Rounded bolt removal

[chazwozza]

Hi folks, one of the seat bolts on my MX5 is extremely tight. I have tried the correct size socket to remove but it is starting to round. Any ideas for getting it out?

Thanks!

[guards red]

These will take anything out...

https://www.irwin.com/tools/screw-bolt-extractors/...

Ignore the bad review, I have used these many times on some seriously corroded bolts and they have never failed.

[InitialDave]

Yep, those Irwin extractor sockets are excellent, I have a set myself.

Though to give yourself a better chance, if there's access to where the thread comes through on the underside, give it a clean up with a small wire brush and a spray with good penetrating oil (PB Blaster or PlusGas are both decent).

[Rich1973]

Maybe not for this particular bolt, but get a set of single hex sockets. Far superior to the usual bi-hex.

[zsdom]

What size is the bolt?
Could you find the bolt size in imperial, usually they’re a little smaller eg 1/2” is 12.5mm, works a charm on a 13mm bolt head & has got me out of many a predicament in the past

[ian332isport]

zsdom said:

1/2” is 12.5mm

12.7mm if you want to be picky

[5s Alive]

Rich1973 said:

Maybe not for this particular bolt, but get a set of single hex sockets. Far superior to the usual bi-hex.

The best ones are designed to grip the middle of the flat and look similar to Torx sockets. They can even grip partly rounded bolt heads. Slightly tightening the bolt first often breaks the thread free.

[thebraketester]

You could try a punch and a hammer to try and spin it loose

[Skyedriver]

guards red said:

These will take anything out...

https://www.irwin.com/tools/screw-bolt-extractors/...

Ignore the bad review, I have used these many times on some seriously corroded bolts and they have never failed.

Would they work on a gearbox filler plug I wonder?

[InitialDave]

Skyedriver said:

Would they work on a gearbox filler plug I wonder?

Ahahaha, did you remove the drain plug before checking the fill plug wasn't seized?

From experience, you only do that once!

[chazwozza]

Thanks for the recommendations guys, will be picking up some new tools this week I reckon...

[guards red]

Skyedriver said:

Would they work on a gearbox filler plug I wonder?

Should do, assuming the bolt head one of the sockets. They prefer a quick thump with a hammer to seat them before using a ratchet/spanner, but should work okay. Also seem happy with an impact gun.

Last time I used one was on an Alfa Romeo strut pinch bolt. This was a cap screw that was internally rounded. The Irwin removed it with no problems. it was so tight that my breaker bar was bending....