That’s what the old boys used to do with a countersink bit to stop the chatter marks.

Was shown that in the early 50's at Tech College

Roy

Even with the cloth I would not hold the sheet metal with my hands as shown in the video. You only get one pair of hands and it's better not to rip them to shreds on a drilling machine.

Doug

Good trick. Also, if you are doing a lot of sheetie work, you can sharpen your drill bit as below. These days I just use a step drill for the thin stuff.

Hello to you all.

just watched that video…I would not recommend that way at all…that’s a surefire way of loosing a finger or life changing cut to hand….what an idiot for putting that online.

when I worked in engineering…the way to drill the sheet metal on a bench drill was to have a bit of plywood and clamp workpiece to it… then drill hole . Safely!

this worked on bench drills …jig borer tables….even lathe faceplates …for thin disks.

the good idea was when you had drill through metal..you had wood so you knew when you had drilled through…just deburred afterwards.

Edited By Steve Purkiss on 24/04/2022 08:30:33

Yes it’s old hat that video, but not if you havnt had the tip. It works!

but why

does it take such a long video?

the wood block is clamped down, why not clamp the work at the same time? He says don’t hold the piece, then goes and does it!

I have some special sheet metal drills designed to drill unsupported sheet alloy such as aircraft skins. They drill a perfectly round hole because there is no relief on the outside like normal twist drills which tend to leave triangular lobed holes.

If possible for flat sheets, the sandwich method is best to reduce distortion.

I watched his excellent video at 1.25 normal speed.