How easy to scratch HA3 with a knife?

I've heard of people showing friends how hard their flashlight's HA3 is by trying to scratch it with a pocketknife or something...

How confident are you guys in doing this? i kinda jabbed at mine:touche: with a kitchen knife but chickened out before i put any pressure behind it.

No scratches

but... Have you ever "tried" scratching HA3 with a piece of metal? anyone ever "acidentally" succeed and ruin a perfectly good finish?

Just curious...

I would be kicking myself if I tried it intentionally and the HA failed to hold up. But once I accidentally slipped with a knife and the blade smacked into the tailcap of my A2, causing a very tiny pinprick of silver to appear on the finish. Upon closer inspection, it appears to be a small chip in the HA.

The HA (aluminium oxide) growth is harder than blade steel but the aluminium alloy substrate isn't. To see exactly what is going on it would be better to view the experiment under a magnifying glass or similar.

Al

yeah, I'd kick myself too... but I hear of others doing it all the time.:shrug:

I had some tiny marks that i thought were scratches near the bezel... In another thread I was told how to clean it up. turns out the scratches were, indeed, scratches, but scratches from my cell phone and keys... the paint/metal filings apparently stuck to the A2.

My poor cell phone got placed in the same pocket as the A2 for an hour long flight... the cell phone looked almost new before the flight (about two weeks old) and after looked like I've been beating it up for years the poor thing.

Size15's said:

The HA (aluminium oxide) growth is harder than blade steel but the aluminium alloy substrate isn't. To see exactly what is going on it would be better to view the experiment under a magnifying glass or similar.

Al

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soooo... not to put words in your mouth, but I understand you are saying that...

the finish should hold up to scratching but any forces strong enough to reach the substrate will dent the underlying metal and thus damage the finish?

anyone have an old Ha3 light and a magnifying glass and a camera handy?

You can't test anodization hardness like you can with steel, because the aluminum is too soft underneath. It's better to go with an abrasion resistance test. I remember reading that abrasion tests rate HAIII to the equivilent of Rc hardness well into the 90s. Most premium steels are hardned to around 60Rc. Even the newest supersteels like ZDP-189 top out at 65-67Rc (which is damned hard for a cutlery steel). So if the HAIII is well done and at a proper thickness, you shouldn't be able to scratch it with a knife, short of gouging, denting, or otherwise deforming the aluminum underneath.

I find that most "scratches" I get with HAIII objects in my pockets is actually the other material (like keys or coins or metal pens) that has been rubbed off by the HAIII and is now imbedded in the surface.

When you hit an Millennium TurboHead (I believe it was an M3T) with a hand-axe used for splitting kindling you can damage the substrate

I don't have any real up-close photos to show what 'normal' abusive knife-work does to HA...

Why would you want to mess up a perfectly good light?

I rembember on some watch forum a guy scratched his $800 Sinn watch on all edges because it was supposed to be scratch resistant. It wasn't.

I think I'm going to cry!!!

Size15's said:

When you hit an Millennium TurboHead (I believe it was an M3T) with a hand-axe used for splitting kindling you can damage the substrate

I don't have any real up-close photos to show what 'normal' abusive knife-work does to HA...

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Planterz said:

I find that most "scratches" I get with HAIII objects in my pockets is actually the other material (like keys or coins or metal pens) that has been rubbed off by the HAIII and is now imbedded in the surface.

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Yep - it looks like a scratch through the HA but it's usually whatever you scratched the HA with that is trapped in the HA structure (which is lots of tiny pits)

I was asked to see how well it handled abuse. The bulb did not fail.
There comes a point when you're trying to find out how much abuse a SureFire can take when you stop being rational and have to start throwing caution to the wind. In fact some of the best abusive field-testing is throwing flashlights to the wind but that's for another thread perhaps.

Al

P.S.
Millennium TurboHeads grow on trees right?

Chronos said:

I think I'm going to cry!!!

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:mecry: :mecry:me too :grouphug:

I didnt know graphic pics like that could be shown in here :mecry:

Size15's said:

I was asked to see how well it handled abuse. The bulb did not fail.
There comes a point when you're trying to find out how much abuse a SureFire can take when you stop being rational and . . .

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BEAT IT WITH AN AXE!!! BWAHH HAA HAA HAAAAA!:eeksign:

so, in general, taking a friends pocket knife and firmly trying to scratch the surface of the bezel on an A2 should be safe? anyone ever try it and fail?

OK, Ok, that is pure flashlight p0rn. I think I need a smoke after that! :laughing:

Resistance is failing, I need to get my first Surefire. I think I'm going to ask for an L6 for my bday.

Size15's said:

I was asked to see how well it handled abuse. The bulb did not fail.
There comes a point when you're trying to find out how much abuse a SureFire can take when you stop being rational and have to start throwing caution to the wind. In fact some of the best abusive field-testing is throwing flashlights to the wind but that's for another thread perhaps.

Al

P.S.
Millennium TurboHeads grow on trees right?

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I don't see why you'd want to scratch your flashlight just to see whether it will be ruined as a result. I have the luxury of having samples specifically to abuse - to see what it takes to ruin them.
For example: M2 shock isolated bezel proto-types:


I do not for one moment suggest you try to scratch your flashlight.

Al

Size15's said:

I don't see why you'd want to scratch your flashlight just to see whether it will be ruined as a result. I have the luxury of having samples specifically to abuse - to see what it takes to ruin them.

I do not for one moment suggest you try to scratch your flashlight.

Al

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yeah, technically, picking up a red hot coal and shaking it between your hands quickly enough is "safe" and it wont burn you, but i dont make a habit of doing so ;-)

I was kinda hoping for some embarrassing stories from the community.

but, barring that...

Have you ever ruined any of your spare surefire samples?

Sgaterboy said:

Have you ever ruined any of your spare surefire samples?

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PK has sent me various proto-type and pre-production samples to be field-tested abusively - they were not spare until after I was done with them!

Al

Size15's said:

PK has sent me various proto-type and pre-production samples to be field-tested abusively - they were not spare until after I was done with them!

Al

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sounds like a similar career choice as one of those guys who shoot frozen chickens at airplanes...

http://home.xnet.com/~warinner/chickref.html

man, I was BORN for that job :rock:

like that is better.

:lolsign:

barnabe said:

like that is better.

:lolsign:

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HAHA!! THANKS!! :laughing: :goodjob: now I won't be embarrassed to show my mother this website