To get that bolt out.
Theres a few options.
Sit the plate on an anvil and smack the bit of the bolt thats poking out hard with the hammer twice. Make sure its supported right under where the bolt threads into and is sitting nice and square. You dont want to crack the alloy.
Another trick would be to whack it in the oven and heat it up, try and crack the bolt while its hot.
Try grabbing whats left of the bolt in the vice and rotating the alloy plate. Take it easy.
If it wont work.
Grind the bolt down flush with the alloy, or even just so the top is flat/square and a little proud. Mark it carefully with a centre punch.
From there you have a few options.
Drill and give it a go with an ezy out.
Theres a couple of schools of thought here.
Dont go too big with the hole, if you do the metal distorts in the ally as you can put too much force into the steel and spread it. Id say in your case this is the one, the bolt is probably whitworth and they are not hard bolts.
Other school of thought it the bigger the ezy out the better as you can get more force.
Dont bust the ezy out, they are harder than a drill bit.
Try and get your hands on a small LH drill bit. No Poo, they do exist. When drilling into the bolt, in reverse, if the bit grabs in the steel it will wind the bolt out.
Or if you are set and square, you can drill a small pilot all the way down through the broken bolt and out the other side of the alloy plate, then with a bigger normal RH bit, drill back through from the other way and if that grabs it will screw the bolt out as well.
With reguard to any hole you drill being off centre. Start with a small pilot, then using that hole as the centre guide, drill oversize to what size the bolt was. But you will remove the threads. So in effect you are best to take it out to the size it needs to be to helicoil the hole. Or up to the next size bolt, most times you can get away with this.
Trying to drill it to the size that you need to tap a thread in the hole the same as the bolt that was in it, I have found is near on impossible. You need to be super accurate with the pilot hole marking and drilling, and as you drill all thats left in the hole is the threads of the bolt, they can grab, tear and send you off line hogging into the alloy.
The closer you get to the size of the bolt with the drill bit the more likely you are to run off center or it will show you up as being off center and due to the alloy being softer than bolt the drill will pull and hogg into the alloy and make a mess.
Its a pain in the butt situation but there is a way to save it.
