Not really up on non-metric fasteners. My tool post on the Myford has socket cap screws that look like M6 but aren't - anyone know what they are likely to be? I'll take one with me to my local nut and bolt place, but might be useful to know anyway
If it's contemporary with the lathe, it's most likely 1/4"BSF, but...
If it's 6mm dia 1mm pitch but not M6 then it'll be 0 BA if it's 6.35 mm dia .907mm/28tpi pitch, it'll be 1/4" UNF if it's 6.35 mm dia .977mm/26tpi pitch, it'll be 1/4" BSF if it's 6.35 mm dia 1.27mm/20tpi pitch, it'll be 1/4" BSW
If it's anything else things could get awkward :-)
Mark Rand RTFM
1/4" UNF (28 tpi) or 1/4" BSF (26 tpi) if coarser than M6 then 1/4 UNC (20 tpi) or conceivably 1/4 Whitworth (also 20 tpi but 55 degrees)
AWEM
Time said he to lash out and spend some money! You raised the question, Robin, about feed screws which was in Thomas and you now raise the question of cap screws. on your Myford which is the Spare Parts lists. Sorry, Robin, but there is a limit to the times for 'freebies'
Norm
On or around 6 Nov 2006 04:30:12 -0800, "Robin" enlightened us thusly:
oooh, can of worms.
british machinery pre-metric is liable to be UNC or UNF, unless it's really old, in which case it's likely to be whitworth or BSF. One that looks like
6mm is apt to be 1/4".the only difference between whit and UNC (for 1/4" dia) is the thread form, they're both 20 TPI - UNC are 60 degrees, whit are 55; the core diameter of the whitworth is slightly smaller. BSF is 26TPI, UNF is 28 TPI.
As far as I know Myfords never used UNC or UNF as these were brought out just post war and before the Automotive industry forced the use of UNF / C onto us.
Another point is that Myfords may well not have been aware that Mr C Columbus had made his important discover at this time
-- Regards,
John Stevenson Nottingham, England.
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I wasn't asking for freebies... went to the shop today with one of my existing bolts and bought some more... forgot to ask what they were!!!
Not sure what the Thomas comment means, mind... :)
Thanks for your help everyone - I would have looked on the Myford parts list, but the 4 way toolpost is obviously an aftermarket part and thus isn't listed...
Have got them replaced now - now I can ruin tools 4 times as fast!!!
Uncle John, Are you suggesting that this Columbus chappie was the one who made gauges?
Said he, thumbing his copy of Pelmanism.
Norm
No, probably that Myfords cut their cap head socket screw threads with a hammer and chisel :-)
Mark Rand RTFM
Mark, Nope,a Standard size- if my memory is holding out but not 'the' standard size. Norm
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