Rounded Allen key head

Re:

Just waiting for the liquid metal to arrive, should be here in the next couple of days. I'm guessing the bolt is alu, seems soft enough and had thought that the centre hole would help me to centralise if drilling out, but I only have a puny 18v cordless Makita. Do you reckon that would do it? Any tips. I guess use a small bit first and work upwards?

does a magnet attach to it? if not, then it is aluminium or stainless steel

a cordless drill should do it, use highest speed setting and start with small e.g. 3.0 mm - a too small drill bit is more likely to snap if you are holding the drill in your hands; obviously the frame will be held steady in a vice or workbench.

don't press hard on the drill, let the drill bit do the cutting.

the largest drill size will be the same as the bolt's minor diameter - i.e. the diameter of bolt without the threads - and you can then pick out the remaining threads using a scriber or other pointed instrument. Running a tap through will clean up anything that is left of the bolt threads.

02gf74":1ziml4bd said:

does a magnet attach to it? if not, then it is aluminium or stainless steel

a cordless drill should do it, use highest speed setting and start with small e.g. 3.0 mm - a too small drill bit is more likely to snap if you are holding the drill in your hands; obviously the frame will be held steady in a vice or workbench.

don't press hard on the drill, let the drill bit do the cutting.

the largest drill size will be the same as the bolt's minor diameter - i.e. the diameter of bolt without the threads - and you can then pick out the remaining threads using a scriber or other pointed instrument. Running a tap through will clean up anything that is left of the bolt threads.

Click to expand...

This is basically what i'd of said so agree with it 100% although not every one has a vice or work bench so getting too borrow a black and decker work mate or some one else to hold it steady should help make things easier ..

Or cut a groove length ways with a hacksaw or dremel into the end of a new bolt and run it through as a makeshift tap.

Re:

Is the bolt in question the only thing holding the pivot(?) on?

The reason I ask is that if you do decide to use an easy-out then drill the head off first. A drill bit fractionally smaller than the bolt minor diameter will be sufficient:

M4 minor diameter 3.14mm so 3mm drill
M5 minor diameter 4.02mm so 3.9mm (maybe a 4mm) drill.
M6 minor diameter 4.77mm so 4.6mm drill

If you leave the head on and then snap the easy out (much easier than you'd imagine) you'll be in a world of pain. At least with the head off you should be able to dismantle the part and then attack the stress relieved remains of the bolt at you hearts content. If the back of the hole is open (it goes right through) sometime the remains can be wound right out the back - often the friction from drilling can wind it through as well.

I have worked at several places where contract staff have been sacked for snapping easy outs without taking the heads off first. The time involved in sorting out the mess and subsequent delays soon add up.

Re:

Everyone here really knows their stuff. I'm just a mechanical idiot. Here's the suspect bolt...



And here's the bolt from the other side...



Here's a shot of the pivot from the side with bolt removed...



Hopefully that gives a clear idea of where I'm at. Progress this far is having sprayed Plusgas and leaving to soak.

Yes, I know I haven't got far, but have a doer upper of a house and a three year old, so this is something of a 'when I have the time' project. That and I really don't want to rush it and make an even worse job.

The current plan is to hammer a torx in with magic metal, let that cure and then see if I can budge it from there.

Bear, I'm getting the impression this might be a bad idea. However, I only have a puny drill and no workbench!

Thanks for all the advice everyone. It really is helpful, if slightly daunting!

Don't ponder on it too much as the more you worry the better the chance of it going wrong so you just need to have a little faith in your abilities and when you've done it you'll wonder why you didn't tackle it sooner ..

I dont think thats alloy but steel. You got bolt off on the other side so can use plus gas on it.

Support pivot and use a drift and hammer to smack the edges of the hole to reform the hexagonal shape, then hammer an allen key to clean up the recess. As it appears to be steel, it may be strong enough together with the plus gas soaking to undo. Id recommend buying a new good quality allen key for the great undoing, cheap ones loose the sharp edges as do good quality ones with use.

Might be a stupid question but is all the pressure off the pivot? One side out would twist the other. Simple job as you have access from both ends.

Sorry The History Man, what do you mean by 'all the pressure off the pivot'? :shock: