AF to metric

[malcolm]

I see that a 7/16 AF nut is about the same size as an 11mm nut, but are the threads the same? Will an 11mm nut fit on a7/16ths AF thread?
Help much appreciated!

[rfs1957]

No way. Both pitch and diameter different.

The 7/16 is the Across-The-Flats size of a 1/4 UNF (or 1/4 UNC) nut, nominal diameter is 6.35mm, 28 Threads Per Inch for the UNF and 20 for the UNC.

The 11mm nut in Metric usage is usually a (very rarely used) 7mm diameter thread with 1mm pitch (equals 25.4 TPI) so there is nothing remotely in common - unfortunately

True however that often an 11mm spanner is a better fit than a 7/16 one on our cars ........... since 7/16 actually equates to 11.11mm, and so an 11mm spanner is a tighter fit.

[malcolm]

Thanks Rory, looks like I'll have to find an AF nut! Anyone know where we can get them nowadays?

[mgcjag]

Malcom...just google search..ebay etc..readily available almost everywhere your local car shop will have plenty

[Heuer]

Namrick: https://www.namrick.co.uk/acatalog/Home ... s__15.html

[Series1 Stu]

Hi Malcolm

Some of the specialists do a Jag Box, which contains a selection of nuts, washers, bleed nipples, brass nuts, etc. One of these might be a good way of getting the odds and ends you sometimes find yourself needing.

I think I got mine from John Gordon, but not entirely sure.

It's likely that the nut you need is a 1/4" UNF as they were used more commonly than UNC.

Regards
Stuart

[malcolm]

Thanks all! I'm off to a classic car engine workshop this morning, I'll ask them if they have a couple.

[zigzagsky]

Hi Malcolm,

If you don't get any joy then drop by my house any time. I think I probably have a suitable AF nut left over from my rebuild.

Brian

[malcolm]

Thanks Brian.
I might be getting the bonnet off in the next week or two - are you around?

[zigzagsky]

Hi Malcolm,

I'm at the Classic Restoration Show this weekend but around most of next week but away for much of the first week in April on business (so missing the club meet yet again unfortunately).

Having put my bonnet back on - ideally you need at least 3 and preferably 4 people (two to support while you get the tophat bushes out).

Might be a good idea to soak the tophat bushes in penetrating oil regularly for a week beforehand if the bonnet has not been removed in recent years.

To get mine out required heat, penetrating oil, big mole grips, a drift, lump hammer, large amount of coffee and a good grasp of the Anglo Saxon language dictionary!

New ones went in sweet as a nut!

I'll PM you my number in case you don't have it

[malcolm]

Thanks Brian, I'll ring you shortly!