THREADS

[Jpallis001]

Hi - as suggested a Thread on THREADs. I will post what I discover based on my experience with a 1933 SV Minor:

big end nuts = 1/4" BSF (castle head)
little end stud = 1/4" BSF
Head Nut = 5/16" BSF

[Ian Grace]

Thanks, John - very useful.

Most of us know that most threads used on the Minor are BSF, but it will be very useful to record the sizes. It would also be very useful to record various bolt lengths - for such things as the prop shaft bolts, clutch cover plate bolts, etc., so members can order using the list as their reference without further research - particularly useful if the bolt in question is actually missing. (Bolts are defined by the plain shank length - measured from under the head to the start of the thread - measured in tenths of an inch. If there is no plain shank, then it is not a bolt, it is a setscrew.) It will also be very useful to record all the threads that are not BSF or BA - such as the rear hub locknut thread, the steering box locknut thread, etc.

Once we have gathered sufficient information here - I'll put together a reference list and post it on the website for everyone's future benefit.

Thanks again,

Ian

[Ian Grace]

Here's one that isn't BSF - the steel banjo bolt securing the bottom of the oil feed pipe to the head on OHC Minors and M Types is 3/8" BSP.

I suspect that the threads on the SV Minor external oil feed pipe from sump to pump are also BSP - can someone confirm this?

[Jpallis001]

Hi Ian - have just checked that one; SV oil pipe (sump to pump) = 3/8 BSP. Will need to try to make that one this week!

John

[Jpallis001]

Nut for Spring Shackle Pins = 1/2 BSF

[mowersman]

For those of us who have hydraulic brakes, the rear banjo is 1/2 UNF. I don't know about the front, I haven't checked yet!

[ian judd]

I'm sure UNF is a post - war thread. Could Lockheed threads be American since it's an American company? Some of the 'nuts' need American spanners.

Ian

[mowersman]

I think UNF is just the new name for the old NF American thread. They are the same, just under a different name.

[Jpallis001]

And then there in UNC or NC!

Prop shaft bolts = 5/16 BSF - 30mm - with castle nuts

[Jpallis001]

pinch bolt - brake operating lever to brake cam shaft = 1/4 BSF, 30mm