Single-edged blades with a ridge

[GePi]

Originally Posted by bookandswordblog

It seems like T-sections were popular from the Ottoman Empire to India in the 18th and 19th century? I wonder how they made them because that shape can be a pain to grind and polish.

Blades with a ridge a bit forward of the spine remind me of a classic five-sided katana blade. I don't understand blade engineering well enough to understand why katanas have that section. Guillaume Stanislaus Marey-Monge thought it made for good cutters.

The katana's five side blade geometry goes back to the earliest sabres and proto sabers from the Eurasian steppe peoples, possibly travelled from there to Japan via China.
My pet theory is, that it is the natural shape you arrive at when turning the concept of a diamond shaped double edged blade into a single edged blade, keeping it quite robust while reducing its weight.

Another weapon type I can think of with t-spine section are pichak knifes from Central Asian Turkestan.