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Thread Pitch for M20

Does anyone know what the thread pitch is on a 1939 M20? I am trying to buy a Tap and Dye set. Thank you!

email (option): rwmotorsports@sbcglobal.net

Re: Thread Pitch for M20

hi roy,there are numerous threads used on the m20,british std whitworth,BSW,british std fine BSF,british ascociation,BA,
british std pipe taper,BSPT,british std pipe parrallel BSPP,british standard cycle BSC,and at least one ISO metric
(m14 x1.5 spark plug).
it is not really practicle to have taps and dies for all,some cycle and engine parts will not be available anyway.if you return to the web page there is a technical section where most commonly used threads are listed /explained,it may be you only require certain taps etc
these can be bought singly at good shows or through various dealers,use the search box to find more relevant info,if you get really stuck just shout.
robb at british tool who posts on this site stocks most of these,im sure others will post their favorites a well
hope this helps cheers rick

email (option): richardholt@rocketmail.com

Re: Thread Pitch for M20

Hi Roy..You will also come across threads of varying diameters that are 20 TPI...these are also cycle threads and though they don't have the usual 26TPI pitch for cycle thread they conform to the Cycle thread pattern in other respects such as thread angle. A micrometer, a set of Imperial thread gauges and thread information for the different thread specifications(all on the internet) are well worth getting if you are unfamiliar with them. Taps and dies are still available for most threads from specialist suppliers but to get them all, including the larger 20 TPI ones would require a subtantial investment running to hundreds of pounds. I have acquired the full set more or less but it has taken a number of years. Rick has given a good piece of advice in that you need to work out which ones you need the most to carry out any work you are planning and start with those..Ian

email (option): ian@wright52.plus.com

Re: Thread Pitch for M20

Hi Roy,

I have a couple of sets in stock at the moment.

I can PM you with the info. On an M20, anything larger than 3/8 inch is 20 TPI. If it is 3/8 inch or less, they are 26 TPI.

There is some BSPP, BA, BSF also.

All thread pitches (BSCY) are 60 degree included angle.

Cheers,

Robb

email (option): britool51@hotmail.com

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