounded corners, of course), a bit taller than than the standard oval, and a bit shorter.

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3.44" by 5.3".

I find myself wondering if there are other more or less standardized sizes for grommet mounted, sealed tail, signal, backup or work lights.

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Those are the ones. There are some larger ones (7" round, 5" x 7" rectangular) but they don't come in grommet-mount.


Thanks.[/QUOTE]

-Virgil- said:

Not the same as PAR36. PAR36 is nominal 4.5" diameter.

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For fans of arcane knowledge, the number after the "PAR" designation is the lamp's diameter, expressed in eighths of an inch.

A PAR36 is 36/8", or 4.5". A PAR46 is 46/8", or 5.75"

Interesting. Thanks, Virgil. I thought I had at some time in the past mounted PAR36 sealed beams in those rubber grommets. I guess if I did, I only succeeded because I was cutting the openings in the metal, not using Truck-Lite brackets. Rubber stretches.

I will say that, long before the advent of LED lights, those sealed Truck-Lites came as a blessing to logging trucks, gravel hacks and many others in dirty or wet environments. I can't tell you how many park/tail/signal/clearance light failures I've seen due to dust, corrosion, water, etc.

Yep, eggsalad, Parabolic Aluminized Reflector, 36 eighths in diameter. BR (Bulged Reflector) and MR (Metalized Reflector, if memory serves) lamps also describe diameter that way. Seems odd until you get used to it.

Afterthought: I'm guessing that these standard grommet mounted lights are used exclusively for tail/marker/signal/backup/work lights. People hang all sorts of lights under their front bumpers as fog lights/decorations, but I'm guessing there are no actual fog or driving lights made in these standard dimension. Right?

Correct -- they are signal and marking lamps only.