Mil-Spec III Aluminum Anodizing Durability

yinyang

yinyang

Joined
Jun 16, 2004
Messages
657
What's the deal, fellas? After reading a bit about the durability of 'normal' aluminum anodizing( i.e. pretty weak), I came to the conclusion that 'type 3' anodizing was pretty tough. However, my Gerber Yari II, WITH type 3 anodizing, just took a hefty nick after sitting down on it next to a seatbelt buckle. Now, I didn't even notice the severity of the scratch upon sitting down; I had to think about how it happened. Now my handle has an obvious shiny dent/scratch. What is the bloody difference between normal anodizing and type III IF they both tend to booger up this easily???
 
The difference is that type 3 will often abrade metals, coins will not scratch it. No matter how hard the type3 anodizing is however, the aluminum beneath it is much softer than hardened chrome plated steel belt buckles. If you press hard enough the aluminum will deform, and the anodizing will along with it. Regular anodizing will often look scuffed and worn from incidental contact with pocket change. Type 3 will pick up marks but they can usually be scrubbed off as the anodizing itself is not damaged.
 
Type 3 or Hard Anodizing will, as yoda said, dent, nick and deform because of the underlying aluminum which is fairly soft. But the coating itself is very hard and should not wear easily. I have heard of chipping but never seen it happen. The corners and edges are always the first to go with HA.
 
Depends on the integrity of the anodizer . Surefire I trust , cr## from the PRC is questionable . Benchmade is pretty durable .

Chris
 
johnu2 said:
If its type 3 anodizing, does that automatically make it mil spec?
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Not really.

It is Military specification MIL-A-8625 that creates the term "Type III" anodizing. That specification defines TYPE III as Hard Anodize and gives a set of properties that such anodize films must have. The specification also sets up testing requirements for the films and for the process tanks that are used to produce the films. In order for an anodize finish to be MIL-A-8625 TY III, both the film and the process line have to meet all of the requirements of the specification.

Sometimes folks use the term "TYPE III anodize" to mean hard anodize. But you can have a hard anodize finish and not meet all the requirements of the specification. Such films cannot be said to be MIL-A-8625 Type III.

When I specify hard anodize and want it done to the MIL spec with all the associated testing and certifications, I specify the full spec callout, "MIL-A-8625 TY III". (and those tests and certs cost extra.)

Sorry the answer is a bit convoluted, but, welcome to my world. (M&P engineering)
 
Thanks for the heads up guys...looks like I might be ditching the aluminum scales in favor of paracord.
 
I've never scratched HAIII anodizing on any of my knives or flashlights (Fenix lights don't count--they're not "true" HAIII). I have however dinged them a couple times, and they mark up some if rubbed against coins, keys, or metal pens, but these aren't scratches, they're actually just the softer metal rubbing off into the HAIII.
 
Planterz said:
I've never scratched HAIII anodizing on any of my knives or flashlights (Fenix lights don't count--they're not "true" HAIII). I have however dinged them a couple times, and they mark up some if rubbed against coins, keys, or metal pens, but these aren't scratches, they're actually just the softer metal rubbing off into the HAIII.
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I think it is either called HA or Type3, but not HAIII
 
"hardcoat" anodizing is a conversion coating where the surface of an aluminum part is converted to aluminum oxide, a ceramic. This is the same stuff used in some sandpaper so, as you can imagine, it is pretty hard stuff. It is usually only done a few thousandths of an inch deep (actually, it "grows" about the same amount as it penetrates the surface). It resists abrasive wear very well (since it is used as an abrasive itself) but it is not resistant to gouging since it is only a thin layer and the aluminum substrate underneath is so soft. You can rub it against almost anything without problems but don't scratch it with anything harder than aluminum.
 
Well, you can count me as a member of the aluminum scales suck club. I ditched them for paracord. I know it's being anal retentive, but I am what I am. Can't stand a new toy looking played out.
 
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