And hot-rolled armor protection steel BP500 of Baosteel and Wuhan Iron and Steel Co.

Relying on its own equipment level and technical strength, Baosteel took the lead in successfully developing BP series high-performance armor protection steel with thickness ranging from 2 to 12 mm. This product uses hot rolled coil as substrate for heat treatment, which has excellent bullet resistance, strong destructive impact resistance, uniform and stable performance, and good shape and surface quality.  

This series of products is suitable for cash trucks, armored personnel carriers, escort vehicles, VIP vehicles, security doors, bank counter protection boards, safes, shields, helmets, etc. The hardness of BP series protective steel is high, and machining is relatively difficult. Drilling should generally use high-speed steel or ceramic hard alloy steel bit. 

To ensure the high efficiency and accuracy of batch drilling operations, it is recommended to use high-speed alloy steel (HSS-E) or cobalt-containing high-speed alloy steel (HSSCo) drill bits.  

When milling, the workpiece should be clamped. It is recommended to use a wide-moment milling cutter. The material of the face milling cutter can be cemented carbide coating, ceramic alloy, etc., and the end milling cutter can be cemented carbide, cobalt-containing high-speed alloy steel, etc. The combined milling head should be avoided as far as possible. The cutting width of the face milling should be 75%-80% of the diameter of the milling head.