|
| A unibit works but the best solution is a hole punch. I have several. I've had a Whitney Jensen #5 jr for about 50 years and there are Asian knockoffs on the market today. I've had a Whitney Jensen #15 for several decades. The punch has a point, just feel it into the center punch mark and squeeze the handles, a hole takes a second or less and is round. The #5 does 1/16 to 9/32. The 15 has a bigger opening and does small to 17/32" I have a couple others that do up to half an inch in 1/8 or thicker steel, not just thin sheetmetal. The little punches do fine in 1/16" steel and aluminum. There are shop sized turret punches that do a wide variety of hole sizes but are a lot more costly than the little ones I have.
135 degree split point bits should do better in thin sheetmetal than standard bits because they cut to the center while the standard bit doesn't. Last week Menards had a special on a kit of 135 degrees split point bits, 160 of them from 3/64 to 1/2" for $15 after the rebate. I haven't tested them yet.
Gerald J. | |
|
Why do drills make a triangle hole instead of round in thin sheetmetal
