Our range of nylon threaded bush inserts are designed for use with aluminium or steel square box section tubing. The threaded insert can be used with our range of adjustable levelling feet (please click here for details). These bushes are constructed of glass-filled Black nylon with a nickel plated brass threaded insert (also available with a stainless steel threaded insert, please contact us for details). They are available in thread sizes M8 to M24 and are suitable for box section tubing with a 27.5, 36.5, 37.5, 45.5, 46.5 and 47.5mm diameter.