
Total production of Mark 1 and slightly modified Mark 1* STEN machine guns was about 100 000.

Some guns featured small folding forward grip. The Mk.1 featured spoon-like muzzle compensator. Sights were fixed, pre-adjusted for 100 yards distance, peep hole rear and blade front. The stock was of skeleton type, made from steel. The gun was fed from left side mounted box magazines. The tubular receiver and the barrel shroud were made from rolled steel. Trigger unit permitted for sigle shots and full automatic fire, controlled by the cross-bolt type button, located in front and above trigger. It was blowback operated, automatic weapon that fired from the open bolt. The first STEN, STEN Mk.I (full official name was 9mm STEN Machine Carbine, Mark 1), was developed in mid-1941.

STEN guns were made not only in Royal Small Arms factory in Enfield other makers included famous British gunmaking company of the time BSA Ltd, as well as Royal Ordnance Arsenal in Fazakerly, England, and Long Branch Arsenal in Canada. Almost 4 millions of STEN guns of different versions were made between 19. It was one of the most crude and ugly and simply, but effective submachine guns of the WW2. Turpin) and from the factory where they worked (Enfield arsenal). The STEN name came out of names of the designers (R.
