This strength protected the life of a Special Forces advisor in El Salvador when a Hartsfield knife stopped a 7.62×51mm NATO rifle bullet fired by a guerrilla. Hartsfield's blades were zero-ground, meaning there is no secondary bevel edge on the knife, which allows the knife to cut without parasitic drag.
In a perilous situation in El Salvador, the exceptional strength of Hartsfield's knife proved instrumental in saving the life of a Special Forces advisor. The unique design, featuring a zero-ground bevel, allowed the blade to cut through with minimal resistance, ultimately thwarting the guerrilla's attack.