educate me !!

Ellis Kinney · May 19, 2022

Trying to fix a drill press. Model name Cummins. I purchased it off a truck in a motel parking lot sometime in the 70's. It has been a good drill press although I think probably made in China, not sure. The handle that tightens the table to the column is broken and I need the new bolt piece that locks it down. The problem is the thread size/pitch. I assume it is metric. A 1/2-13 screws on three threads and stops. The metric equivalent does the same thing. I have tried at various hardware stores, Home Depot, and Tractor Supply. Any suggestions? Thanks, Ellis

Dieseltech · May 19, 2022

Find the closest fitting tap and rethread it for a bolt you have available.

Fawteen · May 19, 2022

Go by Home Depot (or wherever) and drop a couple of bucks on a metric thread pitch gauge. Then you'll know exactly what you need.

Janicholson · May 19, 2022

M12 can be 1.25, 1.5, 1.75 pitch all are available 1.5 might be it. Jim

wore out · May 19, 2022

(quoted from post at 10:52:59 05/19/22) Trying to fix a drill press. Model name Cummins. I purchased it off a truck in a motel parking lot sometime in the 70's. It has been a good drill press although I think probably made in China, not sure. The handle that tightens the table to the column is broken and I need the new bolt piece that locks it down. The problem is the thread size/pitch. I assume it is metric. A 1/2-13 screws on three threads and stops. The metric equivalent does the same thing. I have tried at various hardware stores, Home Depot, and Tractor Supply. Any suggestions? Thanks, Ellis

If you have a digital caliper, set it to "metric" and measure between two thread crests or valleys, the result in millimeters will be the metric thread "pitch".

Or, to possibly make it easier, measure between 10 threads and divide the result by ten.

Mike(NEOhio) · May 19, 2022

I have one, Cummins-Mack, China made. Some threads are metric and some Imperial.

4wdtom · May 19, 2022

Ahh, the land of almost right again.

rrlund · May 19, 2022

Sound like an Oliver 500. LOL
They use British Standard threads. The thread count is the same, but the depth is different. All you have to do on those is run a standard tap in the hole.

Duner Wi · May 20, 2022

I looked at my Packard made in Taiwan and pretty sure what you have is 1/2' X 12 TPI which is British Standard Whitworth. Old British Motorcycle store or British printing press from way back.
There are places in USA that deal in British fasteners.

Russ from MN · May 20, 2022

I have set of taps and dies that are so old the 1/2 is 12 tpi. I inherited it from my dad, he got it from an uncle. I think 12 tpi used to be common in the US, we had some old equipment in the paper mill that had 1/2x 12 bolts.

Duner Wi · May 20, 2022

Interesting, thank you.

educate me !!

Ellis Kinney

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Dieseltech

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Fawteen

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Janicholson

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wore out

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Mike(NEOhio)

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4wdtom

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rrlund

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Duner Wi

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Russ from MN

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Duner Wi

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