高速鋼錐形鑽頭

Bought these to enlarge existing holes in my metal brackets and the conical shape really does make for a smooth entry. The high-speed steel holds up fine, no dulling after a full afternoon of drilling.

Drilled through a dozen holes in sheet metal this afternoon and the conical shape really does keep the bit from wandering. Clean entry every time, and the high-speed steel held its edge through the whole job. Glad I picked up a set.

I’ve used these on aluminum and mild steel, and the conical shape makes a huge difference—no walking or squealing like with standard bits. The cut stays smooth even after a dozen holes, and they’re still sharp. Definitely worth the upgrade for anyone doing precise work.