Exhaust flange bolts Lister D

I bought a new exhaust and flange for my Lister D. New flange has painted up nicely and I've sprayed the exhaust with black heat resistant paint having been pointed in the direction of Screwfix by another forum member - thank you.

The flange is slightly deeper than the original so I need slightly longer bolts. Does anyone know what the thread is please?

Many thanks.

the thread is whitworth, I'm guessing 5/16 or 1/4, measure the od of the thread.

Maryalice

maryalice wrote:the thread is whitworth, I'm guessing 5/16 or 1/4, measure the od of the thread.

Maryalice

THanks for the help but, forgive my novice status....what is 'the od of the thread'?

5/16 0r 1/4

maryalice wrote:5/16 0r 1/4

...and how would I measure that please?

Micrometer, vernier or a six inch/twelve inch rule.

Suggest you invest in cheap digital caliper and Zeus workshop booklet

I have a set of digital calipers....and I used to teach maths! It's just that I don't understand what od is or the 6/12 inch rule and I am asking for a little clarification from those more experienced in this area. So far I just feel more ignorant.

Here you go, link to new bolts. Mary is being a woop so I've shared a link. For future reference od is outside diameter.....

https://www.stationaryengineparts.com/Whitworth-Bolt-5-16-x-1-1-4-Lister-D-Exhaust-Flange.html

[quote="Appletop"]Here you go, link to new bolts. Mary is being a woop so I've shared a link. For future reference od is outside diameter.....

https://www.stationaryengineparts.com/Whitworth-Bolt-5-16-x-1-1-4-Lister-D-Exhaust-Flange.html

Thank you Appletop....once you share something somebody learns something new. We all have things to learn and I have ordered a Zeus and I will be most interested to read it. Thanks again.

I tried to send the "OD =  Outside Diameter" comment yesterday evening but I had G&T in one hand and crossword in the other and, evidently, failed.

Generally speaking British and US engines will use imperial threads

British Standard Whitworth (BSW) and  British Standard Fine (BSF) Same OD but different number of threads per inch (TPI).

US examples are Unified Thread Standard, UNC =  Coarse, UNF = Fine.

UNC is very similar to BSW in OD and TPI but the thread form in different - 60 degree angle as opposed to 55 degree.  So, at a pinch, you could substitute, the exception being  ½” BSW and ½” UNC which have different TPI
You may also come across British Standard Cycle thread BCS and British Association BA.  Endless possibilities to get it wrong

I, like most others I guess, have accumulated a bunch of thread tables - you are most welcome to a copy.
PM me if you wish.

The bolts are 5/6th Whitworth.

Pete.

Might be of use.

Couple more useful ones.

Thank you so much everybody, especially to StuartTurnerSteve for taking the time and trouble to reproduce those charts for me.

Thank you again.

ajcooper4 wrote:Thank you so much everybody, especially to StuartTurnerSteve for taking the time and trouble to reproduce those charts for me.

Thank you again.

Seconded!

Google is your friend

If you want a job lot PM me.