9" Southbend lathe thread indicator

[JohnEd555]

Hi Guys

I'm new to this Forum and am resident in the UK. I hope you can help!!

I have an old Southbend 9" Workshop Lathe model A and am planning to fit a thread dial indicator to it. I have one on order but I will need to have a set screw to fasten it to the front of the saddle. The threaded hole is there ready but I have no idea what the thread is. Can anyone help? It looks to be about 5/16" dia and I'm sure it's imperial not metric!

Thanks
John

 

[Yan Wo]

Mine is 1/4-20.

 

[michiganbuck]

Should be able to by hand turning to feel the threaad with not harming it.

You can also hand feel a drill in the hole and then look at the tap drill size to get the right idea...
But have caution because someone may have tapped it to some odd thread.

 

[garyphansen]

I believe the older ones had an odd ball thread that is not commonly used now.

 

[kitno455]

Since the thread dial was occasionally an owner installed accessory, we cannot know what thread is used on your lathe. You will need to measure, or frankly, just redrill and tap for something you can acquire more easily.

allan

 

[JohnEd555]

Thanks for your input guys.
I'll have a check with the drill blank but if all else fails I'll re-drill and re-tap with something sensible. The lathe came from my old place of work where I think it had been since new so I guess it's unlikely that the drill had been altered ... but you never know!
Cheers
john

 

[xeddog]

FWIW, My 1952 9A which I believe is all original has a 1/4x20 set screw.

Wayne

 

[Yan Wo]

FWIW, My 1952 9A which I believe is all original has a 1/4x20 set screw.

Wayne

Mine is a 1948 9A. It also has a 1/4-20 set screw and I believe it's original.

 

[pavt]

mine is an original, 1945 9A. It has a 1/4-20 Brass screw.

 

[500mpxlcameraguy]

My 1962 9A is 1/4-20