UNF/UNC? What's right for XJS nuts/bolts?

[XJR-S]

So, I'm after a few nice stainless nuts and bolts to tidy up my engine bay. What should I be buying? Found out the hardway all of my stainless metric nuts are useless

[davidr]

The basic issue is that the car was in continuous production for 21 years so there's all sorts on it! don't give up on your metric set - there will be some of the newer components that will be metric.
Most are a mixture of UNF and UNC.
Sorry - there's not a clear answer to this one!

[ptjs1]

XJR-S,

As David has said, your car is a mixture of standards. So, you'll definitely need some metric for some of the under-bonnet replacements.

Every time I take off a non-load bearing nut, I try and replace it with stainless. I am for ever having to check thread pitch etc to know which standard to use.

Paul

[XJR-S]

Thanks! That's a pig isn't it Hey ho!

Much appreciated.