303 HST stainless steel bar is engineered to optimize machine performance in high volume, screw machines. It also delivers superior surface finish and product consistency. Traditional RAM 303 product is treated to enhance machinability when using carbide-tipped tooling at high cutting speeds. 303 HST, like RAM 303, is also alloy treated. However, the highly controlled production techniques for 303 HST produce a finished product with optimized mechanical properties. This provides optimum productivity and quality when using high-speed steel tooling at lower cutting speeds. As a result 303 HST is the most versatile premium machining product available. 303 HST is available in cold-drawn round bar and hex bar from 3/16" through 1" in diameter. It is chamfered and boxed. Round bar is centerless ground to 1/4 of standard tolerance.

303 HST should be heated to 1900°F minimum, and water quenched or rapidly cooled by other means. 303 HST cannot be hardened by heat treatment. 303 HST is not recommended for applications requiring welding. Its high sulfur content increases the likelihood of weld solidification cracking. When welding is necessary, AWS E312 filler metal may be considered. An alternative alloy for parts requiring welding is RAM 304L.