سلاسل مثاقب الكربيد – Geppetto

Internal or external coolant?

On internal-coolant carbide drills (D32, D52, D82, DT50, DT80) coolant reaches the tip through channels in the tool. It cools the cutting zone and pushes chips out of the flutes. For 5xD and deeper holes, long-chipping materials such as stainless steel, and high-feed production, internal coolant is the first choice – provided the machine has through-spindle coolant.

If the machine has no through-spindle coolant, use external-coolant D30 and D50. Aim nozzles at the tip and use peck cycles in deep holes to avoid chip packing.

Coating and material choice

Standard series use AlTiN coating. AlTiN offers high heat resistance and works well in steel, alloy steel, stainless steel and cast iron. For Kevlar and composites, sharp uncoated or AlCrN-coated DK and DSF series are preferred. For aluminium and non-ferrous metals, uncoated or suitably coated special drills can be made.

What to watch when choosing a carbide drill

Divide hole depth by diameter: up to 3xD a short drill is stiffer and gives better hole quality. Do not choose a longer drill than needed. In deep holes, a short pilot of the same diameter extends life. Use a low-runout hydraulic or shrink holder; runout is the carbide drill’s worst enemy. Start from catalogue cutting data and use our calculator for speed and feed. Worn carbide drills can be reground to original geometry with our regrinding service.