Sandflex&0174; BI-Metal, 3906 The virtually unbreakable and shatterproof Bi-metal blade with precision ground teeth for all kinds of metal sawing. With a blade back of strong, flexible spring steel and a tooth line in high-alloyed super high speed steel, this blade is guaranteed to keep its sharpness for a long time. Blade combines extreme cutting performance and wear resistance with a high degree of flexibility and is vastly superior to all-hard high speed blades or conventional, flexible blades. Packaging 2 carded blades. Material: Other Material.