Description
This grenade is manufactured in two sizes. The basic principles of construction are the same in both sizes, but variations occur in weights, measurements and the explosive charge. The grenade consists of a cone shaped explosive charge, a metal cone and a wooden base all contained in a silk bag. A fuze is inserted and a tail attached to the apex of the charge.
The explosive charge is cast in the form of a truncated cone. A metal cone is inserted in the base and in the upper end is a well which receives the gaine of the fuze. Surrounding the gaine is a cast ring pellet. In the large size grenade the explosive is Type 94, and in the small size grenade it is Pentolite (50/50 TNT and PETN). A thin layer of waxed paper surrounds the charge.
At the bottom of the explosive charge is a wooden base which is flat on the top and rounded on the bottom. The hole in the base has a slightly smaller diameter than the hole in the cone.
Covering the charge and base is a silk bag either white or olive drab in color. When the grenade is assembled, a drawstring closes the bottom. A metal ring is inserted over the top of the bag. Inside the top of the explosive charge is fitted an adapter ring which is threaded to receive the fuze. Four screws hold the parts together.
Tied around the top of the grenade is a tail made of hemp to provide stability in flight and to make the grenade strike the tank base first.
The fuze is constructed in two parts which are threaded together. The lower body has external threads for screwing into the adapter ring and internal threads for receiving the gaine. The striker is held in position by a safety pin and creep spring. The under side of the upper body and the top of the striker are curved so that if the grenade strikes at a slight angle the striker will be cammed down.
Functioning
Before the grenade is thrown the safety pin is pulled out. On impact the firing pin overcomes the spring and moves down to pierce the primer. The fuze is not "all-ways action", but will probably function on a slight angle of impact.
A second small grenade has been recovered which is identical to the previously described small grenade in measurements and type of construction but differs in the following details. The silk bag which covers the charge of the second grenade is made of bright yellow finished silk. The main explosive charge is picric acid with a small RDX booster. The adapter ring is bakelite instead of metal, while a straw tail is used in place of hemp. The fuze of the second grenade has a black finish, a single safety pin, and a gaine which is crimped to the fuze body, but otherwise is similar in construction and operation to the fuze of the first grenade.
Hazardous Components
No information about hazardous components.
Physical Data
Diameter at base, large grenade - 4.38 in (111 mm)
Diameter at base, small grenade - 4 in (102 mm)
Length, large grenade - 6.75 in (171 mm)
Length, small grenade - 5.88 in (149 mm)
Length, fuze - 188 in (48 mm)
Weight, large grenade - 2.75 lb (1.25 kg)
Weight, small grenade - 1.8 lb (0.84 kg)
See Also
Nothing else to see.
Source(s)
OP 1667, Japanese Explosive Ordnance, Volume 1 (1946)
Catalog of Enemy Ordnance Materiel (1945)
CINCPAC-CINCPOA Bulletin 55-45, Japanese Infantry Weapons (1945)
