Sealey HSS Cobalt Fully Ground Drill Bit Ø3.5mm Pack of 10 DB035CBFully ground HSS Cobalt drill bit manufactured to DIN 338. 5% Cobalt gives increased heat hardness which helps extend the life of the drill bit. 135 Split point is self centring which helps to reduce thrust and aids an easier penetration. Efficient clog free swarf clearance. Drills can be resharpened without affecting their performance. Available as a 19pc, 25pc or 170pc set or in packs of individual sizes. High density case for safe storage.