Prop nut size ?

[oldgit]

Does anybody know the probable shaft nut size and/or the thread likely to have been used on a Mk 1 Flybridge Princess 33 with pair of 165 hp engines and where you could source a replacement nut. ?
Very corroded item.
Has been suggested a 3/4 Whitworth and a quick glance appears to shown 10 threads per inch .

 

[colhel]

No idea what Princess would have used, assuming the OD is 3/4 and it's 10 TPI, English would be as you say 3/4" BSW or if the thread is American 3/4" UNF, which would probably fit the BSW anyway. Another possibility would be if the thread OD is 20mm, it could be M20x2.5.
Let me know if you want me to make you one.

 

[omega2]

Paul Williams, www.clementsmarine.co.uk

 

[oldgit]

No idea what Princess would have used, assuming the OD is 3/4 and it's 10 TPI, English would be as you say 3/4" BSW or if the thread is American 3/4" UNF, which would probably fit the BSW anyway. Another possibility would be if the thread OD is 20mm, it could be M20x2.5.
Let me know if you want me to make you one.

Thanks for all comments.
Pretty sure thread is pre metric.
Will suggest he starts search with Clements and go from there. Fred.

 

[lydiamight]

Have a look at http://www.zincsmart.com/ under the section "prop nuts and anodes" They will cut the appropriate thread for you if it is non standard.
Also fairly close to you---Canterbury. No connection other than a very satisfied customer, they are very helpful indeed

 

[Spi D]

Think you need a thread pitch gauge to find out

 

[oldgit]

Will update on final outcome.