Beam Clamps CM Beam Clamps act as a semi-permanent attachment point for manual or electric hoists. STANDARD FEATURES Working load limit up to 10 tons. Suitable for use with powered hoists and chain blocks. Load pin incorporated for load suspension with reduced headroom. Designed to fit flanges of most structural beams. All CM Screwlok girder clamps are factory proof tested and a certification is shipped with each product.