It's a locking nut I need for the outermost wishbone suspension joint.

The nut I need is M12, pitch 1.5mm, thickness 16mm, spanner 18mm, quality/grade 10.

I have one ordered but it may take some time to arrive. In the meanwhile I've found a locking nut I can pick up tomorrow. It's M12, pitch 1.75mm, thickness 12mm, spanner 19mm.

So it will fit but it's not custom designed for the joint mentioned, will this see me through for a few days?

  • No – the nut might "bite" but it will wreck the bolt's thread. Commented Dec 22, 2020 at 19:16

2 Answers 2


You will not be able to use that nut. The pitch is wrong. You'd be in essence trying to force a coarse threaded nut (1.75mm pitch) onto a fine threaded bolt (1.5mm pitch). You will destroy both in the process. Either wait until you get the one you ordered or find one with the correct pitch.


You may be able to force the nut on the threads, but you can be assured of damaging and or destroying something. If the metals are particularly strong, you could destroy the spanner. That's the least likely circumstance.

More likely, you'll cut new threads into the nut or cross-thread the bolt by attempting to secure with the wrong size nut.

If the form of locking nut is the type that distorts the threads as it is secured, you'll ensure even more damage as a result.

The damage created by this action may weaken the assembly as well, increasing the danger of operating the motor vehicle.

It's wise to wait or to locate the correct fastener.

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