Range of Ceramic Tap Cartridges with 18 teeth on the Spline. 18 Grooves on spline to connect the tap handle. Easily repair your leaking kitchen basin or bath tap with our 18 spline range of tap valves. Quarter turn BSP 1/2" 3/4" With and without a threaded collar. Choose from Small valves to long stem valves used in wall mounted or traditional taps.