Bolt extractors or not?

**Jpdv** · 3rd July 2022, 05:33 PM

Hmmm. My engine undershield has (of course) 1 bolt which is seized. 13mm. I cranked at it with a breaker bar after a good WD40 soak, and it rounded the bolt. Soooo. Option 1 is drive to a workshop and ask them to free it. Option 2 is one of those bolt extractor sets (eg Kinchrome) which have a hardened toothed grip socket... They look quite a good idea, but I've never used one before. Option 3 is someone here having a better idea. I don't want to make it worse by incompetent amateur butchery, but wonder if these bolt extractors work, or are snake oil to be avoided...

Grateful for all (helpful/constructive) replies!

Thanks.

**FisherX** · 4th July 2022, 08:40 AM

A bit of heat will be your friend here. Do you have a blow torch or a heat gun? If you've rounded the head of the bolt you can usually hammer on a socket the next size down.

**josh.huber** · 4th July 2022, 08:43 AM

Map gas gun kit from supercheap or bunnings, so many uses!!

i have an irwin set of those extractors, i dont use them often, but when i do, they work well enough, they are not miracle workers but. if the threads are held so tight that the bolt rounded off they often wont be able,

a workshop may be able to weld a nut on for you.

**p38arover** · 4th July 2022, 08:44 AM

Flank drive sockets, e.g., Metrinch, work well on rounded off hex heads.

**POD** · 4th July 2022, 09:03 AM

A seized thread and a rounded head are two different (albeit related) problems. Don't risk snapping the head off by putting a tool on it with a great grip, to leave yourself with a seized thread and no head, then you are in drill territory which is a right pain. Get some heat and penetrating oil into the thread.
A bloke I knew once taught me an effective way to get a lot of heat into a seized bolt: using a stick welder, soak a couple of electrodes in water first. With the welder switched off, hold the tip of the electrode firmly on the head of the bolt, then switch the welder on (easier to have someone else flick the switch). The electrode will glow red hot after a few seconds, switch off and repeat with a fresh electrode. After a few electrodes, the bolt will be very hot. This generally frees seized threads. Take the usual precautions for welding on a vehicle; i.e. disconnect battery etc.

**Jpdv** · 4th July 2022, 05:00 PM

Ah well,

Blowtorch heat, smacked with 'attitude adjusting tool', bolt extractor head on it, cheesed the extractor, further rounded the bolt. Won't come out. Luckily it's accessible and in a chassis member. I'm going to cut the bloody head off and get everything off the area, then drill out the stump. I'll replace it with another bolt IDC. Annoying, but at least it's not in a critical/delicate piece of expensive technology.

**Discosux** · 31st July 2022, 07:18 PM

Originally Posted by Jpdv

Ah well,

Blowtorch heat, smacked with 'attitude adjusting tool', bolt extractor head on it, cheesed the extractor, further rounded the bolt. Won't come out. Luckily it's accessible and in a chassis member. I'm going to cut the bloody head off and get everything off the area, then drill out the stump. I'll replace it with another bolt IDC. Annoying, but at least it's not in a critical/delicate piece of expensive technology.

Cobolt drills are the best. get a brand new one.

**Rick1970** · 4th August 2022, 06:48 PM

If thread is seized, gas blowtorch is usually not enough.....oxy territory.....
If it was me, I'd weld nut to the head of the bolt before cutting it off..... good heat and the expansion/shrinking 'usually' helps (few love hits while it's still hot also helps).
Can always do the fun cut/drill routine if that fails.

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