Notak

Ainu word for the edge of a sharp tool like a knife.

Mekkashike

Ainu word for the back of a knife, or sword. Also the ridge of a mountain or house.

Kusabi-hi (楔樋)

Japanese term for an irregular hamon sometimes found on spearheads

On weight and balance

In researching antique arms -or any kind of material culture for that matter- it is of paramount importance to actually feel and handle pieces.

Kuhen

Machu for a groove on a blade or arrowhead

Dāo cáo (刀槽)

Qing Chinese for a groove in a saber blade.

Chinese saber with "naginata-hi"

A Chinese waist saber or yaodao / peidao of the first half of the 18th century.

Chinese saber with U-grooves

With twist-core steel and of early liuyedao form. Probably 17th century.