Haganah - TMT IV Sten markings

[Flying10uk]

Not the toolmaker background that got me interested in Stens. I tend to be interested in 20th century weapons especially WW2 and Cold War from any nation but also have a handful of older ones. When I look at any metal object I automatically visualise in my mind how the item has been made.

Other possible causes for the marks on the Lines Brothers cover could be that the die blocks aren't sufficiently hard enough or haven't been hardened at all which they should have been. Also with a form tool of this type there needs to be a tiny amount of clearance built into the design and so, for example, the Lines simple form tool should have clearance of around .003" per side in addition to the metal thickness. To figure out the width of the punch/top tool of the Lines tool we take the width of the die (=width of cover) minus 2X metal thickness minus 2X clearance (2X.003=.006) = punch/top tool width.

This Sten cover could only really be formed up in a channel type form tool even the type with the welded back as I think the cover is too deep and narrow for normal "off the shelf" bending tools. However, a way round this would be to bend just one side and the base part of the cover with "off the shel" bending tools then weld the other side of the cover on followed by welding the rear part of the cover.