The Projector, Infantry, Anti Tank (PIAT) Mk I was a British man-portable anti-tank weapon developed during the Second World War. The PIAT was designed in 1942 in response to the British Army's need for a more effective infantry anti-tank weapon and entered service in 1943.
The PIAT was based on the spigot mortar system and projected (launched) a 2.5 pound (1.1 kg) shaped charge bomb using a cartridge in the tail of the projectile. It possessed an effective range of approximately 115 yards (105 m) in a direct fire anti-tank role and 350 yards (320 m) in an indirect fire role. The PIAT had several advantages over other infantry anti-tank weapons of the period, which included an absence of back-blast which might reveal the position of the user and simple construction; however, the type also had some disadvantages, powerful recoil, a difficulty in cocking the weapon, and problems with ammunition reliability.