Easy way of finding centre to drill a hole in round stock

Easy way of finding centre to drill a hole in round stock. I know that a lot of blokes (and gals) know this trick, but I'm sure that there's a lot that don't and it's always good to refresh an idea now and again. I know that true machinists have better and more accurate ways to find centre, but for your average backyard metal basher this is a quick and easy method.

Edited By Jim Dobson 1 on 09/05/2019 04:19:12

Nice, provided the diameter of the stock permits. The true machinist uses a method appropriate to the needs of the job, and this would be quite accurate enough for many applications. Another method is to pop an end mill in the chuck, use the lever quill feed to just kiss the top of the stock, and machine a very small flat, not much more than a line, across the surface. Then replace with a centre drill, position that in the middle of the flat, and you're away.

A statement of the obvious I suppose, but I use this method to set lathe tool height too.

Yes, I use this method to set tool height as well, but had never twigged to use it this way - doh!

John, what diameters would not permit this method? I know it becomes less accurate the larger the diameter but I have not found a diameter it won't work on.

Jason, I was thinking of a bar that is too small to project above the vice jaws when held as shown. Or too short to be stuck out the side of the vice or chuck.

Ha ha, the purists would say he should be using a spotting, not a centre, drill. I would likely use a centre drill.

John there is nothing to stop the bar being supported on packing/parallels, I regularly use the method do drill 0.8mm holes in 1/8" and 3/32" pivot pins to take 1/32" split pins and have even done it on 1/16" stock for 0.5mm split pins.

J