You can have confidence in Whitelaw Rigging anchor bolts. In addition to any quality checks required by specification, Whitelaw Rigging also checks each lot for nut fit and major diameter. These checks are recorded on the work order. From time to time we also perform destructive pull tests to verify bolt strength. Below is shown a test chart on a 3/4" grade 55 bolt. On it you can see the load applied, yield area and the ultimate separation. In this case 31613LB. The ASTM F1554 grade 55 required value is 25000LB.   Two different types of threading processes are used at Whitelaw Rigging. Roll threading (shown below left) is a cold forming process where a blank is rolled between hardened steel dies. It wastes no material, provides a smoother finish and is the faster process. Cut threading (shown below right) is the preferred method for special materials, large diameters and short runs. Both methods meet the major specifications.   | 
