Seisankaku-Yari 正三角槍 in Koshirae, Kawachinokami Kunisuke 河内守國助 signed, Edo period

This is a yari designed for indoor combat.

The Seisankaku-Yari has an equilateral triangular shape, combining sharpness with durability.
Although the blade is short, the tang is crafted to be very long.
The koshirae is reinforced with iron, making it extremely sturdy.
The blade is secured with three brass mekugi.

The overall length of the yari is short, likely designed with ease of handling indoors in mind.

Translated with DeepL.com (free version)

Signature : Kawachinokami Kunisuke
Nagasa : 119mm (4.69 in.) 
Sori : 0mm (0.0 in.) 
Total length : 980mm (38.58 in.) 
Motohaba : 17.6mm (0.69 in.) 
Sakihaba : 10.6mm (0.42 in.) 
Motokasane : 15.4mm (0.61 in.) 
Sakikasane : 10.4mm (0.41 in.) 
Blade Weight : 248g
Total Weight : 1147g
Tang length : 720mm (28.35 in.)