Imperial Blades 3MMTV - 3 Blade Variety Pack Titanium Bi-Metal Universal Oscillating Blades (MMT330, MMT335 & MMT340) The variety three pack is titanium coated to give the blades longer life. These are the most popular blades we sell. Bi-Metal blades are for: wood, metal and PVC. Our highest quality Titanium coated high speed steel blade is specifically designed for various applications. Popular uses for this blade: Cutting through nail-laden wood, deck screws, sheet metal, etc. 18 TPI (Teeth per inch).