Undoing seized nuts and bolts

[PeterG]

Undoing seized bolts on a restoration can be a challenge, but there are a number of ways to do it.

WD40 for a few hours and trying to turn with a decent spanner is the best way.
If that doesn't work, heating the body of the unit with a blow torch to allow the metal around the bolt to expand is always worth a try - tapping the body of the unit with a hammer as you turn the bolt can also help loosen any corrosion - it is also worth doing half a turn, turning back the other way and going forward and reverse a few times slowly and steadily which helps.

If the head snaps off, you have a number of options - there's drilling out and re-tapping, but another way is to weld a nut on to the end of a snapped thread effectively making a new bolt head. I decided to try this first in this particular case pictured, which has to be about the most stubborn bolt I've ever come across. It came out in the end. It was embedded in cast aluminium.

Just in case these techniques are of any use to anyone. There's always a way.

[FrontSideBus]

Drilling a hole into a broken fastener and then hammering a torx bit into it also works wonders... I don't think I've ever used my torx set on an actual torx bolt!

[Cobster]

Sawcut a slot into snapped off bolts and screws for a flatblade driver.

[PeterG]

Drilling a hole into a broken fastener and then hammering a torx bit into it also works wonders... I don't think I've ever used my torx set on an actual torx bolt!

Thats an interesting suggestion - wouldn't mind seeing pictures of such a technique - I'm always up for learning summat new

[PeterG]

Sawcut a slot into snapped off bolts and screws for a flatblade driver.

Another excellent idea!

[FrontSideBus]

That works well if there is enough room to get a file or a saw in but can be tedious when space is tight.
One thing should be noted about the nut welding trick, the extreme heat does help with boiling the shit out of the threads but can also sometimes make things go very hard indeed which might lead to problems down the line.
Say for example if they bolt has snapped off below the surface and the weld keeps breaking, you might have to go at it with a carbide burr and a die grinder as normal HSS drills won't touch it! Lol.

[Oliver]

I've got a sign light where the 25mm steel pole is stuck inside the bracket and it's cut flush. No clue how I'm gonna get it out. The 2 grub screws had to be drilled out and it went through loads of drill bits and they were glowing red. The grub screws are pretty much drilled out but the pole is still stuck in. Any ideas how I can remove it?

All I can think is somehow heat it up and hopefully it drops out but I doubt it tbh.

[FrontSideBus]

What might work, and this is good for removing outer roller bearing races in blind holes, is to run a bead of mig weld around the inside. When it cools, it contracts and said roller bearing race just drops out!

*edit* just read it was 25mm, forget that then. For some reason I was thinking much larger like on a street lantern...

[Ash]

If you have a drill press try to drill an end to end cut in the part of the pole (making it from an O to a C sorta), then bend it inwards or repeat in a 2nd location to split it to 2 parts

[Oliver]

Good idea. It's made of 1970s steel and it's tough as nails! Even the little grub screws burned out loads of drill bits.