An aluminum alloy wire tensioner weighing 0.75 tons with a length of 1.5 meters uses a 5-millimeter lifting chain and has a self-weight of 4 kilograms. The 0.75 ton aluminum alloy hand chain block is a tool for small-scale hoisting tasks, and its lightweight design can reduce physical exertion. Common malfunctions include: 1. Sticking handle: This is often caused by twisted chains and requires loosening the load to straighten out the chain; it should not be forcibly turned. 2. Brake failure: Check the tension of the ratchet spring. For the 0.75 ton model, the elastic threshold of the spring is relatively low (about 15N), which can easily fail due to fatigue.