Ultra Stainless™ Phillips Pan Head Self Drilling Screw

Starts with 410 stainless and adds 2% molybdenum (the same ingedient in 316) Salt spray test - 500 hours. Ultra Stainless™ Marutex® screws are tempered and quenched; regular T-410 self drilling screws are case hardened.  The additional carbon in Marutex® provides hardness for betting drilling. Surface Hardness Approx. 50 HRC, Core Hardness Approx. 50 HRC, Carbon C 0.25,Silicon Si 0.48, Manganese Mn 0.49, Phosphorus P 0.018, Sulfur S 0.001, Nickel Ni 0.48, Chrome Cr 13.42, Moly Mo 1.96,Copper Cu 0.47