Listeroid Fasteners- Metric, Whitworth or BS?

[Rick Rowlands]

Anyone know what the fasteners on a Listeroid are? Certainly isn't American and another poster thought they might be BS or Whitworth.  I need to buy wrenches and sockets but need to know what to get.

[hotater]

Two six inch Crescents that'll open to at least 7/8" for the fuel tappet and lock nut,  and a ten inch for 90% of the others,  and a 14 inch for the head bolts.  You're set.   

The fasterners are mix and match.  The good old  "Yakamoto Fits'em All" is the best wrench for the money.

[biobill]

 hotater,
   How can a guy who's so respected as a gunsmith be such a hack as a mechanic?   You forgot to mention the claw hammer.

Rick,
  I'm a bit of a hack myself when necessary, but between my english and metric sets, I can move anything on the engine. Head nuts are 28mm if I recall which allows the use of an actual torque wrench('tater)

                                                       Bill
 
                                                   

[Stan]

Hottater yall forgot what we up here call a Saskatchewan socket set (a pipe wrench).
Stan

[listeroil]

I am sure the threads on listeroids are BSW (british standard whitworth) and and BSF (british standard fine).  I have bought a few indian spares for my genuine listers and they are bolt for bolt the same. It seems like the Indian engines pretty much copied the british design. All the threads on british lister cs engines are either BSW or BSF. This is a table BSW and BSF threads per inch and the link below is a good description of the british standard system.


BSW       TPI            BSF     TPI
1/4          20            1/4       26
5/16        18            5/16     22
3/8          16            3/8       20
7/16        14            7/16     18
1/2          12            1/2       16
9/16        12            9/16     16
5/8          11            5/8       14
11/16      11            11/16    14
3/4          10            3/4       12

http://www.timebus.co.uk/rlh/whitworth.htm

 In Britain, road vehicles, aeroplanes and  machinery until the 1970s used British Standard thread forms. The following families of threads existed;
miniature sizes known as British Association (BA). BA size numbers are in reverse. The lower the number, the larger the bolt size, so 0 BA is the largest and 16 BA is the smallest. BA sizes are mainly used in electrical equipment.
 
coarse threads known as British Standard Whitworth (BSW)
 
fine threads known as British Standard Fine (BSF)
 
The U.S. equivalents are the Unified Thread System formed by ANSI/NATO in 1948. These standards were agreed between Britain, Canada and the US and were based on the previous American National standard, except with rounded roots and optionally rounded crests. This composed the following:
miniature sizes below 1/4 inch (UNM), with roots from an old American Society of Mechanical Engineers (ASME) standard
coarse threads (UNC)
fine threads (UNF), with roots from old Society of Automotive Engineers (SAE) and ASME standards

Whitworth threads are used for most mechanical equipment in the RLH.

With the UNF/UNC system the number stamped on the wrench or socket is the dimension of the hexagonal bolt head measured across the flats (AF = Across Flats); so the wrench required for a 1/4 UNC bolt would have be stamped 7/16. Whitworth wrench sizes, however, indicate the size of the bolt, i.e., a wrench required for the equivalent 1/4 BSW bolt will have 1/4W stamped on it.

Whitworth heads are NOT the same size as the equivalent UNC/UNF - they are larger. For this reason, it is imperative that a set of Whitworth wrenches are purchased before working on any antique British machinery. Otherwise, expect rounded-off heads and busted knuckles, trademarks of the careless craftsman.

Whitworth wrenches and sockets are available through clubs that cater to British cars. It's also a good idea to get a set of taps and dies to fix the attempts of those who have gone before you in the vain attempt to convert, intentionally or otherwise, to SAE format.

Another area that causes confusion is the fact that some BSW/BSF nuts can be screwed on UNF/UNC bolts and vice-versa. Under NO circumstances should this be practiced. Most of the coarse threads share the same threads per inch, which means BSW nuts can be screwed onto UNC bolts and vice-versa (the exception to this being ½ inch, of which the BSW size has 12 threads per inch whereas the UNC size has 13). Whitworth and UNC/UNF thread forms differ greatly, the primary difference being the thread angle. Consequently, if these fasteners are interchanged, considerable loss of holding force, fatigue resistance and strength will result.

Some outfits in the US have been known to sell so-called Whitworth hardware, which has SAE sized hex heads mixed with Whitworth thread forms. This really only serves to cause confusion and increase the risk of the wrong equipment being used in future. Fully correct Whitworth fasteners are available in the US.
 
Abbreviation    Name              Introduced       Diameter/ Range      Thread angle, degrees    Notes
   l
   
BSW  British Standard Whitworth       1841              1/16 to 2.5 inches                     55                  Coarse
   
BSF   British Standard Fine                 1908                3/16 to 1 inch                        55                   Fine
     
UNC   Unified National Coarse             1918                0.05 to 1 inch                        60
     
UNF   Unified National Fine                 1918                0.05 to 1 inch                        60


Mick

     

[Rick Rowlands]

Thanks for the info.  I am going to measure up a few of the nuts and order the appropriate sockets.  I'll keep a set of seperate tools just for the Listeroid.

[Stan]

You'll find that 3 possibly 4 withworth wrenches will fit 90% of everything on a Lister.
Stan

[OffGrid]

On my engine all the heads measured BSW but the thread was good old SAE Nation Course. Not the Con rod or the dipper but all the external stuff. Since the Listeroid hardward was not of the highest standard shall we say, everthing has been changed to good old NC, somthing I understand.

[listeroil]

The pitch angle on bsw is 55 deg and the thread on unc is 60 deg they are a close match and fit in most cases. However it is not good engineering to mix them up. Not all the threads are the same tpi 1/2"bsw is 12 tpi and 1/2"unf is 13 tpi.As far as  sockets and spanners are concerned there are af or metric equivalent sizes that fit. the only one thatyou need in whitworth is 1/4 whitworth (5/16" BSF) for the crankcase door and water jacket.

Mick

[eremita]

Thanks for the info.  I am going to measure up a few of the nuts and order the appropriate sockets.  I'll keep a set of seperate tools just for the Listeroid.

Whitworth spanner sizes refer to the diameter of the shank, not the head.  The size across
flats of the Whitworth heads are as below.  From this you will see that you can use an
18mm for 3/8" BSW and a 33mm for 3/4" BSW.  15mm will be a very tight fit on a 5/16" BSW
and for this and the rest you really need to get the proper spanners.  I have no BSF threads on
my original Lister (CD) but the hexagonal head sizes are the same for BSW and BSF, only that
BSF uses smaller heads for a given shank diameter.  Most BS spanners are marked with both
BSW and BSF sizes.

A/F in.  A/F mm.  BSW     
     
0.34     8.6     1/8"
0.445   11.3     3/16"
0.525   13.3     1/4"
0.6     15.2     5/16"
0.71    18.0     3/8"
0.82    20.8     7/16"
0.92    23.4     1/2"
1.01    25.7     9/16"
1.1     27.9     5/8"
1.2     30.5    11/16"
1.3     33.0     3/4"
1.39    35.3    13/16"
1.48    37.6     7/8"
1.575   40.0    15/16"
1.67    42.4     1"
1.86    47.2     1 1/8"
2.05    52.1     1 1/4"

JD

[OffGrid]

Hi Mick,

Thanks for the good info.

The hardware on my engine was so poor it did not have a clean match to either BSW or SAE NC when checked with the respective thread pitch gauges. Pitch angle! no more like bumps and grooves, one stud even had a crack running through it. I agree it is not good engineering practice to mix them up but in this case the NC actually had a better fit with less play. 

[listerdiesel]

There are lots of thread tables on our website, including some other stuff that might be of interest:

http://www.oldengine.org/members/diesel/Tables/Mech1.htm

Peter

[adhall]

If one needs (or even prefers) to use an SAE fastener on one of these engines, I wonder if it would be a good idea to chase the thread on the mating part with an SAE tap or die. That would widen the thread angle to 60 degrees and remove the radius at the top or bottom (depending on whether it's a male or female thread) and should give a better fit. I would be concerned about stress concentrations when different thread forms are mated together. I would think that this is could be a serious concern when one of the threads is in cast iron.

You would want to be very careful to verify the thread pitch first though...

Best regards,
Andy Hall

[xyzer]

Andy,
I wouldn't do that unless it was a last resort. I personally have no problem using an SAE for things like access covers, air cleaner nuts, valve cover nuts, and even maybe intake or exhaust manifolds. These fasteners don't need to be torqued any more than it takes to hold them on there. Any of the rotating assemblies or bearing housings I would stick with whitworth only!
Dave

[adhall]

Dave,

I couldn't agree more with using the Whitworth fasteners if they are available. (Shocking as it may seem, there are reqions of the world where Whitworth fasteners are virtually unknown.  )

The point I was raising is that there appears to be enough "extra" material on the Whitworth thread that it could be converted to an SAE thread by chasing, if necessary. And, yes, now you wouldn't want to use a Whitworth fastener in that spot anymore.

In particular, if I was faced with putting an SAE fastener into a female Whitworth thread and it was in a cast part, I would be very reluctant to do that in any case where the fastener was heavily loaded. On the other hand, if I was forced to do this in an emergency situation, I would rather chase the thread than risk cracking the casting or stripping the thread.

Best regards,
Andy Hall