What bolt size has a 14mm nut?

[rfisher]

Need to lock two 14mm ring spanners together using a bolt, washer, 2x 14mm nuts, washer and nut to get my alternator belt off the tensioner.

What bolt size do I need to get 14mm diameter nuts?

[cnprior]

I think its M12 thread on the bolt.

[SystemOfAFrown]

cnprior said:

I think its M12 thread on the bolt.

Bear in mind that the standard hex size for an M8 is 13mm, so 14mm would be ridiculously small for an M12. That would leave 1mm difference between the flats and the thread OD!

A 14mm hex is usually used on M10 fasteners that have low torque requirements, and will often have a flange head.

[InitialDave]

14mm is on certain M10 nuts, yes, though 17mm is more common.

Not quite following what it is you're trying to do, though?

[4Q]

We use M8 bolts regularly which have a 14mm head

[rfisher]

4Q said:

We use M8 bolts regularly which have a 14mm head

Thanks - I've bought a pack of 5x M8 bolts with washers and nuts.

Hopefully they will have 14mm nuts.

Anyone want 10x 21mm nuts with 14mm internal diameter.

Fit an M14 bolt!

@InitialDave - close your eyes and imagine a nice aviation spanner with 15mm and 14mm ring ends.

The 15mm end is on the belt tensioner, the 14mm end has an M8 (hopefully) bolt through it with a washer on the head and a 14mm diameter nut all the way down the bolt.

Another 14mm ring aviation spanner then sits at 180 next to the first one around a 14mm nut tightened onto the first nut.

Then there's another washer.

Then a final bolt to keep the 2 spanners in place.

I now have a 70cm long spanner with enough reach to get to the tensioner sitting at the bottom of the engine, and plenty of leverage to move it off the belt.

If that doesnt work then I'm getting the welder out!

[InitialDave]

I'm afraid generic M8 bolts/nuts are likely a 13mm hex.

If you just want a longer spanner, and there isn't enough room to use a breaker bar and crow's foot instead, you can buy or make a dedicated extension handle.

https://www.ebay.co.uk/itm/265687172685?

[E-bmw]

Just get a 14/15mm open ended spanner & a.n other combination spanner to lock ring end onto the unused open end, job jobbed.

https://thefarmingforum.co.uk/index.php?threads/sp...

[GreenV8S]

If all you want is a longer handle there have got to be better and easier solution. The ring spanner used to extend a combination spanner that E-bmw suggested works remarkably well, and if that isn't long enough it should only take a few minutes to attach the spanner to a piece of wood. Looking for awkward sized nuts and bolts that you don't already have to hand seems like massive overkill.

[smokey mow]

Look for fasteners used on any Japanese cars, they’re a superstitious nation and don’t use 13mm nuts.

[ARHarh]

E-bmw said:

Just get a 14/15mm open ended spanner & a.n other combination spanner to lock ring end onto the unused open end, job jobbed.

https://thefarmingforum.co.uk/index.php?threads/sp...

This all day every day, why over think it. or just a bit of pipe which every keen mechanic will have stashed in his garage. You can often use a large long reach socket over the end of a spanner and a breaker bar as well.

[Fore Left]

How long do you need?

https://www.amazon.co.uk/dp/B004VRNITS

ETA;

Or an even longer one https://www.ebay.co.uk/itm/322542614373

And if you want a rachet; https://www.primetools.co.uk/product/expert-by-fac...

Edited by Fore Left on Thursday 15th September 08:24

[Captain Answer]

Aviation spanner or similar would be best (handy to have in the box for sure), if its stubborn give it a love tap with a hammer headed pry bar like this if you cant get in a full hammer... https://www.amazon.com/ucostore-Shop-TEK-MOLDING-B...

When that failed before I removed the engine mount and dropped the engine down a bit on a jack to get an impact gun in, then put it back on its mounts when done