British Armour Specifications / Penetration Criteria

Plate Specifications

Code	Type
I.T.60	Thin face hardened plate
I.T.70	Homogeneous hard plates 3 to 14mm thick
I.T.80	Machineable quality plates 15mm thick and over
I.T.90	Cast armour
I.T.100	Machineable quality plates 3 to 14mm thick
I.T.110	Heat-treated Carbon Manganese steel

Penetration Codes

Code	Result
A	Slight or no impression
B	Deep impression
C	Deep impression and bulge at back
D	Deep impression and bulge at back and crack
E	Deep impression with flak off the back of the plate, or bulge and crack
P	Pinhole penetration
R	Penetration, core not clean through the plate
W	Penetration, core clean through
L	Indicates core lodged in plate i.e. P(L)

Penetration Criteria

Ballistic limit - the striking velocity at which there is a 50% chance of getting daylight through the plate or of metal being thrown from the back of the plate.

Immunity level - highest velocity which would give only a smooth bulge on the back of the plate

W/R Limit - the striking velocity at which half give "W" and half "R" or less.

O.B. Critical Velocity - 50% of shot is expected to be partial or full penetrations

Sources - AVIA 46 118

Last Updated on Thursday, 01 January 2009 21:21