Drilling pilot holes in bolts for removal

[JBR]

I have some window handles in the bathroom which are quite loose (the handles but not the mountings). They've been like that since we moved in (ten years), but I've now decided I want to replace them. The problem is that, apart from one, all the fixing bolts have pozidrive screw heads which have (before we moved in, I should add!) been worn virtually smooth by camming out and I cannot remove them.

For that reason, I think I shall have to drill pilot holes and get some screw extractors to get them out. As I have never used these before, the question I need answering is how to drill the pilot holes - quick drill rotation or slow? I've heard both options. Also, is it necessary to use a lubricant (I have WD40)?

Another option is to 'drill the bolts out'. I take it that this is to remove the head, and allow removal of the handle, but wouldn't that leave the rest of the bolt where it is? If so, I'd still have the same problem when it comes to fitting new handles with new bolts.

 

[bernardgreen]

If the handles are going to be scrapped then using a hacksaw or ( much faster ) an angle grinder to cut a slot across the head of the bolt so you can use a flat bladed screwdriver to turn the bolt.

 

[Burnerman]

You could well find these screws pretty hard, unfortunately but by all means give the drill a go.....small, new bit, high speed with lube.
If you do get the heads off, hopefully the screw shank will still be there - unscrew that with mole grips.
You may well find Bernard's idea the most successful.
John

 

[JBR]

If the handles are going to be scrapped then using a hacksaw or ( much faster ) an angle grinder to cut a slot across the head of the bolt so you can use a flat bladed screwdriver to turn the bolt.

That would be difficult, I'm afraid. The bolts are well recessed within the handle assembly, but thanks for your suggestion. I did try drilling a slot using a Dremel-type drill, but without much success. As Burnerman said, they appear to be very hard.

 

[JBR]

You could well find these screws pretty hard, unfortunately but by all means give the drill a go.....small, new bit, high speed with lube.
If you do get the heads off, hopefully the screw shank will still be there - unscrew that with mole grips.
John

Yes, as I said above, the bolts do seem to be very hard. Despite that, the previous owner (Rodger the Bodger) has obviously had no trouble in eroding the cross-head so there's nothing really there any more for a screwdriver to grip.
I think that drilling a pilot hole is going to be my only hope, other than new windows; they are actually quite narrow fanlights so, if necessary, they shouldn't cost a great deal.
I'll get some new metal drill bits (the ones I have now are all pretty old and blunt) and give it a go.
So, high speed with lubrication. OK. I only have WD40 but, if that's not the best, I can get something else.

 

[Burnerman]

Is there any mileage in using an angle grinder to grind the handle down, complete with the screw head?
John

 

[alan333]

Along the same lines as Burnerman - hack away at the plastic handle somehow, until you can get mole grips or similar onto the bolt heads.

 

[joe-90]

You'll almost certainly snap your drill bit. The only bit that will drill hardened steel is a cobalt one, but will still snap. You are better off trying extractors that dig into the remaining screw head.

 

[JBR]

Is there any mileage in using an angle grinder to grind the handle down, complete with the screw head?
John

I'm afraid I haven't got an angle grinder, but I suppose I could hire one if necessary.

Along the same lines as Burnerman - hack away at the plastic handle somehow, until you can get mole grips or similar onto the bolt heads.

I wish it were plastic! Both the handle and its mounting is metal, presumably steel.

It looks like I'll have to try the drill, when I get some new drill bits and when I have the time. Fortunately, it isn't urgent. If I can drill some pilot holes, I'll invest in some extractors too (the ones where you drill anticlockwise).

 

[Burnerman]

Only my opinion mate but I'd scrap the idea of drills and 'easy outs' - and head for the grinder. The catches may be steel may be alloy, but they'll still grind away if access is ok.
John

 

[pauldelahaye]

In no way the highest quality tool, but for £2.99 at Lidl, they have got us out of trouble a couple of times at work when we have rounded out some hex screws.

Problem is I don't know if they are still available in Lidl as the offers always change.

http://www.offerscheck.co.uk/powerfix-screw-bolt-remover-set/lidl/2014/kw-31/84773

 

[JBR]

I found this:
http://www.screwfix.com/p/screw-extractor-5-piece-set/18643

 

[Burnerman]

That's what we call 'easy outs'......theoretically good, I find them useless but by all means give them a go.
You'll be pushed to drill down a hard screw enough to get them in.
Seriously......get rid of the screw head, one way or another, and pull the catch away. With a set of mole grips, the remaining screw shank will wind out ok, as the pressure has been released.
John

 

[joe-90]

Those extractors are useless.

 

[phatboy]

Only issue with the grinder is the hot bits of handle that come off will hit the (probably) PVC windows, causing small burns.