1/2" BSPT 300mm Barrel Malleable Iron Black 
Perfect for creating your very own pipe light.
Thread: 1/2" BSP
Thread Pitch: 1.8mm
External diameter: 20.9mm
Please Note: Due to the thread being tapered you will not be able to thread the fittings all the way up the thread and you will see the thread before the fittings.
1/2" BSP (British Standard Pipe) is in fact 20.9mm in diameter and not 1/2" imperial.