M61, a variant of the M26 (manufactured in May 1969)
|Place of origin||United States|
|Used by||Brazil, United States, Israel, United Kingdom, Australia, Canada, Portugal, South Africa, Pakistan|
|Wars||Vietnam War, Falklands War|
|Weight||16 oz. [454 g]|
|Filling weight||5.75 oz. [164g]|
|M204-series Timed Friction Fuse |
The M26 is a fragmentation grenade developed by the United States military. It entered service around 1952 and was used in combat during the Korean War. Its distinct lemon shape led it to being nicknamed the "lemon grenade".
Fragmentation is enhanced by a special pre-notched fragmentation coil that lies along the inside of the grenade's body. This coil had a circular cross-section in the M26 grenade and an improved square cross-section in the M26A1 and later designs.
The grenades were stored inside two-part cylindrical fiberboard shipping tubes (Container M289) and were packed 25 or 30 to a crate.
The M26 emerges
The M26 was developed as a result of the studies on the Mk 2. Unlike its previous counterpart, its M204A1 fuse creates no tell-tale smoke or sparks when ignited and its powder train is almost silent while it burns down. Its Composition B filler was considered safer than the flaked or granular TNT filling used in the Mk 2.
The M26 series was created after World War 2 to meet criticisms of the Mk. II. The original M26 replaced the Mk. II Fragmentation Grenade as Army standard issue in Korea. (Massive World War 2 production left the Mk. II as limited standard issue with the US Army and US Marines throughout the 1960s and the US Navy until the 1970s). The M26A1 / M61 was the primary fragmentation grenade used by American forces in the Vietnam War.
The M26 series (M26/M61/M57) was replaced by the M33 series grenade (M33/M67) at the tail-end of the Vietnam War.
The M26A1 is an M26 that has the fragmentation coil redesigned to have a square rather than circular cross-section and has deeper serrations to aid in fragmentation. It also added a small Tetryl booster charge on its fuze to completely detonate the explosive filler (displaced to 5.5 ounces because of the added booster charge) and used the updated M204A2 fuze.
The M30 is the practice version of the M26 grenade. It had a cast-iron two-piece oval body with a plastic base plug. The body was embossed with the symbols "RFX55"; it was originally the basis for an experimental hand grenade that was never put into production. It had a filler of 21 grains of black powder and used the M10A3/M10A4 or M204A1/M204A2 series of fuzes. Its body is painted light blue with a brown band across the middle. When the grenade detonated, the overpressure made the plug pop out and released a plume of black smoke caused by the burnt filler.
The M61 is the M26A1 with an extra safety (called the "jungle clip"), a twist of wire attached to the lever. This is to prevent detonations in case the pin is accidentally pulled.
Why this might happen requires a bit of an explanation. The most common method of carrying grenades was by straps on the ammo pouches. If they got the grenade snagged, the grenade's pin might work loose or the lever would break off, detonating it. Another problem was, although official policy forbid the practice as unsafe, soldiers sometimes hung their grenades from their uniform by the levers. (This was probably encouraged by war movies and TV shows in which "cool" characters are seen hanging inert prop grenades from their breast pockets). 
The M62 is the practice version of the M26A1 / M61, but with a larger 5/8-inch fuze well. It has a filler of 37.5 grains of black powder and uses the M228 fuze. Its body and lever are painted blue to identify it as a practice grenade and it has a "jungle clip" like the M61.
The M50 was a "live fire" conversion of the M30 Practice grenade for use on training ranges. It sealed the base plug, used the M204A1 fuze, and replaced the low-explosive black powder filler with high-explosive Composition B. It allowed the training of recruits with greater safety because it lacked the fragmentation coil of the M26 and had a smaller blast radius. This also used up obsolete ordnance by utilizing worn M30 bodies as its base.
The M56 is the M26A1 with a larger 5/8-inch fuze well. It uses the M215 detonating fuse (with a delay of 4–5 seconds) and has a "jungle clip" like the M61. The M215 is similar to the M213 fuse used in the M33-series grenades except it has a curved lever rather than the bent straight lever of the M213.
The M57 is the M26A2 with a "jungle clip" safety attached to the lever.
- United States: The M26 was introduced during the Korean War. It was limited standard issue at the beginning of the Vietnam War and was soon replaced by the M26A1 / M61, M26A2 / M57, and M33 / M67 as standard issue.
- Canada: Canada adopted the M61, but it has since been replaced by the C13 grenade, a Canadian-made version of the M67 grenade.
- United Kingdom: The L2 series is the British version of the M26. It has been almost completely replaced by the L109 grenade.
- Israel: The M26A2 was adopted in Israel as the M26, and is still in use in that country. Its variant added an improved safety fuze in 2012 that will not engage unless the pin is pulled and the safety lever is released.
- Australia: Australia adopted the M26, but it has been mostly replaced by the F1 grenade.
- Pakistan: Used by the Pakistan Army.
- Portugal: Portugal adopted the M26A1 and produced it natively as the M312.
- South Africa: South Africa adopted the M26 and received it as US aid. They later natively manufactured the M963 (which stands for "Model of 1963") - a copy of the M312, the Portuguese version of the M26A1. This had two goals. The first was national security - South Africa didn't want to rely on foreign suppliers that might desert or embargo them if pressured. The second was ease of use - The M312 grenade was used in Angola, a former Portuguese colony. South Africa was fighting in Angola's civil war and giving military aid to factions friendly to them. Therefore, South African forces and their allies could use captured or local-issue grenades and not have to familiarize themselves with them.
- South Vietnam: South Vietnam received the M26 grenade as US aid. Production and sales of the M26 continued to South Vietnam even after the US military adopted the M26A1 / M61 and M33 / M67.
- http://operatormanuals.tpub.com/TM-9-1330-200-12/TM-9-1330-200-120023.htm Training Manual TM-9-1330-200-12 Grenades. Table 1: Authorized Hand Grenades3
- McNab, Chris (2002). 20th Century Military Uniforms (2nd ed.). Kent: Grange Books. ISBN 1-84013-476-3.
- http://www.israelnationalnews.com/News/News.aspx/154626#.UaPin5zi6F1 Learning from Tragedy, IDF Develops Safer Hand Grenade (4/9/2012), Israel National News