Ebay - Buyer beware

[roy the mechanic]

What was your last emergency? as Rip says, unc And whitworth are so similar most of us could not tell the difference when screwing them together. - The emphasis here is on screwing!

 

[riptragle1953]

Don't say that in a decent forum...... have you not learned?

 

[roy the mechanic]

Hi, Rip, as Oscar Wilde said, "we are two great nations, divided by the same languge" what it means depends on where you come from. Regards, Roy.

 

[ray vinmad]

Wots a languge?

Ray

 

[clevtrev]

I might be being pedantic about 60 year old threads, but it doesn't matter whether it goes in the hole or not, an M6 screw will go in a 1/4" BSF hole, but it's miles undersize & the wrong pitch.
The theory is that when you tighten a nut & bolt it is the flanks that lock it up & do the work. If you have always used 55deg screws before, a 60deg thread will be making a helical line contact until it deforms the ally enough to hold. i.e. it will only lock up on the flank face once the ally has burred over. So don't be surprised if you have to retighten them a few times before they `fit'.

Ray

No need to be pedantic, the precedent has already been set, with the use of
OBA nuts being used on 6mm threads that hold the 3" speedometer to the
machine. As cataloged by KTB, all editions, Bickerstaff, in MPH, and
online.
And there`s an even bigger difference between 60 and 47 1/2 degrees.