drillbit question

[cacardon]

good day all, I have a quick question. I am needing a 12.5mm bit for a pen kit. I don't have one I could drive and get one, but the language barrier is tough to over come here. Will a 1/2 work? I know its .2mm bigger but will that make that much of a difference?
as always
thank you and Semper Fi

 

[Edgar]

Another way to look at it is that the best English equivalent to 12.5 mm is a 0.492"' bit, so a 1/2"' bit is .008" larger than ideal.

It will likely work ok, but to be sure, you should drill a hole into some scrap wood with the 1/2" bit and test fit your tubes befor drilling a real blank.

 

[NittanyLion]

I use a 1/2 bit in place of 12.5mm bits only because I cannot find a high quality 12.5mm bit. Just make sure your drill press/lathe has no drift in it and it drills true. I also use epoxy for gluing my tubes. I would not want to use CA or any other glue with the extra room. Hope this helps!

 

[mutley]

31/64 is just under, 0.484 vs .492 or 12.3 vs 12.5. You can probably make that work quite easily depending on the glue used to set the tube.

 

[randyrls]

Charles; Try the smaller bit first. Try to fit the tube and see if it is large enough. I always do this experiment to "try" the fit before drilling a bunch of blanks. There are several drill bit charts in the Library and on the net that have decimal size comparisons.