L19MUD Posted October 20, 2014 Share Posted October 20, 2014 What is the closest size imperial bolt to a metric M10? It looks like a fine thread to me The thread is in the crank gear on my Bedford TK engine (1973) so I can't just take it to my nearest nuts and bolts shop without pulling it off the crank - which is why I need a bolt of that thread in the first place! I know it is not Land Rover related by lots of people have a lot more knowledge than me of this sort of thing on here. Quote Link to comment Share on other sites More sharing options...
miketomcat Posted October 20, 2014 Share Posted October 20, 2014 Slightly smaller would be 3/8 unf around 9.5mm and 7/16 unf Is a shade over 11mm. Unf is a common fine thread on early British vehicles. Mike Quote Link to comment Share on other sites More sharing options...
secondjeremy Posted October 20, 2014 Share Posted October 20, 2014 Bedford - being owned by American would have been pioneers of the SAE thread system in the 1930's - and probbaly kept using it. By and large manufacturers only changed their threds when they fundamentally re-designed components or made new designs - so by the early 70's its probably still SAE. SAE threds were adopted in UK in the late 40's as the Unified system - naturally known by a different name - UNF (Unified Fine) The nearest to M10 would probably be 3/8 UNF - which has a pitch of 24 TPI (Threads per Inch) Quote Link to comment Share on other sites More sharing options...
ejparrott Posted October 20, 2014 Share Posted October 20, 2014 You've got 7/16" at 11.11mm or 3/8" at 9.525mm....its all very well saying 'closest size' but are you looking for something slightly smaller or slightly larger?! An thread slightly smaller than M10 but with roughly the same pitch could be 3/8" x 20TPI, which gives potential for 3/8"BSF, that crops up a fair bit on the older Land Rovers Quote Link to comment Share on other sites More sharing options...
miketomcat Posted October 21, 2014 Share Posted October 21, 2014 Or you could download a Zeus book and measure it up properly. Sorry can't find the link right now. Mike Quote Link to comment Share on other sites More sharing options...
L19MUD Posted October 21, 2014 Author Share Posted October 21, 2014 Thanks for the help all it is slightly smaller so looking like it is most likely 3/8 UNF I have a proint out of the Zeus book somewhere - I will find it and measure properly Quote Link to comment Share on other sites More sharing options...
ejparrott Posted October 21, 2014 Share Posted October 21, 2014 Just need to check the pitch then. for 3/8", BSF is 20TPI, with UN each side of it at 24 for fine and 16 for coarse....16 TPI compares pretty well with 1.5 so an M10 bolt would help identify that pitch if its a very very close pitch match, for 20TPI then an M8 at 1.25 is also very very close, and for 16 then an M6 at 1.00 isn't far off. Quote Link to comment Share on other sites More sharing options...
L19MUD Posted October 27, 2014 Author Share Posted October 27, 2014 Just in case anyone needs to remove the crank gear from a Beford TK it was 3/8 UNF Thank you for the help! Quote Link to comment Share on other sites More sharing options...
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