Whiteside SC91V 超硬ソリッドカーバイド グラスファイバールータービット プランジポイント付き

That diamond pattern really does grind through fiberglass cleanly instead of catching and fraying like a standard bit would. I was able to plunge straight into the material without any chipping around the entry hole.

The vee-point tip is a lifesaver for starting clean holes in fiberglass without skittering across the surface. It takes a bit of patience, but the grinding action beats the chattering of a standard bit, and the edge is holding up well after a dozen plunge cuts.

The vee-point tip plunges into the panel cleanly, no chipping or wandering at the start. The diamond pattern chews through fiberglass without that nasty grab-and-shatter feeling I got from standard bits.