If Not Metric?

[MichaelSB]

I have just got back from spares day and among my many purchases is a bag of assorted stainless nuts and bolts, my question is, what other thread would be on my 1995 XJS where caged nuts have been used?

I have found some that are metric but others are not and look to be a tad finer thread.

For those wondering what I am doing, I am replacing as many non structural nuts / bolts and screws as I can with stainless as I don't like rusty nuts, if you know what I meen

[steveww]

Being a British car my guess would be UNF and UNC threads. Really small one may be BA.

[ptjs1]

Michael,

Clearly the lure of Spares Day forced you to part with some hard-earned cash!

If you haven't already got one, you might want to invest in a pitch gauge to help you check such nuts. A small price and can save you messing up a nut or bolt through forcing the wrong size. Alternatively, I keep a few spare nuts and bolts of common sizes clearly marked with tippex to test any unknown items for metric or imperial threads. As with Steve's view, I suspect that coarse thread captive nuts could be UNC on your car.

Paul

[JED1961]

maybe even BSF !! depending on your cars age

[poprivet]

If you can find a copy of the club magazine for November 2005, there is an excellent 2 page table listing all possible thread combinations. (Named 'Nuts, Bolts, Threads & Spanner sizes'). I have a copy hanging up in the workshop and its helped a lot over the years.

If you combine this with a micrometer and a copy of Zeus data charts there isn't a single bolt anywhere on the car that can't be identified.

Of course as well as size, two other factors come into play, tensile strength and corrosion resistance. Stainless steel comes in many grades and some of them corrode in the presence of salt water and mild steel as much as any other.

[steviepip]

I've recently done a partial refurb on my IRS. Most of the nuts and bolts were UNF.
Oh this is on an 87 plate 5.3