mysterious markings on an old nut (BSW? BSF?)

[foxy99]

I bought an old trailer the other week and during the handover noticed one of the axle nuts was missing. The seller seemed genuinely surprised it wasn't there - especially since he'd been using the trailer regularly.

Anyway, being a cautious type, I decided to just take the wheel away after paying for it and planned to return with a suitable nut.

I couldn't find one and just drilled the axle and put a split-pin in it to get me home (5 miles) but an still hunting for the right nut.

I convinced myself it was 1" BSF (10TPI) but after getting the other nut off tonight to examine it am thinking it's 1" BSW (8TPI)

Anyway the point of this post is...

Do the 6 triangles stamped on the outer face indicate anything? Like BSW for example.

I know that on UNC/UNF fasteners (when they were a new thing) there were rings stamped or cast on them for easy identification (well My Rootes parts list says that's the case) so was thinking this may also be an ID thing.

NB if I  could find my screw-pitch gauge I wouldn't need to be guessing and measuring with rulers/verniers but that's all I had tonight








trailer axle has a very coarse 1" thread on it








initial check of pitch looked like 0.1" so 10TPI








AF size corresponds with 1" BSF nuts for sale online








1 1/2" AF spanner is a loose fit








nut from other end of axle has weird stamping on it















looks like pitch is about 3mm or 1/8", not 2.5mm or 1/10" as I originally thought

[tonup]

Thats a ‘stiff nut’. Its where they have stamped the nut to push the areas in front of the triangles inwards to make the thread tighter.
Your vernier does show 10 tpi,, not sure about the tape. Best to measure the male part.

[pptom]

Depending on how old the trailer is, or what it's made from, could be Whitworth? 1" is 8tpi.
Get yourself a thread gauge:

www.ebay.co.uk/itm/404099880126?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=MocLI7r-R_e&sssrc=4429486&ssuid=dhQ-VxozTWK&var=&widget_ver=artemis&media=COPY

[pptom]

Sorry, missed that you already had one that's lost!

[foxy99]

It's pretty old (the trailer).

Full story of my 4! old trailers is on a different thread

It's getting out of hand....


Whitworth-era trailer?

[slater]

Could be UNC.. (60degree angle instead of 55degree for BSW..) in reality doesn't make a huge difference.

[foxy99]

slater said:Could be UNC.. (60degree angle instead of 55degree for BSW..) in reality doesn't make a huge difference. 

You got here before me

I was looking at my Presto Counsellor booklet (the Bible?) and noticed the 1" UNC is effectively the same.

Was .'. straight onto Ebay to see if this would throw any suitable items up and it does widen the net but now worried about the actual width (AF) of the nut as I saw one (BSW) which was too wide to fit in the recess on my wheel.

Having said that just found a listing for 1" UNC and it gives AF that matches mine but you need to buy 10. I'll never use the other 9 lol.

NB I measured the threads on the shaft last night and it's defo 8TPI