MIL-PRF-32432 vs MIL-PRF-31013: the old spec, the current one, and what the 'A' means

The short version

If you are choosing between two pairs of glasses and one says 31013 while the other says 32432, buy the 32432. It is the current specification, it is the one the U.S. Army's Authorized Protective Eyewear List is built around, and the fragment velocity it requires for spectacles is higher. If one says 32432 and the other says 32432A, they are the same specification and the A is a revision letter — choose on the rest of the spec sheet instead.

Everything below is the detail behind those two sentences, including what the velocity numbers are actually measuring and why a "V50" figure is worth more than any of the standard names.

The two specs side by side

The 31013 figures are from the ballistic eyewear overview cited below; the 32432 velocity is Edge Eyewear's own description of the test its tactical line is built to; the ANSI figures are from the Z87.1 explainer. Where a source gives a range we print the range rather than picking a number inside it.

Two readings matter in that table. First, the gap between the civilian and military tiers is enormous — a quarter-inch ball at about 150 ft/s against a fragment simulator at four times that velocity. Gatorz, whose comparison we cite, makes the same point in terms of test energy. Second, both military specs are testing fragmentation, which is shrapnel, not a bullet. Nothing on this site stops a bullet, and no maker claims it does. The full version of that argument is on ANSI Z87.1 vs MIL-PRF-32432.

MIL-PRF-31013: the older spec

MIL-PRF-31013 is the specification most of the ballistic eyewear of the 1990s and 2000s was built to, and it is the reason so many much-loved frames still carry its number. It set out two classes with different projectiles: for spectacles, a 0.15 calibre T37 fragment simulating projectile at roughly 640 to 660 feet per second; for goggles, a 0.22 calibre projectile at about 550 to 560 feet per second.

You may notice something counter-intuitive there — the goggle test uses a bigger projectile at a lower velocity. That is deliberate rather than a loophole: a goggle covers more area and sits further from the eye, so the threat profile it is being tested against is different.

If a pair of glasses in front of you states 31013 and nothing else, it is not bad eyewear. It is eyewear whose certification paperwork is a generation old, which in a category where the standard has moved on is a reason to prefer something current — and the practical reason is procurement rather than physics: the Army's list is built on the newer specification.

MIL-PRF-32432 and the MCEPS family

MIL-PRF-32432 is the current specification, and it comes with a piece of vocabulary that confuses almost everybody: MCEPS, the Military Combat Eye Protection System. Edge Eyewear describes MIL-PRF-32432 as a classification of MCEPS, and states that eyewear tested for compliance with it must withstand the impact of a 22-calibre projectile travelling at more than 660 feet per second.

You will also see the string MCEPS GL-PD 10-12 on product pages — Walker's prints it for the IKON Tanker, and the retailer listing for the Edge Hamel pairs it with ANSI Z87.1+2010 and EN 166. Treat it as the same family of military ballistic wording rather than as a separate, higher claim.

The thing MIL-PRF-32432 enables, and 31013 no longer does, is the APEL. The Authorized Protective Eyewear List is managed through the Army's programme offices, and the APEL logo on a pair is how the Army marks eyewear authorised for issue; a listing implies the configuration passed MIL-PRF-32432 fragmentation testing and was approved. That makes the APEL the strongest third-party signal available in this category — with the caveat that it applies to a configuration, not to a model name. The whole list, and what it does and does not prove, is on the APEL approved eyewear list.

What MIL-PRF-32432A actually means

A great many people search for "MIL-PRF-32432A" specifically, so let us be exact about it. In the U.S. defence specification system a trailing letter is the revision of the document. MIL-PRF-32432A is revision A of MIL-PRF-32432. It is not a higher grade, a stricter class or a premium tier, and a pair stating 32432A is not more protective than one stating 32432 by virtue of the letter.

What the letter does tell you is how recently somebody wrote the product page. Wiley X states "MIL-PRF-32432A Ballistic safety standards" on the Saber Advanced, the Vapor and the Gravity. ESS states "U.S. MIL-PRF-32432A" on the Crossbow APEL kit page and plain "MIL SPEC MIL-PRF-32432" on the Profile NVG and Crosshair pages. Edge writes "MIL-PRF 32432-A" with the hyphen in a different place. Revision goes furthest and cites the clause: "MIL-PRF-32432A clause 3.8.4.1 Ballistic fragmentation characteristics Class 1 spectacles".

Military V0, V50 and the numbers makers quote

Three more pieces of wording, in rough order of usefulness.

V50 is the velocity at which half the shots would be expected to penetrate — a measured threshold, not a marketing figure. Revision publishes a STANAG V50 of 807 ft/s for the StingerHawk. It is the only published velocity number on this site, and it is worth more than any standard name because it is a result rather than a claim of compliance.

Military V0 is older wording for a zero-penetration result at a stated velocity, and it still appears on long-serving products. Honeywell uses it for the Genesis Sharp-Shooter: clear and amber lenses "meet Military V0 ballistic impact test requirements (7X higher than ANSI)". Note what that sentence does and does not cover — it names two lens colours, and the vermillion lens is not in the statement. That is exactly the kind of detail that disappears when a retailer summarises a spec.

"Tested to" is the weakest of the three and it is deliberately different from "compliant with" or "certified to". The Magpul Defiant is reported as tested to MIL-PRF-32432 ballistic standards rather than certified, and our card says so in plain words. It is not an accusation — it may simply be how the brand chooses to phrase an uncertified internal test — but you should know which you are buying. The checks are on how to tell if glasses are ballistic rated.

Picks by wording

The whole MIL-PRF tier ranked by rating rather than by wording is on best ballistic glasses, and the fragment test itself is pulled apart on MIL-PRF-32432 explained.

What to do with this at the checkout

Four rules, in order.

Prefer 32432 to 31013. Current specification, higher spectacle velocity, and the basis of the APEL.

Ignore the revision letter. 32432 and 32432A are the same specification. Decide on fit, coatings, lens kit and warranty instead — the brand-level comparison is on best safety glasses brands.

Check which part of the product the claim covers. Honeywell's V0 statement covers two lens colours. The APEL covers a configuration. A ballistic claim that does not say what it applies to is worth less than one that does.

Remember that most people do not need this tier at all. For a range day, a clays course or a workshop, ANSI Z87.1 with the high-impact plus is the right answer and the money is better spent on fit and tint. The honest version of that argument is on Z87 vs Z87+.