3件組埋頭鑽組 1/4"、3/8"、1/2" 鉸刀 3刃 鈷 82° Drill Hog USA

The three-flute design really does cut faster than the old single-flute countersink I had, and the chips clear out instead of clogging. Cobalt steel held a sharp edge through a whole afternoon of deburring holes in mild steel. The 1/4" shank fits my drill chuck without any wobble.

Used these on hardened steel plate and they cut clean chamfers without chattering. The 82° angle matches my existing countersunk screws perfectly, and the 1/4" shank fits my cordless drill with no wobble.

The tri-flute design really does cut faster than the old two-flute set I had, and it leaves a much cleaner chamfer on aluminum. Ran the 1/2" one through a dozen holes in mild steel and it still bites like new. Solid set for the price.