Nut/Bolt/Screw

[Flippy82]

Hi could anyone tell me where I can purchase one of these negative battery cable nut/bolt or screws from. This one is rounding and I’ve tried near every tool to get it off but it’s just not happening looks like I’m going to have to cut the head off of it to replace it. Before i do do that I want to have a replacement ready to go. Much appreciated. 

Edited 11 hours ago by Flippy82
Autocorrect fail

[rd457]

On the other side there's going to be a nut that'll almost certainly be welded onto the frame. If you just cut off the head, how then do you plan to deal with the chunk left stuck in that nut without damaging said nut?

If you manage to preserve the nut intact and fully remove the bolt, to replace the bolt you'd need to know the diameter of the threaded section, the pitch of the threads, the length of the threaded section, and generally to replace a bolt you need to know the strength as stamped onto the head (though in this case strength probably isn't important).

You could in theory destructively get rid of both the existing nut and bolt and replace them with similar/same, but then you face the difficulty (and dangers) of welding the new nut on, unless you're just going to hold it still from the bottom while tightening and hope it never works loose.

I'd suggest that you just try harder.

• Spray some penetrating fluid (like WD40) on there and give it a chance to soak in.
• You could try giving it some love taps with a hammer (percussive shock).
• You could try FIRE 🔥 (heat it up with a blowtorch).
• And you could try sockets designed to be used for rounded bolts.

On that latter note, there are special sockets designed to grip on like this:

However there's alternatively a line of sockets produced by sealey going by the name "lock-on" that are like normal sockets except they have some notches cut into them and can work on bolts that are up to 85% rounded. I saw a video on youtube a while ago of someone reviewing them and I was very impressed. You can find a 3/8" set for £22.45 currently on amazon, search for Sealey AK2741, or AK2742 for a 1/2" set. They also come in impact rated versions.

I don't suggest use of thermite (per that big bang theory episode 😂).

[troy45]

Another option to grip the current bolt would be to use a set of mole grips to clamp onto the head of the bolt and see if it will loosen that way. 
 

Or assuming it was originally a 10mm head you may be able to hammer a 3/8” imperial socket onto it and hopefully grip it better. 
 

Heat would help as well you’d just need to be very careful not to damage the earth cable. For replacing the weld nut underneath it you may find it pretty difficult to access without removing the suspension strut. 
 

Replacement bolt will either be M6 or M8 thread and easy enough to get hold of - if you can find it on a parts site like 7zap that will tell you the thread and length, tried looking myself but couldn’t find which section it was hiding in. 

[Flippy82]

8 minutes ago, troy45 said:

Another option to grip the current bolt would be to use a set of mole grips to clamp onto the head of the bolt and see if it will loosen that way. 
 

Or assuming it was originally a 10mm head you may be able to hammer a 3/8” imperial socket onto it and hopefully grip it better. 
 

Heat would help as well you’d just need to be very careful not to damage the earth cable. For replacing the weld nut underneath it you may find it pretty difficult to access without removing the suspension strut. 
 

Replacement bolt will either be M6 or M8 thread and easy enough to get hold of - if you can find it on a parts site like 7zap that will tell you the thread and length, tried looking myself but couldn’t find which section it was hiding in. 

Thanks for the reply

just ordered a new set of mole grips. I’m hoping that does the trick. I don’t want to go near it with heat because of the cable I’m trying to keep that intact. I never knew they had a weld nut underneath them so that rules out cutting it off. The nut itself if like putty when you go near it with any sort of tool Ford certainly didn’t make it easy for these cars to be repaired that’s for sure. 

[troy45]

Bit of digging on web suggests it’s an M8x20 bolt - assuming it’s the same as that fitted to the Mk2.5 RS, no reason why it’d be different imho

Don’t worry about the tapered end that’s just a dog point to allow the fixing to be gunned up without needing to hand start it first. Maybe also needed if the original bolt cut its own thread into the weld nut but that’s not an issue now 🙂

[Flippy82]

3 hours ago, troy45 said:

Bit of digging on web suggests it’s an M8x20 bolt - assuming it’s the same as that fitted to the Mk2.5 RS, no reason why it’d be different imho

Don’t worry about the tapered end that’s just a dog point to allow the fixing to be gunned up without needing to hand start it first. Maybe also needed if the original bolt cut its own thread into the weld nut but that’s not an issue now 🙂

Thanks again Troy, that information will come in handy. Now I know what to look for and buy it’s just a matter of getting the thing off to get the car started, I hope.