Busch® Carbide Twist Drills made of the finest grain carbide are used as part of the special tools for pave' setting. Due to its short working part, the twist drill 4205S is an easy guiding tool to produce precise, uniform holes in very narrow spaces as necessary for tight pave' settings. When working on jewelry materials which are difficult to cut, such as platinum, titanium, steel, numerous holes can be drilled with constant precision after centering using this tool. Recommended speed is 3,000 - 5.000rpm. Made in Germany.