A system is disclosed of making up formwork ties on site from standard components which are supplied. The components comprise length of stock rod, continuously threaded and provided with two diametrically opposed longitudinal slots (5) by means of which the rod may be lockingly engaged for manual rotation. A length of rod (4) threadedly engaged with a tapered member (1) forms a she bolt, the two parts being prevented from relative rotation by keys (6) inserted in the bores formed by the registering slots (5) and internal grooves (3) formed in the tapered member (1). A locknut (8) provided with a cavity (9) maintains the keys (6) in their bores. A connecting member (15) enables ties of any length to be made up from a number of shorter lengths of stock rod. The rod itself may serve other on site purposes such as reinforcement for concrete.