Sprindle tread chasing - Atlas 618?

[Rex]

I am in the final throes of an Altas 618 restoration. Looks great, install the spindle. Now the threads on the left will not take the ring nut that preloads the bearings, and the chuck won't screw onto the spindle nose &%$*@!!

On disassembly, I had tapped the spindle out (both ways, as required) with light taps of a brass scrap that was on hand. No great force required, but I must have distorted a thread or two in the process. I can only get about half a thread started, yet there is no visible defect that I can find. I have even run a Starret thread gauge around it under a magnifier, but it seems to fit fine all the way around, both ends.
The ring nut threads onto a bolt perfectly. I have nothing to check the chuck internal threads, but they look good and are clean.

So now I need a thread chasing method.
left end is 3/4-16, chuck end is 1"-10 (I think)
Ideally I'd find one of those split thread chasers you can get for wheel studs on a car. I sawed a 3/4-16 nut in two to improvise one, but I think the steel was softer than the spindle, did not work.
I have other lathes, and I set one for the correct thread and tried to chase it with that, but it dug in pretty quickly and I abandoned that idea. Not sure why that didn't work, but I don't want to take a chance on ruining it.

Sure would like to finish this thing.
Anyone got any neat ideas for solving this?

[JCHannum]

A lightly applied three corner file will usually clean up minor buggers on threads. Start one or two threads in and file out. Keep checking with the nut or a female thread.

Rawhide mallets or hard wood blocks are better for removal than brass, there is less of a tendency to roll the threads over.

[Mike Burdick]

Rex,

Since the threads aren't messed up too much you might try using a thread restoring file. Most Hardware or Auto parts stores carry them as well as Enco, MSC, etc., and they cost around $10.00 per each file. Each file has 8 different thread pitches and work very well for fixing threads with minor dings and such. Both, Vermont American and Nicholson make them.

[Rex]

thread files

I am familiar with those, will swing by the warehouse tomorrow and pick up a couple. -Thanx

[IOWOLF]

Imho, get a set Including the metric for a couple bucks more.

[CCWKen]

You shouldn't be hammering on the thing at all. Good way to crack or chip a bearing/race. Or bugger up threads. I made up a simple puller with all-thread, a bushing in the back and a piece of pipe and flat on the front. When you install the bearings, warm them on a light bulb for about 3 minutes and they'll slip right up.