Don't lose your Nuts

[Paul H (admin)]

I checked the nut and drive pin on my new Minn Kota electric outboard, preparing for the mighty Thames Raid 2017.

To my surprise it is not metric. But then I realised it was made in Mexico with information in English and French, clearly for America and Canada markets.

It's definitely 5/16" and the hex nut diameter is 1/2". This is the "US Nut Size", but I don't know what the thread pitch is or if its Whitworth, UNC, or whatever. I want to buy some spare nuts, but need the thread type.

So, for all you Imperial chaps with less than perfect eyesight I have taken some close ups. The calipers were set to 0.400" for reference:



 and



I count 22 tpi, but 24tpi is the UNF size. It's easy to count +/-1 in the pics though. (18tpi is UNC)

Can anybody work out the nut type I need?   Also the drive pin is 1/8in or 3mm - what is best material?

thanks in advance
Paul

[Paul H (admin)]

On eBay stainless nyloc nuts 5/16th were good prices. I bought UNF and UNC, so one will fit.

My leisure batteries seem to have 5/16 studs, M8 nuts jam. Hopefully I'll have spare nuts for battery connections.

[Jeremy]

It's 5/16" UNF (5/16" x 24) according to the data for the motors with the 3/8" shaft.  

[Paul H (admin)]

Jeremy wrote

It's 5/16" UNF (5/16" x 24) according to the data for the motors with the 3/8" shaft.

Thanks Jeremy. Good old Royal Mail first class post delivered the UNF nuts I ordered yesterday....and they fit perfectly. I have 20 spares, but I'm not paranoid!

Cheers
Paul

PS How is your house project doing?