Brass made wide flanged hex backnut in 1/2" BSP size ideal for a wide variety of plumbing applications, perfect to use in central heating and hot & cold water supplies. These hexagonal threaded back nuts are very easy to install - simply screw it onto a suitable attachment and these small but robust fittings will do the job. These backnuts are suitable for 1/2" BSP threads and can be tightened by 25mm spanner. The overall width of the backnut is 38mm.