M26 grenade The M26 is a fragmentation hand grenade made by the United States . Description . 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 . History . 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 . Use . 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 . Replacement . The M26 series ( M26 / M61 / M57 ) was replaced by the M33 series grenade ( M33 / M67 ) at the tail - end of the Vietnam War . Variants . M26A1 . 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 . M26A2 . The M26A2 is an M26A1 modified to accept an M217 impact fuze . It is slightly fatter than the M26A1 and has a red - painted lever that is embossed with the word " Impact " on it . M30 . 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 . M61 . 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 ) . M62 . 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 . M50 . 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 . M56 . 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 . M57 . The M57 is the M26A2 with a " jungle clip " safety attached to the lever .