Bolt/Screw removal tips and pointers.

[Mrk_Mickey]

Very good info Could have used this 6 months ago but I'll know for next time!!

[Preen59]

Use an impact driver - this gives a straight on go at the screw and adds in a jerking force too (both good).

Not such a good idea on smaller screws. I avoid using an impact driver on anything less than about 16mm bolts if they're pretty tight.

The problem is that the impact can damage the head. I've done it before in a vac form tool, and buggered it. I had to peen the top over, bash a T bar into it and get it out that way..

If they're too tight you're better off using a method that you have feel with.

[rayray086]

Great info!

I haven't tried this personally, but for some of the bigger bolts that are rounded, I've heard these products are great:


http://www.sjdiscounttools.com/lis19250.html

[gregozedobe]

3 Use an impact driver - this gives a straight on go at the screw and adds in a jerking force too (both good).

Not such a good idea on smaller screws. I avoid using an impact driver on anything less than about 16mm bolts if they're pretty tight.

The problem is that the impact can damage the head. I've done it before in a vac form tool, and buggered it. I had to peen the top over, bash a T bar into it and get it out that way..

If they're too tight you're better off using a method that you have feel with.

How did using an impact driver cause damage to the head ?

If the bit fits properly it can only slip if the metal of the screw or bolt head is inadequate to transmit the torque required to undo the bolt, and that is not due to the use of an impact driver.

We might have to agree to disagree

I have had lots of success with an impact driver on stubborn screws down to 5mm stem diameter, and particularly when the screws are made of crap metal. The jerking rotation of the impact driver seems to break the "freezing" of the thread (common on steel screws into aluminium thread), whereas if I simply gradually increased the torque I just twisted the heads off (did I mention crappy 1970's spanish "steel" screws on Montesa trials bikes ?).

Once I got them undone I replaced them all with better quality high tensile allen head screws, no further problems (with getting screws undone, anyway).

[Mischa]

How did using an impact driver cause damage to the head ?

If the bit fits properly it can only slip if the metal of the screw or bolt head is inadequate to transmit the torque required to undo the bolt, and that is not due to the use of an impact driver.

We might have to agree to disagree

I have had lots of success with an impact driver on stubborn screws down to 5mm stem diameter, and particularly when the screws are made of crap metal. The jerking rotation of the impact driver seems to break the "freezing" of the thread (common on steel screws into aluminium thread), whereas if I simply gradually increased the torque I just twisted the heads off (did I mention crappy 1970's spanish "steel" screws on Montesa trials bikes ?).

Once I got them undone I replaced them all with better quality high tensile allen head screws, no further problems (with getting screws undone, anyway).

Get a hammer and preferably a pin punch (about the same diameter as the head of the screw) aswell (you can do it with just a hammer, but you have to be more careful). Give the top of the screw a couple of good hard hits on the top of the head. This will 'jarr' the screw and can break the lock on the thread, which (It might surprise you..) makes a crazy amount of difference. After you've done that, give it another go.

This works especially good on countersunk head screws as the angle on the head of the screw can lock on the countersink (this can happen especially in things that fluctuate a great deal in temperature).

you two are talking about the same concept

[Transporter]

I made this little helper for bolts on water pump on Daewoo Nubira, when everything I new failed. It worked well. Also WURTH ROST OF is much better that WD40 on corroded bolts and nuts.
BoltRemovingTool.09.1.JPG

It could be made from hex nut drilled to diameter of the bolt head needed and the grab screw holes drilled and tapped to the sides of the hex.
I use dremel tool to grind the flat side or sides (for the grab screw to sit on) it would depend from how good is the access to the offending bolt.

[The_Hawk]

ahhhh necesity, the mother of all invention

Nice work there!