How much does a rolled edge or wire filled roll finished edge increase the strength of a piece of armor as opposed to just a plain file smoothed edge. Say for instance on a set of knee or elbow cops. I am thinking that the rolled edge looks better and probably wont "bite " into the wearer when struck . I was also thinking it would help resist impact deformation, but I'm wondering to what degree? Is the additional strength worth the extra labor/ cost? And under the right circumstances can one get bye using 16ga steel with rolled edges in place of heavier gauge steel to save weight and increase mobility ? I'm thinking this works on the same sort of principal as corrugated metal roofing or corrugated cardboard.

Jens

Jens, yes edge rolling does increase strength. Edge rolling over wire even more so and counter sinking a rolled edge increases the strength even more. These techniques introduce geomtric shapes to incease strength vs. simply using thicker material so it can be and was used to help reduce weight while maintaining protection.On certain parts edge rolling also insures the safety/comfort of the wearer as in the openings for arm and neck of breast and back plates and of the top lame of a gorget.

Allan,

That is perfect. I think I might copy that and use it whenever someone asks that question it seems textbook like. (of course I will add Jean comment as well)

RPM

Steve, the border of your sallet helm is counter sunk, also known as "sunken bordering". When you roll an edge, follow it around after with a chissel (sp) a short distance in (3/16" - 1/4" or so) so that the rolled edge, rather than being "underneath" becomes pronounced . I hope that made sense.

Randal, feel free, theres a great article in the first ARS journal about the history of glancing angles, ( ridging and things like that, again using geometry to make a stronger product) in medieval armour thats worth the read.

Bingo!