5件組埋頭鑽套組 1/4、3/8、1/2、5/8、3/4 鉸刀 3刃 鈷鑽頭 Hog 美國

Bought these mainly for the 1/4" and 3/8" sizes to deburr holes in aluminum brackets, and the three-flute grind leaves a much cleaner chamfer than my old single-flute bit. The cobalt holds an edge well even after a few dozen holes.

Used the 3/4" on some mild steel plate and it cut way cleaner than the cheap set I had before. The three flutes clear chips fast, no chatter at all. Sizes are stamped clearly too, which matters once they're mixed in the drawer.

Bought these to chamfer the holes on a steel plate project and the 82-degree flutes cut clean without chattering. The 1/4" got a lot of use on aluminum too and still bites hard. Nice to have all five sizes in one set instead of hunting them down separately.