PM 1030 - First time cutting threads

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Active Member
Dec 29, 2017

Long story short, I cut threads on my PM 1030 for the first time on Saturday. It wasn't as tough as I'd thought it would be.

Long story long....my wife's uncle (an amazing welder - used to work for Department of Highways for the province doing heavy equipment repair) decided to get a scope mount for the rifle he keeps at the camp - there has been a bear around lately. It's an older Savage 340, and he got one of the bolt-on scope mounts that requires 4x holes in the left side of the receiver to be drilled and tapped.

He made a mistake when he measured the bolts - he also didn't have the instructions for the mount, so instead of #8-40 taps and holes, he went with #10-40 taps and holes...he asked me if I had the 10-40 taps, and I did not, so I ordered them in (they cost about $20 for a pair of them with the right sized drill bits) and lent the tools to him while I was away on a military tasking over the summer so that he could do it himself instead of having to wait for me to get back.

He discovered the mistake when he had finished tapping the holes - he literally dropped the screws right through the holes. After kicking himself resoundingly in the butt over it, he started looking around for some #10-40 bolts that he could use.

There is no readily available source of them...it looks like (from my research) that they used to be a regular sized bolt on Singer Sewing machines - and that's about it. Nothing else seems to use them, so he could not find any around.

Enter me - back from the tasking at last, and we had a family turkey dinner out his way on Friday night. We got to talking, and I said I'd have a go at making him some bolts.

I pick up the rifle and the mount from him, bring them home and sit down by the lathe with the manual and look at the threading gears - it took me a bit of figuring, but I got the right gears in the right places, and had a go at making some threads for the first time on the lathe.

The math worked on the gears - the chart is accurate, and I got some 40 TPI threads on the first go.

The first bolt was kinda messy, so was the second, so those were my 'learning' parts. The 3rd and 4th were good, so was the 6th and 7th. We won't talk about bolt #5.

Anyhow, 3 hours later, I was able to screw the mount onto the rifle for him, and tonight I dropped it off. He offered payment, to which I only asked for a second bottle of the 'family blend' of maple syrup from his sugar shack this spring. I think that's a fair price!

On the other hand, it did take me 3 hours to make 4 bolts...so, while it was a good learning process for me, it proved that making a threaded screw is not a cost effective solution for most projects.



H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Dec 31, 2010
In my shop making #10-40 bolts is very precision work. No doubt my lathes are large for that type of work. The experience is had to be rewarding as well as the satisfaction of knowing you can do it. I go along with pstemart that is a stellar win.
Have a good day
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