Ballistic Steel

• We cut certified armor plate to your dimensions by waterjet.
• Automotive Armor Manufacturing is a fabricator, not a steel distributor. We purchase certified ballistic plate to the published military specifications and cut it down to your dimensions - then, if you need it, build it into a finished armor system in the same facility.
• That matters if you would otherwise source plate from one vendor and find a fabricator separately. We supply MIL-A-12560 (MIL-DTL-12560K), MIL-DTL-46100E and MIL-DTL-32332 cut to print, as a GSA contract holder (GS-07F-062DA).

Request a quote on cut-to-size ballistic steel - send us your print, grade and quantity.

• Waterjet is cold cutting - no heat-affected zone.
• How ballistic steel is cut changes what you receive. Hardened armor plate gets its performance from a controlled heat treatment, and that heat treatment can be undone at the cut edge.
• Plasma and laser cutting are thermal processes. They melt through the plate, and in doing so they locally re-heat the steel either side of the kerf. That band - the heat-affected zone - is tempered and softened relative to the parent plate. On a high-hardness or ultra-high-hardness grade, where the whole point of the material is hardness, a softened edge is a real reduction in the property you specified and paid for.
• Abrasive waterjet is a cold process. It cuts by erosion rather than melting, so there is no heat-affected zone and no edge tempering. The plate you receive holds its certified hardness right up to the cut line, and the edge is ready for welding or assembly without having to machine damaged material away.
• This is why we cut every grade below by waterjet rather than plasma or laser.

• MIL-A-12560 / MIL-DTL-12560K Ballistic Steel
• The long-standing U.S. military specification for homogeneous armor plate, widely referenced by its superseded MIL-A-12560 designation as well as the current MIL-DTL-12560K. It is the general-purpose structural armor grade: tough, weldable, and specified across combat vehicle hulls, vaults, doorways and hardened structures.
• Its defining characteristic is that hardness is thickness-dependent - the specification sets a different Brinell range for each thickness band, because hardness is traded against toughness as plate gets thicker. A single hardness number quoted for this grade without a thickness is meaningless.

• MIL-DTL-46100E Ballistic Steel
• A quenched and tempered high-hardness plate for lightweight armor applications, intended where resistance to ball and armor-piercing ammunition is required along with multiple-hit capability. Commonly referred to as 500 BHN class armor.
• Compared with MIL-A-12560, it buys protection at lower weight - the reason it is specified for appliqué and vehicle work where mass is constrained, including vehicle armor kits.

• MIL-DTL-32332 Ballistic Steel
• The newest and hardest of the three, at roughly 600 BHN nominal. MIL-DTL-32332 exists to deliver equivalent or greater protection than lower-hardness armor in a thinner, lighter plate - which is why the specification tops out at 0.630". It is not produced in heavy sections, and that is by design rather than a limitation.
• It is specified for light tactical vehicles and weight-critical applications facing high-velocity and armor-piercing threats, where every pound of armor is a pound taken from payload or mobility.

• AR500 Ballistic Steel - rated to NIJ Level III (RF1) at 1/4"
• AR500 comes up constantly in comparison against the military grades, and the distinction is worth being precise about, because it is not a difference of quality - it is a difference of what the number guarantees.
• AR500 is a commercial abrasion-resistant grade. The "500" refers to a nominal Brinell hardness of about 500, and the material was developed for wear life - chutes, liners, buckets, cutting edges. It is sold to a hardness target, not to a ballistic acceptance standard, and there is no requirement for any given plate to have been ballistically tested.
• MIL-A-12560, MIL-DTL-46100E and MIL-DTL-32332 are ballistic specifications. Plate supplied to them is produced, tested and certified against ballistic acceptance criteria written into the specification, with documentation to match.
• A.A.M.'s AR500 is rated to NIJ Level III (RF1) at 1/4". That is the practical distinction in one line: the AR500 grade carries no ballistic obligation, but the plate we supply has a protection rating attached to it at a stated thickness. It is a real option for rifle-threat protection where a military specification is not a contractual requirement. See ballistic ratings for what that level covers.

For a range target or a wear application, AR500 is often the sensible and more economical choice. If you are writing to a contract, an RFP or a government specification, the certification is the point - and AR500 cannot satisfy a MIL-spec line item regardless of how hard it measures. If you are unsure which your requirement calls for, send us the spec and we will tell you.