Type 97 Grenade

Type 97 Hand Grenade
A Japanese Type 97 grenade, with the safety fork still in place.
Type	Hand grenade
Place of origin	Empire of Japan
Service history
In service	1937-1945
Used by	Imperial Japanese Army  Imperial Japanese Navy
Wars	Second Sino-Japanese War Soviet-Japanese Border Wars World War II Hukbalahap Rebellion Indonesian National Revolution Syrian Civil War
Production history
Designed	1936
Specifications
Weight	0.45 kg (16 oz)
Length	(3.78 in)
Filling	TNT
Filling weight	65 g (2.3 oz)
Detonation mechanism	Pyrotechnic delay 4 to 5 seconds

The Type 97 Hand Grenade (九七式手榴弾, Kyūnana-shiki Teryūdan^?) was the standard fragmentation hand grenade of the Imperial Japanese Army and Imperial Japanese Navy SNLF during the Second Sino-Japanese War and World War II.

The Type 97 was developed from the earlier Type 91 Grenade which could also be used as a fragmentation hand grenade, but was predominately used as munitions for the Type 10, and Type 89 grenade launchers. For this reason, it had less explosive power and a relatively longer delay time than a dedicated manual hand grenade. To address these issues, the Army Technical Bureau developed a new design in 1937.

The Type 97 had the same principles as most of fragmentation grenades of the period: a grooved 'pineapple-shaped' segmented body which dispersed sharp pieces of shrapnel when it exploded. Operation was accomplished by first screwing down the firing pin, so that it protruded from the base of the striker. Then the safety pin was removed by pulling the cord to which it was attached; the protective cap which covered the striker was removed. A sharp blow against a hard surface, such as a rock or combat helmet would overcome a creep spring and crush a thin brass cap, allowing the pin to hit the primer and initiate the delay sequence before throwing at the target. However, in comparison with Allied hand grenades of the period, the explosive force of the Type 97 was weaker and, due to lack of an automatic ignition mechanism, the grenade in practice was found to be unreliable and even dangerous to use because of its inaccurate fuse.