Thread sizes

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philthehill
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Re: Thread sizes

Postby philthehill » Wed Sep 04, 2013 7:40 pm

Richard
Never thought to check the oil pressure relief valve cover with the digital calliper gauge just measured with the imperial vernier gauge and it came out as 13/16" and still does. Measured again with the digital gauge 0.824" and yes you are right it is 1/2" x 14 TPI BSP.
Phil


philthehill
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Re: Thread sizes

Postby philthehill » Thu Sep 05, 2013 7:31 am

Richard
Two more for your thread list.

1. Steering arm to swivel - 1/2" x 20 TPI UNF.
2. Steering arm to swivel (8cwt van) - 5/8" x 18 TPI UNF.

Note: In posts where I have given a confirmed size that size has been checked against a die nut of the specified thread/size.

Richard
Whilst the threads/size in your list are factory original there is a trend today to use UNF threads on Minor suspension components.
Is it worth providing an alternative list?


IslipMinor
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Re: Thread sizes

Postby IslipMinor » Thu Sep 05, 2013 8:30 am

Phil,

Thanks for the additions - list has been updated. Keep them coming!

Yes, for suspension part replacements, UNF can be seen instead of BSF, so I have added a note to that effect.
Richard



philthehill
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Re: Thread sizes

Postby philthehill » Thu Sep 05, 2013 12:56 pm

Richard
A couple more for the list:

1. Oil pressure switch - 1/8" NPT27.

2. Brake light switch - 1/8" NPT27. Both screw and spade terminal type switches.

Both of the above switches have a taper thread but the thread in the engine block and brake pipe junction block are parallel threads.

Phil


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Re: Thread sizes

Postby IslipMinor » Fri Sep 06, 2013 11:02 am

Phil,

Interesting one. I had thought that they were 1/8" BSP (28TPI), as after all it is a 'British' engine, but after checking the tapping in the spare block for the oil pressure take-off, I also think it is 1/8" NPT (27TPI). I don't have a spare brake light switch, but it would make sense that it is the same thread.

Table updated to include both of these. Would like 'absolute' confirmation though!!

On the pressure relief valve cap, I wonder if the thread is actually 1/2" NPT? It has the same TPI as BSP (14). Have just checked the spare cap against a 1/2" BSP split ring die, and it screws in, but I have nothing to set the die to, so not a proper test, and don't have a 1/2" BSP tap.
Richard



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Re: Thread sizes

Postby macktel01 » Tue Sep 10, 2013 2:50 pm

Hi
Can any body tell me the thread size of the 2 spare holes next to o/s/f damper as i would like to mount a bracket there
I have tried a 5/16 bsf as stated for dampers to x member but no go!
Thanks in advance Dave

philthehill
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Re: Thread sizes

Postby philthehill » Tue Sep 10, 2013 7:00 pm

Richard
I can confirm the threads of the oil pressure switch and brake light switch are as stated as I have checked both housing threads and switch threads with both a tap and a die nut.


philthehill
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Re: Thread sizes

Postby philthehill » Tue Sep 10, 2013 7:07 pm

Dave
The spare holes adjacent to the dampers are 5/16" BSF. I have just tried a 5/16" BSF tap and a 5/16" BSF damper bolt in the holes to confirm and all OK. You must have paint/crap in the holes so need to clean out the threads. Put a flat on a spare damper bolt, screw it into the hole and that should clear it if you do not have a 5/16" BSF tap.
I use the spare holes on my minor to locate one end of a brace between the bulkhead and front cross-member because under heavy braking with a fibre glass front fitted the front chassis legs tend to bend.


bagpuss1947
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Re: Thread sizes

Postby bagpuss1947 » Sat Sep 14, 2013 4:11 pm

Hi
As a little addition to thread sizes , the track rod ends can be 5/8 BSF or 5/8 UNF .
The way to tell is use a front hub nut on the male thread coming out of the rack or the oilpipe banjo bolt on the ball joint.
The ones supplied to me by the people who rebuilt my rack were BSF but I managed to obtain the correct UNF ones from www.ukmgparts.com under the part no. GUJ169 { UNF] or GUJ 158 for the BSF ends
If you obtain the wrong threaded ball joints ,they will on screw on a little way before locking up.
Hope this helps

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Re: Thread sizes

Postby Gubben » Mon Nov 11, 2013 11:43 am

mike.perry wrote:It is no good relying on a list for thread sizes, during production nut and bolt sizes were changed and during a 40 to 60 year life span previous owners will have fitted whatever was available. There are also special sizes where the thread size does not match the spanner size, for instance Series MM engines had metric threads and Whitworth spanner size bolt heads. Thread pitches can be useful but most people would probably not know the relationship between a 20 tpi and a 24 tpi thread.
The best solution is to buy a good set of spanners and sockets. A full set of open enders and some ring or combination spanners as required. A set of combination spanners on its own is no good as a nut and bolt has two ends and a combination spanner has the same size on both ends. A set of A/F spanners from 3/8 to 1 in and 1/4 to 7/16 Whitworth should cover most of your needs. If you have not got a tool don't borrow it, buy it, then you build up your collection and you have the tool for next time.
Now to study Richard's comprehensive list
Are you sure about metric threads on MM? I notised that the thread for the bolts connecting gearbox to engine are not metric (UNF-probably). If there are more not metric threads I don´t know yet - just about to start working with my MM side valve engine.
Thomas

Gubben
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Re: Thread sizes

Postby Gubben » Mon Nov 18, 2013 8:16 am

At a second thought! Could metric fine thread be almost the same as UNF?

hdavy
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Re: Thread sizes

Postby hdavy » Tue Dec 17, 2013 5:34 pm

Mike -even with bags of spanners it's still really useful to have Richard's list because if you lose a bolt you need to know which one will fit that blank hole. And I don't have to tell you about metric fine.......... Happy Christmas

hdavy
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Re: Thread sizes

Postby hdavy » Tue Dec 17, 2013 5:42 pm

Oh and what please is NPT?

katy
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Re: Thread sizes

Postby katy » Wed Dec 18, 2013 4:17 pm

N = National
P = pipe thread
T = tapered
Talk slow, think fast!

symington1947
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Re: Thread sizes

Postby symington1947 » Wed Dec 25, 2013 6:44 pm

The most concise thread chart is called ZEUS (drilling and tapping sizes),you will find it on the net.
regards
colin.

symington1947
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Re: Thread sizes

Postby symington1947 » Thu Dec 26, 2013 8:34 pm

in response to TUDGES QUOTE By The time you have brought all the correct nuts and bolts and added the cost up ,they will be worth more than the moggie!!!!!!!!!

philthehill
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Re: Thread sizes

Postby philthehill » Fri Dec 27, 2013 10:53 am

No matter how many different nuts and bolts you have there will come the time that the nut or bolt you want is the one you do not have so keep a gash box and a good set of taps and dies and then you can make your own. Yes the price of new good quality nuts and bolts is unbelievable so if I have a nut or bolt and it is serviceable it goes in the gash box.
As regards the Zeus data charts and reference tables I am always referring to it and it is a most useful addition to my tool box. Anyone who drills holes and uses taps and dies should have a copy. I have not used the Log and Anti-log tables for some considerable time though.[frame]Image[/frame]


Trickydicky
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Re: Thread sizes

Postby Trickydicky » Fri Dec 27, 2013 1:34 pm

Over the years I have had many different copies of eng data tables, usually got them given by the tooling reps when they came into the factory or you collared them on the way out :D
Got my first zeus tables as an apprentice in 79,on my third copy now as my old ones got dropped in the suds so many times. For anything thread related this is the one book that has it all.
Richard

Opinions are like people,everyone can be different.

smithskids
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Re: Thread sizes

Postby smithskids » Sat Feb 08, 2014 11:57 am

Zeus is excellent but if you need other odd threads this is good, albeit this is the 1919 edition :D[frame]Image[/frame]

alainmoran
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Re: Thread sizes

Postby alainmoran » Thu Aug 21, 2014 9:21 pm

Tudge wrote:Our prayers have been answered! Better get on fleabay to find a load of whitworth & AF spanners!
Better than that ... next time you are at the car-boot and someone is selling sockets ... have a fish through and as soon as you find a whitworth, ask them "how much for the box" ... often you'll get the answer of a fiver or so ... snatch their hand of and run away before they change their minds ;)


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