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Drilling hole in HT bolt...help!
Posted: Thu Jan 10, 2013 9:52 am
by Nick Allen
We need to drill holes in some high-tensile bolts to take a split pin. One of the syndicate had a go, but so far has only managed to blunt some drills! Any advice on techniques/tools would be appreciated...
Re: Drilling hole in HT bolt...help!
Posted: Thu Jan 10, 2013 10:21 am
by Ken Fern
Hello Nick
Best thing is the drilling jig sold by LAS part No MT001 and set it up in a pillar drill, with a good 1/16" drill you will have no problems, just take it nice and steady to save snapping the drill. Have used mine for many years no problems. Just a thought the LAS one is for UNF threads but a friend made me a similar one with BA, BSF threads as well.
Hope this helps
Ken
Re: Drilling hole in HT bolt...help!
Posted: Thu Jan 10, 2013 10:50 am
by Nick Allen
Thanks, Ken. Much appreciated. Nick
Re: Drilling hole in HT bolt...help!
Posted: Sun Apr 14, 2013 5:49 pm
by dangerous pete
Nick,
I had some done by spark erosion, at an engineers on our local industrial estate. Not vey expensive.
Pete.
Re: Drilling hole in HT bolt...help!
Posted: Mon Apr 15, 2013 1:30 pm
by Ian Law
Slowing the drilling speed right down seems to help with hard materials/slightly blunt drills.
There is a sweet "spot"/speed at which the drill appears to bite more willingly - but you may well already know this.
Ian
Re: Drilling hole in HT bolt...help!
Posted: Mon Apr 15, 2013 4:59 pm
by Trevor Harvey
Use a centre drill first to stop the drill wandering, (unless you are already, in which case I apologise)
Use cutting compound (Rocol or similar) Run drill at ~500rpm & take it slowly, don't push too hard.
Re: Drilling hole in HT bolt...help!
Posted: Tue Apr 16, 2013 12:15 am
by Bill McCarthy
Put a nut on the bolt first in order to get the hole central and in the right place. Drill a pilot hole to make life easier.