# List of Japanese World War II navy bombs

This is a complete list of all aerial bombs used by the Imperial Japanese Navy during the Second World War.

## Types

The Japanese navy produced a large number of different types of bombs, these were sub-divided into three main categories:
* Land bombs - for use against land targets. They were normally not produced to a high standard consisting of a simple cylindrical case, riveted or welded to a cast steel nose.
* Ordinary bombs - for use against ships. They were produced in general purpose and semi-armor-piercing types. They were of higher quality and generally had a smooth machined case
* Special bombs - for various purposes.

## Color coding system

| Bomb type/ mark | Marking scheme | Marking scheme | Marking scheme | Marking scheme | Alternate marking scheme | Alternate marking scheme | Alternate marking scheme | Alternate marking scheme | Purpose |
| Bomb type/ mark | Nose color / band color | Body color | Tail color | Body band color | Nose color / band color | Body color | Tail color | Body band color | Purpose |
| Land | Green | Grey | Green | Blue | Green / Blue | Grey | Grey | - | Land targets. |
| Ordinary | Green | Grey | Green | - | Green / Blue | Grey | Grey | - | Ship targets. |
| Dummy | Green / Black | White | White | - | | | | - | Dummy bomb |
| Practice | Green | Black | White | - | Green / Black | White | White | - | Training. |
| Training | Black overall | Black overall | Black overall | Black overall | - | - | - | - | Training. |
| Smoke | Green / Black | Grey | Grey | - | - | - | - | - | For concealing ships. |
| Mark 1 | Green / Yellow | Grey | Yellow | - | - | - | - | - | Chemical gas bomb. |
| Mark 2 | Blue | Grey | Blue | - | Green / Blue | Grey | Grey | - | Anti-submarine. |
| Mark 3 | Silver | Grey | Silver | - | Green / Silver | Grey | Red | - | For air-to-air bombing. |
| Mark 4 | Green / White | Grey | Red | - | - | - | - | - | Rocket bomb. For dive bombing capital ships. |
| Mark 5 | Green / White | Grey | Grey | - | - | - | - | - | Armor-piercing bomb. For use against capital ships. |
| Mark 6 | Green / Red | Grey | Red | - | - | - | - | - | Incendiary. |
| Mark 7 | Green / Purple | Grey | Purple | - | - | - | - | - | Bacillus bomb. |
| Mark 8 | Green / Brown | Grey | Grey | - | - | - | - | - | Anti-shipping skip bomb |
| Mark 19 | - | - | - | - | - | - | - | - | Special bomb used by fighters against bomber formations, redesignated as Mark 28 |
| Mark 21 | Green / Brown | Grey | Grey | - | - | - | - | - | Cluster of small bombs |
| Mark 22 | - | - | - | - | - | - | - | - | Cluster of spike bombs |
| Mark 23 | Green / Brown | Grey | Grey | - | - | - | - | - | Time delay bomb |
| Mark 24 | - | - | - | - | - | - | - | - | Cluster of parachute bombs |
| Mark 25 | - | - | - | - | - | - | - | - | Cluster of wedge bombs |
| Mark 26 | - | - | - | - | - | - | - | - | Unproduced time bomb design. |
| Mark 27 | Green / Silver | Grey/Red | - | - | - | - | - | - | Phosphorus rocket bomb for use against bomber formations. |
| Mark 28 | Green / Brown | Silver | Red | - | - | - | - | - | Rocket type bomb 10 kg high-explosive. |
| Mark 31 | Grey | Grey | Grey | - | - | - | - | - | Land type bomb. Uses an influence fuze. |

## Bombs

| Designation | Type | Weight | Content weight | Content type | Construction | Length | Suspension lugs | Nose | Tail | Fuze | Notes |
| No.6 | Land Bomb | 63.5 kg (140 lb) | | Picric acid or later Type 98 explosive (mod 1) | | | | Cast steel | | Type 2 Model 2 mod 0 or mod 1 | Obsolete during the war. Case is similar to the Type 99 No. 6 Mk. 2 |
| Type 97 No.6 | Land Bomb | 56 kg (124 lb) | 23 kg (50 lb) | Picric acid or Type 98 explosive | Welded and riveted 6.4 mm (1⁄4 in) steel | 100 cm (40 in) | Horizontal navy type | Cast steel | 20 cm (7+7⁄8 in) long sheet steel | A-3(a) | Capable of penetrating 200 mm of reinforced concrete |
| Type 2 No.6 Model 5 | Land Bomb | 60 kg (132 lb) (approx) | | Five 7 kg high-explosive bombs with bursting charge | Sheet 1.6 mm (1⁄16 in) steel | 110 cm (42 in) | Horizontal navy type | - | 41 cm (16+1⁄4 in) | A-3 (a) or A-3 (b) | |
| No.25 | Land Bomb | 250 kg (550 lb) | 150 kg (330 lb) | Type 98 explosive | Welded and riveted 6.4 mm (1⁄4 in) steel | 180 cm (72 in) | Horizontal navy type | Cast steel | 93 cm (36.5 in) long sheet steel | A-3 (a), A-3 (b), C-2 (a), C-1 (a) | Designed in 1938, production ceased early in the Second World War |
| Type 98 No.25 | Land Bomb | 241 kg (532 lb) | 96 kg (211 lb) | Picric acid or Type 98 explosive | Welded and riveted 13 mm (1⁄2 in) steel | 180 cm (72 in) | Horizontal navy type | Cast steel | 83 cm (32.5 in) long sheet steel | A-3 (a), A-3 (b), C-2 (a), C-1 (a) | The bomb was used by Japanese forces at the Battle of Midway. Designed in 1937 adopted in 1938. Capable of penetrating 400 mm of reinforced concrete. |
| No.80 | Land Bomb | 800 kg (1,760 lb) | 382 kg (842 lb) | Picric acid or Type 98 explosive | Welded and riveted 13 mm (1⁄2 in) steel | 290 cm (113 in) | Horizontal, two guide studs, and carrying band | Cast steel | 100 cm (41 in) long 3.2 mm (1⁄8 in) steel | A-1 (c), B-3 (b), A-3 (d) | The bomb was used by Japanese forces at the Battle of Midway. The bomb was designed in 1937 and adopted in 1938, and will penetrate 400 mm of reinforced concrete. |
| Type 99 No.25 | Ordinary Bomb | 250 kg (550 lb) | 60 kg (132 lb) | Type 91 explosive (Trinitroanisol) | One piece of machine forged 19 mm (3⁄4 in) steel | 170 cm (68 in) | Horizontal navy type | - | 71 cm (28 in) long 1.6 mm (1⁄16 in) steel | A-3 (a), A-3 (b), B-2 (a) | Designed in 1938 and adopted in 1939, it is capable of penetrating 50 mm of armor. |
| Type 2 No. 50 Model 1 | Ordinary Bomb | 500 kg (1,100 lb) | 67 kg (148 lb) | Cast blocks of Type 98 explosive | One piece of machine forged steel 25 to 191 mm (1 to 7.5 in) thick | 200 cm (78 in) | Horizontal, two guide studs and suspension band | - | 100 cm (39.5 in) long sheet steel | A-3 (f), B-2 (a) | Teardrop shaped |
| No.80 Model 1 | Ordinary Bomb | 830 kg (1,820 lb) | 350 kg (770 lb) | Type 91 explosive | One piece of machine forged steel 19 mm (0.75 in) thick | 283 cm (111.5 in) | Horizontal, two guide studs, and suspension band | - | 120 cm (49 in) long 4.0 mm (5⁄32 in) thick steel | A-1 (c), A-3 (c), A-3 (d), tail: B-3 (b) | |
| No.3 Model 2 | Ordinary Bomb | 32 kg (70 lb) | ? | Picric acid | One piece of machined steel | 84 cm (33 in) | Horizontal stud on either side of the body | - | 33.7 cm (13.25 in) | A-1 (a), A-3 (a) | Teardrop shaped. Obsolete since the early stages of the war. |
| No.6 Model 2 | Ordinary Bomb | 63 kg (139 lb) | 29 kg (65 lb) | Picric acid | One piece of machined steel | 108 cm (42.5 in) | Horizontal stud on either side of the body | - | 43 cm (17 in) | A-1 (a), A-3 (a) | Teardrop shaped. Production ceased sometime between 1940 and 1941, although they continued to be used. |
| No.25 Model 2 | Ordinary Bomb | 253 kg (557 lb) | 103 kg (228 lb) | Picric acid | One piece of machined steel 16 mm (5⁄8 in) thick | 182 cm (71.5 in) | Horizontal, navy type | - | 69 cm (27 in) | A-3 (a), B-3 (a) | Teardrop shaped. The bomb was used by Japanese forces at the Battle of Midway |
| No.50 Model 2 | Ordinary Bomb | 490 kg (1,080 lb) | 207.5 kg (457.5 lb) | Type 98 explosive | One piece of machined steel 102 to 13 mm (4 to 0.5 in) thick | 230 cm (90 in) | Horizontal, two guide studs and suspension band | - | 84 cm (33 in) | A-3 (a), B-3 (a) | Teardrop shaped |
| Type 99 No.6 Mk 2 | - | 64 kg (140 lb) | 39 kg (85 lb) | Type 98 explosive | Cast nose plug welded to a 4.8 mm (3⁄16 in) thick cylindrical body | 110 cm (42 in) | Horizontal, two guide studs and suspension band | - | 53 cm (21 in) | A-3 (a) | A Mod 1 version of the bomb was also produced with a cylindrical steel anti-ricochet attachment spot welded to the nose giving it a blunt profile. |
| Type 1 No.25 Mk 2 Model 1 | - | 259 kg (572 lb) | 144 kg (317 lb) | Type 98 explosive | Cast nose welded to a 6.4 mm (1⁄4 in) thick cylindrical body | 180 cm (72 in) | Horizontal, two guide studs and suspension band | - | 55 cm (21.5 in) followed by a 38 cm (15 in) plywood extension | A-3 (a), B-3 (a) | A Mod 1 version of the bomb was also produced with a cylindrical steel anti-ricochet attachment spot welded to the nose giving it a blunt profile. |
| Type 99 No.80 Mk 5 | Armor-piercing | 744 kg (1,641 lb) | 30 kg (66 lb) | Type 91 explosive | Single piece of machined forged steel 100 mm (4 in) thick at the nose and 51 mm (2 in) at the tail | 243 cm (95.5 in) | Two guide studs and suspension band | - | 110 cm (43+3⁄8 in) | Two B-2 (b) tail fuzes | Tear drop shaped bomb, eight recesses around the nose could allow the fitting of a wind shield if used as a projectile. Adopted in 1941, basically a converted 40 cm AP shell, capable of penetrating 150 mm of armor. |
| Type 2 No.80 Mk 5 | Armor-piercing | 800 kg (1,760 lb) (approx) | 45 kg (100 lb) (approx) | Type 91 explosive | Single piece of machined forged steel | | | - | | Two B-2 (b) tail fuzes | Intended to supersede the Type 99 No.80. Not produced in large numbers. Designed in 1939, and adopted in 1942. |
| Type 3 No.150 Mk 5 | Armor-piercing | 1,500 kg (3,300 lb) (approx) | 91 kg (200 lb) (approx) | Type 91 explosive | Single piece of machined forged steel | | | - | | Two B-2 (b) type tail fuzes | Intended to supersede the Type 99 No.80. Not produced in large numbers. Designed in 1942 and tested in 1944, was in experimental production at the end of the war. |
| Type 3 No.25 Mk 8 model 1 | | 294 kg (649 lb) (approx) | 119 kg (263 lb) (approx) | Type 97 explosive | Cast steel nose, welded to cylindrical body 13 mm (0.5 in) thick | 170 cm (67 in) | Horizontal type navy | Cast steel | 70 cm (27+3⁄8 in) long | A-3 (a) | |
| Type 3 No.6 Mk 23 model 1 | | 65 kg (143 lb) (approx) | 23 kg (50 lb) (approx) | Type 98 explosive or Picric acid | Cast steel nose, welded and riveted to cylindrical body 6.4 mm (0.25 in) thick | 103.5 cm (40.75 in) | Normal type navy | Cast steel with anti-riccochet cone | 47 cm (18+1⁄2 in) inches long | C-2 (a) | |
| Type 4 No.25 Mk 29 | Air-to-air bomb | - | - | Explosive with white phosphorus filled steel pellets | Sheet steel with wooden blocks in the nose | - | - | - | - | D-2(a) fuze | Under development at the end of the war to replace No.25 Mk 3 for use against bomber formations, having a larger explosive charge and less incendiary shrapnel. |
| Type 3 No.25 Mk 31 Model 1 | Airburst | 171 kg (378 lb) | 79 kg (175 lb) | Type 98 explosive | Sheet steel cylinder 13 mm (0.5 in) thick with blunt nose | 160 cm (62 in) | Normal navy type | Blunt steel with flange | 81 cm (32 in) | Type 3 electric firing device B-3(a) | Type 3 fuze triggers the bomb at a height of about 7 meters using an electro optical sensor. |
| Type 3 No.80 Mk 31 Model 1 | Airburst | 718 kg (1,584 lb) | 418 kg (922 lb) | Type 98 explosive cast into blocks | Sheet steel cylinder 14 mm (9⁄16 in) thick with blunt nose | 290 cm (113 in) | Two guide studs and a suspension band | Blunt steel with flange | 100 cm (41 in) | Type 3 electric firing device B-3(b) | Type 3 fuze triggers the bomb at a height of about 7 meters using an electro optical sensor. |
| Type 5 No.25 Mk 33 | Airburst | - | - | Explosive with a layer of cylindrical steel fragments | - | - | - | Rounded with plummet fuze holder | - | Plummet electrical fuze with backup Type 15 model 2 fuze | The bomb uses four retarding drogue plates that are opened by an atmospheric pressure fuze to slow descent and release the all-ways plummet fuze, which is suspended by a twenty-meter silk-clad copper to the main bomb. When the plummet fuze touches the ground the bomb is triggered. |

### Rocket bombs

The Japanese produced a number of bombs with rocket motors installed, intended for air-to-air use against bomber formations, or as armor-piercing weapons. Only two saw service, the Type 3 No.25 Mk 4 armor-piercing rocket bomb, and the Type 3 No.6 Mk.27 air-to-air rocket bomb.
| Model | Weight | Description |
| Type 3 No.25 Mk 4 Mod 1 | 315 kg | Work on this design began in 1935 and production commenced in 1943. 1.9 meters long, the bomb is an armor-piercing design, with a thick forged steel nose. The bomb attained a speed of about 100 meters per second when launched. The principal drawback was the small 3.5-kilogram bursting charge. |
| Type 5 No.1 Mk 9 Mod 1 | 15 kg (33 lb) | An experimental design, intended for use against surfaced submarines. The bomb carried 1 kilogram (2.2 lb) of explosives, and had a velocity of about 230 meters per second. Experiments were conducted in June 1944, and it was adopted in 1945. Production had started at the end of the war, but it had not been used. Capable of penetrating up to 25 mm of armor. |
| Type 3 No.6 Mk 9 | 84 kg (185 lb) | An experimental design, intended for use against landing craft and small ships. The bomb carried 10 kg (22 lb) of explosives, and had a velocity of about 230 meters per second. |
| Type 3 No.6 Mk 27 | 66 kg (145 lb) | An anti-aircraft rocket that replaced the Type 99 No.3 Mk.3 in air-to-air bombing. It consisted of a large rocket motor with a 2.5 kg (5.5 lb) incendiary shrapnel warhead triggered by a clockwork time fuze with an adjustable delay of up to 10 seconds. The rocket had a maximum velocity of around 270 m/s, and the warhead contained 140 iron pellets with white phosphorus embedded in them, these were scattered in a 60 degree cone when the warhead was triggered. The bomb was designed in January 1944 and adopted in February 1945. |
| Type 3 No.1 Mk 28 | 9.1 kg (20 lb) | An experimental anti-aircraft rocket with a 600 g (1.32 lb) high-explosive warhead. Experiments were conducted in late 1944. This rocket used 2 kg of propellent and had a maximum velocity of 400 m/s. |

### Incendiary bombs

* Type 99 No.3 Mk 3
* Type 3 No.6 Mk 3 bomb model 1
* Type 2 No.25 Mk 3 bomb model 1
* Type 98 No.7 Mk 6 bomb model 1
* Type 98 No.7 Mk 6 bomb model 2
* Type 1 No.7 Mk 6 bomb model 3 mod 1
~ Type 45 No.44 Mk 6 bomb model 1

### Gas bombs

* No. 6 Mk 1
* Type 1 No.6 Mk.1
* Type 4 No.6 Mk 1

### Cluster type bombs

* Type 2 No.6 Mk 21 bomb model 1
* Type 2 No.6 Mk 21 bomb model 2
* 1 kg hollow-charge bomb
* 1 kg anti-personnel bomb

### Practice bombs

* 1 kg Practice bomb Mod 2
* 1 kg Practice bomb Mod 3
* No.3 Practice bomb Model 1
* Type 99 No.3 Practice bomb

### Flares

* Type 96 landing flare
* Landing flare
* 5 kg parachute flare Model 2 mod 1
* Type 0 parachute flare Model 1
* Type 0 parachute flare Model 1 mod 1
* Type 0 parachute flare Model 2
* Type 0 parachute flare Model 3 mod 1
* Experimental model 11 parachute flare
* Type 94 float light
* Experimental float light
* Type 94 model 2 float light
* Type 0 model 1 float light

### Smoke floats and markers

* 2 kg smoke float
* 43 kg smoke float
* Type 0 Model 1 sea marker
* Type 0 Model 2 sea marker
* Cardboard type sea marker
* Type 3 No.6 target marker bomb
* Type 2 2 kg target indicator

### Misc

* 2 kg Window (Chaff) bomb

## Fuzes

Japanese Navy bomb fuzes designation system was unknown to the Allies until after the end of the Second World War. As a result, a designation system was created to describe the fuzes as follows. It consists of a capital letter, a numeral and a lower-case parenthetical letter.
The capital letter designates the fuzes type as follows:
* A - nose impact
* B - tail impact
* C - long delay fuze
* D - airburst fuze
* E - protective fuze
The numeral approximates the order in which the fuzes were captured by the allies. Finally the lower-case letter in parentheses indicates the different but similar designs.
Where possible the original Japanese designation is given.
* A-1(a)
* A-1(b)
* A-1(c)
* A-3(a) Type 97 Mk 2 nose fuze
* A-3(b) Type 1 nose fuze model 2
* A-3(c) Type 2 nose indicator
* A-3(d) Type 97 Mk 2 nose fuze Model 1
* A-3(e) Type 3 nose indicator
* A-3(f) Type 2 No.50 Ordinary bomb fuze model 1
* A-3(g)
* A-5(a)
* B-2(a) Type 99 No.25 Ordinary bomb fuze
* B-2(b) Type 99 No.80 Mk 5 Bomb fuze
* B-3(a) Type 15 tail fuze model 2
* B-3(b) Type 15 tail fuze model 1
* B-5(b)
* B-5(c)
* B-6(a) Type 97 rail initiator
* B-9(a) tail fuze
* B-10(a) tail fuze
* C-1(a) Type 99 special bomb fuze
* C-2(a) Type 99 special bomb nose fuze
* D-2(a)
* D-2(b)
* D-2(c)
* D-3(a)
* D-4(a) parachute flare fuze
* Type 3 electric firing device