5 replies to this topic

[Kam]

That kids game of trying to fit a square peg in a round hole comes to mind

Need to drill a couple of holes in a metal door (non car!) thats about 2mm thick to house coach bolts.

Whats the usual way to do this?

Drill hole more or less thread size and bang bolt in
Or drill hole and somehow cut out square

If its the second one how do you cut it?

Apologies for silly question but I've never come across fitting these before!

[cambiker71]

How many? If its just a couple then drill out to thread size and use a small square file to make some corners to make it square, if it's quite a few more then i'd guess there is some sort of tool to do the job, but not sure to be honest.

[Kam]

I think in total when I'm eventaully finished it'll be about 8 holes?

Edited by Kam, 09 January 2009 - 08:54 PM.

[Bungle]

you can drill square holes in wood but don't know of a tool for metal

[Shifty]

There are square punch tools for sheet metal work, however for 2mm thick steel a hydraulic punch would be needed.

You may be able to hire one??

However your best option would be to drill a hole the same diameter as the sq part of the bolt(ie if the square part is 10mm x 10mm use a 10mm drill) and then use a file to square off the corners.

If you've got a decent file it won't take long to do.

[Udo]

Use a smaller drill bit ie 1 - 2mm and chain drill around the square aim a little smaller put bolt in place then hit with hammer to locate the square