Bolt/Screw removal tips and pointers.

[Preen59]

Time for me to be the top guy that I am and contribute positively again..



I've been asked on a number of occasions how to remove a bolt, particularly an Allen/inhex/socket (Whatever name you choose to use..) bolt/screw, so i figured i'd give some good tips and suggestions to help out. Most of these tips will also work for double hex/multi point socket head screws..

Allen keys aren't as good as you think...

Allen head screws are a very, very good screw, but, unfortunately, traditional allen keys don't do them a lot of good.

In most cases, allen keys are fine. However, if you get a screw that is rather tight, you can strip the head of it easily swinging off an allen key. This is because the bend radius on the key makes the pivot point of the allen key lower than the centreline of the screw. Because you are putting the force in one direction, it tends to "push the allen key over" as you are trying to twist the screw. What this does is splay the top of the head of the screw as it pushes it out.

When this starts to happen.. STOP! Don't try and keep going. It's not going to give and you're going to bugger the head of the screw.



Ok, so what can i do now??

I'm glad you asked!

I'd try these generally in this order...

Method 1.
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).

Method 2.

Get a hex socket and a ratchet. This moves the pivot point directly over inline with the centreline of the screw (fixes the problem you have with an allen key). This means you don't put axial load on the tool and all the force twists the bolt.. To a large extent.

You can use a 'T' bar allen key (if you have the room). This fixes that issue aswell and also means you're putting force on it in both directions, which evens it out and stops you pushing it over in the head.

You can also use a cut off piece of allen key and a spanner or ratchet spanner. Great tip for if you're restricted for room and once again, eliminates the issues stated above..

Method 3.
If you can, try some heat. Heat the head up with an oxy. Don't get it glowing hot (you'll soften the head) and i wouldn't suggest this method without some physical guidance if you're not very confident with one. You also have to be careful where and what you're doing this on..



Ok, so i was silly, didn't read this first. The head is stripped. I've made a mess of it..

Is there still some kind of hex left in the head?

Yes!
Ok, you're in luck! Get a hammer and a pin punch, or just a hammer (easier with a pin punch though). Beat the snot out of the top of the head and peen it over a bit. Grab either a T bar allen key, a hex socket or a piece of cut off allen key (last choice, they're hard to pull back out sometimes) and hammer it back into the hex. Give that a go at undoing it. You should be able to get it undone.

No! (Or you did have but the above didn't work)
Gees, nice work!

Here's a few things you can try..

1. Vice grips (preferably with radiused jaws). Put them around the head and do them up to the point that you can only just close them. Try and undo the bolt with them.

2. Get an imperial allen key or allen socket slightly bigger than the metric one (or vise versa) and beat the thing into the head of the screw. Give that a go. (I haven't had great success this way)

3. Drill the head off. I don't like having to do this but sometimes it comes to it. If it's a high tensile bolt, try not to spin the drill too fast and use a lubricant. Considering you're probably doing this in your shed or such, any oil will do really.. Motor oil isn't half bad.

4. Cut the head off with an angle grinder (It's getting worse isn't it?). Only do this as an absolute last resort. I wouldn't advise it, but sometimes you have to. Be very careful doing this that you don't damage the face of the part the screw is attaching.

5. Blow the head off with the Oxy. Using a cutting tip, blow the head off. You can usually do this without doing much damage to the surrounding parts, but it takes skill and not something to attempt first time without some assistance.


I hope this helps some of you first timers out. Remember, if it starts to go.. STOP! And try one of these suggestions.

[Mischa]

good info preeny man can someone add this to a faq diy help thread somewhere

[h100vw]

I find if you strip a 6mm allen bolt, hammering an M8 spline in gets them out easy.

Gavin

[Preen59]

good info preeny man can someone add this to a faq diy help thread somewhere

No wuckers man.

I find if you strip a 6mm allen bolt, hammering an M8 spline in gets them out easy.

Gavin

Yep. That's another good tip. If people have more useful tips, please post them.

No arguing or bitching though, please..

[Peter Jones]

How about some handy hints on which direction to rotate the fastener

Seriously, I had to instruct a guy on how to use a screwdriver once, the whole concept of rotational fastening was completly new to him!

A few of my more inventive metods of removing the offending item.

• Weld / braze the tool to the fastener
• Drill the bolt out from the other side so that when the bit snatches it shocks the bolt into spinning out.
• Sell the car
• Cold chisel
• Dremel or file a slot in the head for a big screwdriver.
• Brute force and ignorance.

But your ideas are good too

Thanks for sharing.

Pete

[h100vw]

How about some handy hints on which direction to rotate the fastener

Righty tighty, lefty loosey

Gavin

[Preen59]

How about some handy hints on which direction to rotate the fastener

Seriously, I had to instruct a guy on how to use a screwdriver once, the whole concept of rotational fastening was completly new to him!

A few of my more inventive metods of removing the offending item.

• Sell the car
• Brute force and ignorance.

But your ideas are good too
Pete

Hahahaha nice one Pete!


Good tips there. I've used all those before aswell. I was keeping it as simple as i could for some starting points for people. I'm hoping to see a lot of small odd tips to help people out. Sharing's caring.

[Mischa]

• Weld / braze the tool to the fastener

never though of that but i like the idea. i guess you could weld a bolt with a regular hex head on there too.

[The_Hawk]

[*]Dremel or file a slot in the head for a big screwdriver.

I was going to say that... I love my Dremel (or should I say rotary tool since mine is a cheap knock off).

[gregozedobe]

Some more :

1 Stay calm, don't lose your temper, think logically. It is often better to walk away and tackle the job the next day rather than keep on going when you are tired, annoyed and not thinking clearly or creatively.

2 If you think you have removed all the fasteners but it still won't come off, double check, triple check, add better lighting, then get someone else to have a look BEFORE you resort to the "knockonometer" (hammer). Yes, I have been guilty of failing to notice one small screw in an obscure place when trying to split the two halves of a motorbike engine/gearbox. I felt a real goose when my mate saw it in less than 2 minutes (see my first point above).

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

4 If it appears rusty/corroded soak it in WD40 or similar for a couple of days (but clean it off throughly before you try to loosen it, as you don't want ANY lubricant on the surfaces that re transmitting your force.

5 Make absolutely certain you use the correct type and size of bit (ie don't use a posi-drive with the extra slotty things on a phillips screw). If there is any slop between the bit and the screw then your bit is wrong (maybe a fraction too small). Too big a bit won't fit in the hole properly either, preventing proper engagement of the working surfaces (double entendre intended). A tight fit can be good with a stubborn screw.

6 Sometimes the head of the screw can get filled up with crap, dirt, paint etc, which stops the bit going all the way in the hole. Clean it out thoroughly, it is always better when the tool goes all the way in the hole (again, double entendre intended)

7 There is a liquid product you can buy that increases the friction between the bit and the screw head. It comes in a very small plastic bottle and it looks (and feels) like iron filings suspended in water.

8 Use leverage if you aren't strong enough.

9 Use good quality tools if you are really going to lean on something, especially if you have added a piece of pipe to the handle to give you extra leverage. When you are really leaning, make sure you aren't pulling the bit off a straight engagement on the screw.

10 Think about what is going to happen to your hand or arm if anything does suddenly let go (either comes loose or breaks). Put some padding if there is anything in the firing line that could cause you injury.

11 If you do break off a bolt or stud I have heard of a device called a "disintegrator" which is a bit like an electric welder, but it can break down the remains of a bolt without damaging the parent metal (no idea how it works, but apparently it requires real skill to operate properly).

I think this thread warrants being a sticky already ?