US Bomb, 260 lb Frag, AN-M81
The 260-pound frag bomb AN-M81 has a body constructed of spirally wound 1 inch square steel bar. A seamless steel tube forms the basis for the outer wrapping. The steel bar winding is forged at the nose and tail to form solid nose and tail sections. The 260 pound frag bomb AN-M81 can use either a box type or a conical type fin assembly. The conical type fin (M135) is standard for high altitude and/or high-speed bombing. The nose and tail sections are threaded to accommodate nose and tail fuzes. Two suspension lugs are welded 14 inches apart on one side of the bomb body; a single lug is attached to the opposite side at the approximate center of gravity. The explosive filler comprises approximately 13 percent of the total weight of the bomb.
The 220 pound frag bomb AN-M88 is a later modification of the 260 pound AN-M81. It is lighter because of its thinner windings. Both bombs have the same outside. diameter; however, the smaller explosive cavity of the AN-M81 contains about 5 pounds less explosive filler. The physical characteristics of the two bombs are otherwise similar. The 260 pound frag bomb AN-M81 is more effective for fragmentation effect against materiel than an equivalent bomb load of 500-pound GP bomb, or 20 pound frag bombs. The casualty effect, however, against unprotected personnel by the 20 pound bomb is greater. The AN-M81 frag bomb compares similarly in effectiveness with the AN-M88 frag bomb.
Collaborative Ordnance Data Repository