17 November 2016

Milspec

Been calling around attempting to get someone to do a Type III Class 2 (black) anodizing on my M16A2 clone lower.

Hardly anyone can do the hard-coat that Type III is.

Lots of places obfuscate by attempting to sell me Type IIB Class 2 by saying it's in accordance with MIL-A-8625.

I happen to have a copy of that!

3.4.2 Type II and IIB coatings. Type II and IIB coatings shall be the result of treating aluminum and aluminum alloys electrolytically in a bath containing sulfuric acid to produce a uniform anodic coating on the metal surface. Heat treatable alloys shall be in the required temper obtained by heat treatment, such as -T4, -T6, or T73, prior to anodizing. 
3.4.2.1 Type IIB coatings. Type IIB coatings provide a non-chromate alternative to Type I and IB coatings. Unless approved by the procuring activity, substitution of a Type IIB coating where Type I or IB is specified shall be prohibited. 
3.4.3 Type III coatings. Type III coatings shall be the result of treating aluminum and aluminum alloys electrolytically to produce a uniform anodic coating on the metal surface. Type III coatings shall be prepared by any process operation to produce a heavy dense coating of specified thickness on aluminum alloys (see 3.7.2.1). Unless otherwise specified in the contract, purchase order or applicable drawing, Type III coatings shall not be applied to aluminum alloys with a nominal copper content in excess of 5 percent or a nominal silicon content in excess of 8.0 percent. Alloys with a nominal silicon content higher than 8.0 percent may be anodized subject to approval of the procuring activity. Heat treatable alloys shall be in a temper obtained by heat treatment, such as -T4, -T6 or T73, prior to anodizing.

When you ask, "do you properly adhere to section 3.4.3," they start equivocating start saying that Type II is good enough.

Except it isn't for the hammer, selector and trigger pin holes.  Type II just isn't resistant enough to wear for even casual use for very long.  You'll end up with an oval hammer hole in short order.

I have found a place that can actually do the work and is willing to do it!  Road trip tomorrow morning!

4 comments:

  1. Hi Angus,
    Funny you should mention that!!! Good ol "Mil-Spec" Besides the metal stuff, try buyin' any "Para-cord" lately?? Unless it is "Mil-C-5040, Type III" "550 lb. test" it's some bunk 80 lb. test Chinese stuff!!! Not Mil-Spec, it's not The "Real McCoy!!!"
    "The old 'Rigger,"
    III%,
    skybill-out for now FAA Master Parachute Rigger (Chest, Back and Seat)

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    Replies
    1. As a matter of fact, I have bought some "para-cord" lately. Dakota Gear proclaims on their packaging, "Genuine Type III 7-strand 550 Paracord" on the stuff I bought for my arts & crafts project. They don't mention MIL-C-5040. But since they also say "100% polyester (as good or better than nylon)" they're probably not mil-spec. They do say "break strength 550+ pounds" though.

      I don't think my little bottle lanyards we're giving away to the Special Olympics bowlers will ever be subjected to what cheap Chinese cord can do (though this is cheap American cord). I bought it based on color, not strength.

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  2. Hi Angus,
    10-4.... For arts and crafts stuff or the like all that is good...... I worked in the Aero Space Parachute industry pretty much all my working life..... We used the "Real McCoy!!" Still have a bunch of Cord and webbing that got "Dumped" at the end of a contract..... Good stuff!!
    Blue Skies,
    skybill-out

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    Replies
    1. I've got some genuine OD green stuff around here someplace too. You can tell them apart readily by looking at the cores.

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