My new favourite threads

I use metric course threads for most jobs but I have a project at the moment that would benefit from a slightly bigger core diameter so I used M10 x 1. I really dislike making threads by hand much above M8 due to the effort required but cutting this 10 x 1 thread the other day was really nice, even in stainless steel. Thread strength isn’t critical to this application so I think in similar situations I’ll be using fine threads a bit more in the bigger sizes.

I have a m10x1 that I picked up with a bunch of of secondhand taps, dies and holders. So far I have not used it. Will need to try it out. The rest go up to M16, Not really had a problem using this size. The holders were old and needed a bit of fetling, but the taps and dies all seemed unused.

I needed to make up a missing nut for a thermal cutout. Thread was M11 x 1. Tracy tools to the rescue as usual. Tapping drill 10mm and so easy to cut.

10mm x 1mm is a thread often found on electrical fittings, bulb holders Etc. Noel.

I cut a male 10 x 1 thread in some brass for my project and it came out looking so good. I don’t use M12 very often but I’m thinking I should get a fine tap and die in this size. I’m not sure what pitch to get though? Maybe 12 x 1.25?

And brake pipes.

I originally got M10 x 1 for the small CM-6 spark plugs often found on models and have slowly built up a collection of the fine metric threads M4 & 5x0.5, M5x0.5, M6, 7 & 8x0.75, M8, 10, 12 & 18 x 1. They mostly get use for steam fittings, glands etc on the models I deign which are all metric.

The 1mm constant pitch is not far off the old 26tpi which was also an ideal thread where something finer was needed and 0.75mm pitch is close to 32tpi ME but the 0.5 is a bit fine once you get above M5

M10 x 1 is also the thread on the height adjustment for many QCTP tool holders. When I made several new ones I ordered some 10 x 1 electrical nipple 65mm long. It was a godsend not having to thread them all and cut to length from threaded bar. Another aside is that it is virtually the same size as 1/8" BSP so very handy if you do not have the BSP tap.

regards

Since 1/8" BSP has been mentioned M10x1 is also a common grease nipple size, This thread size is more common than some would think ! M10 X1 and M8 X 1 are both very useful sizes in metric. The light etching of sizes on modern taps, dies Etc when one has many sizes that are similar in dia and pitch can easily cause trouble and confusion ! Noel.

Possibly not a coincidence that there are a lot of 26 tpi threads in larger sizes... cycle threads. A very near imperial alternative to 1mm pitch.

Also 32tpi and 40 tpi 'Models Engineer' threads.

Relatively fine constant pitch sizes have practical advantages, especially if cutting a lot using a lathe.

No reason why 0.8 mm and 0.6 mm don't provide practical alternatives for these finer thread forms, if you can get the taps.

Neil

M12 x 1.25 is used on Japanese motorbikes (as is M10 x 1.25).

M10 x 1.0 hydraulic applications as is 3/8 UNF.