A bolt (10) for securing timber to any other material, comprises: a bolt head (101) with a series of spiked teeth (102) on its underside; a cylindrical bolt rod (103) extending from the bolt head (101) is threaded and split into two rods (105a,b) at its free end, so as to define a slot (106) therebetween. In use a user drills a hole through pieces of timber to be secured together, and hammers the bolt through the hole. The spiked teeth on the bolt head lock into the timber, securing the bolt at one end. At the free, split end of the bolt rod, a washer and nut are tightened onto the bolt. A cold chisel is hammered into the slot between the split ends of the rod, bending the ends outwards and thus preventing the nut from loosening.