Tubular props are rigid tubes approx. 38mm in diameter which can be extended in height by addition of interlocking extension props. Interlocking extension props are useful to interlock and extend the height of our tubular props. They can also be used individually or together to form small but stable prop columns. Available in 13mm or 25mm height plus interlock. Tubular Collars/Bases may be used at the top (collar) and base of a tubular prop columnat the junction with the kiln shelf to spread the load. Especially useful with heavy shelf loadings. Castellated props are turreted props approx. 38mm dia. which interlock to form a very stable propping system. Available in 25mm or 38mm extension height. Castellated discs are used at the junction of prop column and shelf to spread the load. Approx. 76mm dia. x 13mm thickness x 6mm effective thickness.