Screw machining : History

Why is the word "Décolletage" (collar removal) used in French?

Originally (in the 18th century), watchmakers had screws manufactured by turning bars with the same diameter as the head. This was done by removing the "collet" (collar) (same word as the one used to refer to the portion located between the crown and the root of a tooth) in order to obtain the portion to be threaded, thinner than the head.

A history of screw machining :

Originally turned by humans using bows or pedals, lathes were soon powered 
by mountain streams. . 

The first automatic pinion-based lathes appeared toward the mid-19th century. 
Electricity then replaced stream power, and by the end of the 19th century 
"sliding-headstock" bar turning lathes made it possible for the industry to 
diversify its applications. 

The industry's contribution to the World War I effort was significant.

During the second half of the 20th century, the activity flourished in a variety 
of new industries such as the automotive, electrical, electronic, household 
appliance, aeronautics and medical sectors.