Manufacture of Military
Helmet
Military Helmet according to MIL-
STD662E
Contents
Preamble to MIL-STD-662E/F
Reverse engineering of a LEVEL-II Protection
shell
Specifications of a LEVEL-III Protection helmet
Current and proposed manufacturing techniques
Resistance Testing
MIL-STD 662E Level-III / A
Purpose
The purpose of this standard is to provide general guidelines for procedures, equipment, physical conditions, and
terminology for determining the ballistic resistance of metallic, nonmetallic and composite armor against small arms
Projectiles. The ballistic test procedure described in this standard determines the V50 ballistic limit of armor.
Level IIIA is the fourth level of protection
8 g (124 gr) 9 mm FMJ RN bullets at a velocity of 398 m/s ± 9.1 m/s (1305 ft/s ± 30 ft/s)
10.2 g (158 gr) .357 Magnum Jacketed Soft Point bullets at a velocity of 436 m/s ± 9.1 m/s (1430 ft/s ± 30 ft/s).
8 g (124 gr) 9×19mm Parabellum Full Metal Jacketed Round Nose (FMJ RN) bullets at a velocity of 373 m/s ± 9.1 m/s (1225 ft/s ± 30 ft/s)
11.7 g (180 gr) .40 S&W Full Metal Jacketed (FMJ) bullets at a velocity of 352 m/s ± 9.1 m/s (1155 ft/s ± 30 ft/s)
14.9 g (230 gr) .45 ACP Full Metal Jacketed (FMJ) bullets at a velocity of 275 m/s ± 9.1 m/s (900 ft/s ± 30 ft/s).
2.6 g (40 gr) .22 Long Rifle Lead Round Nose (LR LRN) bullets at a velocity of 329 m/s (1080 ft/s ± 30 ft/s)
6.2 g (95 gr) .380 ACP Full Metal Jacketed Round Nose (FMJ RN) bullets at a velocity of 322 m/s (1055 ft/s ± 30 ft/s).
MIL-STD 662E Level II Protection Shell
MIL-H-44117A
Cloth Ballistic Aramid
Mil-spec (type II, class I of MIL-
C-44050)
Type II - 14.0 oz/sq. yd.
320gm/sqm Class 1 - Untreated
– (scoured)
Laminating Resin
50% Phenol formaldehyde and
50% PVB
Total Shell Thickness
3mm for 10 plies
Coating
MIL-C-46168 Color Olive, with
Silica sand or Walnut Flour
MIL-STD 662E Level-III / A
Ballistic PASGT Helmet | Military Level IIIA Helmet
NIJ 0101.06 – Level IIIA Tested to meet or exceed
V50 Ballistic Test for Armor, DOD MIL-STD 662E
Tested for Penetration and back face deformation
Standard PASGT design (MIL-H-44099A)
Tested to defeat: .357 Magnum, .44 Magnum, .9mm,
.357mm, .40 S&W FMJ rounds
Dimensions: Shell Thickness 7.3 +/- 0.8.
Weight 2.9lbs
Manufacturing
Closed Mold Pressure Molding
Curing cycle of Phenolic resin is 180°C for
one hour and 140°C for 4 hours
Granular Bakelite® may be used to flow at
90°C and cure at 140-180°C for an hour
Biaxial Type II Kevlar 29 / Aramid mat 0.27-
0.30mm thickness
Phenolic Resin as per original design may be
converted to epoxy for ease of manufacture
Moulds may be mass produced by stamping
Mild Steel / Aluminum shells from a master
die.
Vacuum formed / Injection Moulded
polycarbonate shell may also be lined with
kevlar pheolic/epoxy for ease of
manufacture.
Manufacturing
Phenolic Formaldehyde / Bakelite®
Kevlar 29 mats to be pre-impregnated with PF and PVB resin
mix, PU may also be used.
Kevlar sheets are cut in pinwheel patter as per MIL-H-
44099A
A 10 Ton force may be sufficient to produce a pressure in
the closed mold of around 10 bar per helmet
Multiple molds per die e.g. 4 Helmets per die will ramp up
the pressure requirement to 40 ton
Testing
Projectile resitance
The helmets are to be tested according to the already quoted MIL-STD-662
A whitness plate to be placed inside the Helmet of 2024-T3/T4 Alminum alloy of 0.51mm thickness
Penetration at V50 is recorded when the witness plate is completely punched through.
