First Use of Threads 1

[Binary]

One of my colleagues was wondering aloud when the first threads were used for mechanical fastening, clamping, or positioning.

The first "thread" use I thought of was Archimedes and his screw-pump but he was thinking about threaded fasteners or power screws.

Anybody know?

 

[EnglishMuffin]

I could be wrong, but I have a hunch that many metal screws produced in Roman, and perhaps Greek times were not hand filed as your first link claims, but produced on a lathe, probably using a thread chaser, but possibly something more sophisticated. However, it's just a hunch - I can't prove it. But the more I learn about earlier civilisations, the more I think we underestimate them.

 

[ni1d]

Re: how to make things more accurate starting from less accurate:

In "Foundations of Mechanical Accuracy" published by Moore Tools, there's a nice description of making precision lead screws. The final step is hand lapping.

Laps are devices that average out errors, so if you have a screw with decent overall accuracy but local errors, a lap (skillfully operated) will improve it.