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Sharpening carbide drill bit

Got a call out yesterday to a mate with a stuck locking wheel nut stopping him changing a flat tyre. Looks like the gorillas at the tyre fitting place he'd last been to had torqued everything up to several hundred foot lbs. The first wheel nut key had just snapped in half trying to get it out and the £25 replacement from Vauxhall was having no more luck. The AA had been round, tried every tool in the van and failed miserably and then in desperation they'd hammered a socket onto it without stopping to think that would only spin because the bolt had a rotating collar on it to prevent pikey car wheel thieves doing just that. So we now had a stuck bolt plus a socket stuck on it filling the hole in the wheel and preventing any other tool getting anywhere near the job. Nothing would persuade the socket to come back off. I even tried welding a hook to it and levering that with a

6ft crowbar but it eventually just snapped the hook off.

To add to the woes the bolt was hardened steel. I managed to drill a pilot hole through it with my only carbide drill, a 5mm one, but trying to open that up with bigger HSS bits was getting nowhere. Carbide porting burs were just being blunted without making much progress and after scrapping a £30 one I gave up on that too. I tried making more pilot holes around the original one with the carbide drill but the odd shaped end to the bolt where the key fits meant I was trying to drill into an interrupted shape rather than solid metal and in the end I snapped a flute off the end of the drill. Finally I managed to weld into a hole about 1 inch deep through the inside of the nut to tack it to the rotating collar with my MIG and got the socket and collar off. Next step was to try and weld a nut to the remains of the bolt but my little MIG didn't have the grunt to really stick the two together. In the end I hammered another socket onto what was left and it came out :) Only took 5 hours.

So I'm left with a buggered carbide drill bit which used to come in really handy for pilot holes in tough jobs. It's always much easier opening up a starter hole than trying to drill from scratch with HSS in nasty materials. A new one is only about a tenner but I'm hoping to get it reground. However it would need shortening by about 5mm due to the missing flute on one side. I reckon I can clean it up somewhere nearer on my diamond wheel but I'm crap at hand sharpening drills and they always pull to one side after I'm done with them.

So does anyone have a diamond wheel drill sharpener who could finish it off for me or know of a place who would do it without it costing as much as a new bit?

Second question. I was really struggling to weld things as big as a socket or a 19mm nut to a big bolt with my little MIG. Everything was glowing yellow hot inside the job but not actually sticking together. Maybe chrome plated sockets and zinc coated nuts are not ideal things to weld together but there was little I could do about that. In the workshop it seems to cope with smaller stuff like welding a 13mm nut to a stuck 8mm stud which what I mainly use it for.

I think I either need a bigger MIG or a stick welder for stuff as big as wheel bolts or should I still have been able to do it if the materials had been nicer to weld to? It didn't need any fancy welding - just enough adhesion to stick the two things together well enough to get the bolt out with a socket bar. Comments/suggestions?

Reply to
Dave Baker
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from "Dave Baker"

Sorry I haven't got any real answers for you Dave but I had a similar problem last year which took 4 days to sort! After failing to get the locking nut off on Saturday afternoon the AA recovered me 135miles, arranged for another operator to come out on the Monday and set up a free rental car. This second AA man told me that 40% of his time was spent trying to remove locking nuts!

The idea of soft locking nuts with only 3mm depth of security "shape" where the hardened socket simply rips it off seems so stupid that when my garage eventually got the thing off I told him not to replace them!

JG

Reply to
JG

You're not wrong. The security shape is just plain f***in stupid on these Vauxhall ones. There's even a touch of relief angle on the key too so it just tries to cam out as you apply torque to it and it is indeed only about

3mm deep. Hard bolts and soft key on this though so the entire security shape on the key had ripped off on the first one. The second one just cammed out when I tried it on the bolts on the other wheels so I didn't even bother any further. A garage can do it with an impact gun and then my mate will change them all for std bolts or better aftermarket locking ones.

If I can't get a bolt out with these keys with 30 years experience of working on cars I don't rate most owners chances very high if they get a flat out in the middle of nowhere. The ones I've had in the past with three hardened pins work better and those on my Focus cause me no problems. The Vauxhall ones just have a sort of cloverleaf shape made out of metal with only about 1mm wall thickness and 3mm depth. Such a stupid design it pretty much beggars belief.

Reply to
Dave Baker

Conversely, the locking nuts on my Discovery seem to be harder than the socket, and I've gone through 2 special unlocking sockets in 5 years, as the 'pin' inside these appears to be mild steel.

I keep a spare handy now as these are special order patterns and not stocked.

Peter

Reply to
Peter Neill

I don't like them and my current '98 Vectra has even got one wheel buggered where a previous garage removed one with a die grinder. But if the bolts are done up to the correct torque (81 lb ft in my case), they work perfectly.

The only thing that is achieved by the kwikfit gorillas and their impact wrenches is to increase the chance that a bolt or stud is going to break one day, followed by the others and lead to deaths. There is a torque wrench with

17mm socket in the back of my car. It is there to be used!

Mark Rand RTFM

Reply to
Mark Rand

Hi Dave As no one else has offered help, I shall step in. I note you are only

5 miles from Bert's old shop, in which direction? E-mail me your address and I'll pick up your drill bit, will a four facet grind do? T.W.
Reply to
the wizard

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