Steel all thread rod. This is a one metre length by 10mm width sturdy threaded hollow tube. This can be used down the centre of a lamp base with a hexagonal nut used to fix on one end and a 10mm entry lampholder on the other. 26 TPI (threads per inch). If you need the thread to be half an inch you can add one of our reducers to the end to make the width half an inch. This item has to be sent by courier due to its length . Made in the UK.