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View Full Version : what should i look for when buying drill bits for car use


steveo3002
13-04-2008, 6:41 PM
id like to get some drill bits for diy jobs on the car , mostly drilling steel and maybe the odd attempt to remove snaped studs etc

what should i look for/avoid when buying drills...i want some that last well and cut good...or should i buy the cheapest i can find and replace often?

id also be intrested in some reverse drill bits...any ideas for a place to purchase those at a good price

Keith
13-04-2008, 6:46 PM
Taking more care when removing bolts/nuts and using plusgas or similar will help prevent them breaking.

I had to drill through a knackered seat runner, and the cheap drill bits repeatedly snapped and made the job much worse than it should of been, a decent drill bit was only beaten by the poor drill I was using. Buy cheap and you'll buy twice or 6 times in the case of my attempt at drilling

steveo3002
13-04-2008, 7:00 PM
fair enough..so whats a good one to look for , ive seen carbide, titainium and god knows what else

Keith
13-04-2008, 7:17 PM
I can't remember what I bought it was off the shelf in B&Q and was for steel only.

If you snap a bolt I think a tap & die kit is what you need

goldspanners
13-04-2008, 9:42 PM
i use dormer drill bits,they are pretty good and always sharpen up ok.
if you have snapped a bolt,drill a hole in the centre of the snapped bolt and get a set of "easy outs" turn the correct size into the hole you drilled and then turn itas if to unscrew,it tightens on to the bolt and should remove the remainder of the stud.
(all in theory of course,half the time it never works);)

scbk
13-04-2008, 9:43 PM
For small sizes I use the cheapest bits I can find as I always lose/break them. I drill quite a lot of 6mm and 8mm so have decent titex bits for these

vaio
13-04-2008, 10:10 PM
I use dormer drill bits, they are pretty good and always sharpen up ok.
if you have snapped a bolt, drill a hole in the centre of the snapped bolt and get a set of "easy outs" turn the correct size into the hole you drilled and then turn it as if to unscrew, it tightens on to the bolt and should remove the remainder of the stud.
(all in theory of course, half the time it never works);)

The dormer drills are indeed top quality. Not so sure about the “easy outs”, they work by being hard enough to cut into the bolt, hard steel is also brittle. The end result of this is that you end up with a stuck bolt, with a hole drilled down the middle but filled with a snapped “easy out” which is way too hard to drill again.

I’ve never had any luck with “easy outs” (unless you count the bad sort) but I have had success with left hand drill bits and the higher end stud extractors that are a sort of spline you hammer into a drilled hole before undoing it via a nut that slides over the spline. The other solution that has worked for me is to drill bigger and bigger holes until there is almost nothing left of the bolt and then collapse and pick out the remains with a pointy thing.

epninety
13-04-2008, 10:59 PM
FNorthern Tool sell left handed drill bit sets at a decent price. They are imperial sized, and not the best quality, but that's not too important as usually you want the drill to bite and shock loose the broken fasteners. That also means that even my cack handed sharpening keeps them usefu l:o
http://www.northerntooluk.com/

For my workshop drills I keep a set of Dormer TiN drills for 'good' holes (where size or finish is important) and a set of reasonable drills for general work. That way I always have a good sharp drill of the right size for 'tricky' jobs, and don't waste the good ones on nasty jobs where they are likely to get damaged.

edit : Found the drill bits at http://www.northerntooluk.com/products.asp?partno=150272E

goldspanners
13-04-2008, 11:02 PM
The dormer drills are indeed top quality. Not so sure about the “easy outs”, they work by being hard enough to cut into the bolt, hard steel is also brittle. The end result of this is that you end up with a stuck bolt, with a hole drilled down the middle but filled with a snapped “easy out” which is way too hard to drill again.

I’ve never had any luck with “easy outs” (unless you count the bad sort) but I have had success with left hand drill bits and the higher end stud extractors that are a sort of spline you hammer into a drilled hole before undoing it via a nut that slides over the spline. The other solution that has worked for me is to drill bigger and bigger holes until there is almost nothing left of the bolt and then collapse and pick out the remains with a pointy thing.

agree with you there,sometimes they work sometimes they dont,and sometimes they do snap making life almost impossible.
thats why i said in theory.;)

steveo3002
14-04-2008, 9:15 AM
yeah thanks guys , im aware of the problem with easy outs snapping in a abolt

i havent got anything to deal with at the moment but my old drill are blunt and id like some that are capable of drilling reasonbly hard stuff if i need to

viao what are those spine type ones you talk about? id be intrested in getting some just incase

Wig
14-04-2008, 3:59 PM
Buy a cheap set of HSS bits for now - everyday jobs, If you ever come across a tough nut/bolt or one that has corroded (exhaust) use a 6 pointed socket on it - these are usually the black impact sockets, they actually don't cost any more than normal sockets and are far superior when you are trying to remove a tough bolt.

This alone will not help to stop the bolt from snapping, if it's going to snap there's not a lot you can do about it, except using an oxy-acetylene torch to heat it red hot.

If you do snap a bolt, I suggest you start off with titanium HSS bits, and move onto cobalt if you have to. No need to buy the cobalt in advance, with next day delivery etc.

Left hand bits are expensive and I've never used them. But if and when you do snap a bolt the single process might be an attractive option to you and you can buy a set on that day, i.e. not in advance.

Some links for you
http://en.wikipedia.org/wiki/Drill_bit#Materials_for_bit_construction

http://www.toolstation.com/shop/DrillBits/CobaltDrillBits/d110/sd1230

epninety
14-04-2008, 5:06 PM
Left hand bits are expensive and I've never used them. But if and when you do snap a bolt the single process might be an attractive option to you and you can buy a set on that day, i.e. not in advance.

Mine were £20 plus vat for a set (up to 0.5") and paid for themselves the first time I needed them (broken stud in an engine block bodged by previous owner). Compares pretty well with a good quality set of ez-outs, and without the worry of breaking one in the hole.
If I had to start again in my tool collection, it would be one of the first things I'd buy - then again all my cars are old, rusty and muddy so I probably get more use out of them than most people.

Can do wonders for your social life too - all your mates will come round to borrow them :mad:

steveo3002
14-04-2008, 7:34 PM
hehe yeah my cars are all old and rusty too, i figure they something worth having for that sunday afternoon when you bust something

ive some okay deals on ebay usa ...work out ok with postage

vaio
14-04-2008, 11:43 PM
……..viao what are those spine type ones you talk about? id be interested in getting some just incase

Available from your local friendly snap-on van, a bargain at only £65 a set. Try your local motor factor for a cheaper set or go to ebay.com and get a set from the states

http://buy1.snapon.com/catalog/item.asp?P65=&tool=&item_ID=158&group_ID=1254&store=uk&dir=catalog

steveo3002
15-04-2008, 9:56 AM
thanks for the link....i'll put them on my want list lol , maybe keep an eye out next time im in usa, not sure id trust any old motor factor set as i wouldnt want one to snap off lol

LandyAndy
15-04-2008, 4:37 PM
The dormer drills are indeed top quality. Not so sure about the “easy outs”, they work by being hard enough to cut into the bolt, hard steel is also brittle. The end result of this is that you end up with a stuck bolt, with a hole drilled down the middle but filled with a snapped “easy out” which is way too hard to drill again.

I’ve never had any luck with “easy outs” (unless you count the bad sort) but I have had success with left hand drill bits and the higher end stud extractors that are a sort of spline you hammer into a drilled hole before undoing it via a nut that slides over the spline. The other solution that has worked for me is to drill bigger and bigger holes until there is almost nothing left of the bolt and then collapse and pick out the remains with a pointy thing.


:rotfl: This is the only thing that has worked for me. You can use magneticy things to extract the debris as well as pointy things;) .