Prior to use, inspect the spanner, making sure it is not damaged or defected in any way. Never use worn, cracked or tweaked spanner. Replace them immediately to avoid injury. Pay special attention to the jaws when inspecting pipe spanners. Make sure they are still sharp or they can cause slippage that may lead to injury. Never attempt to straighten a bent spanner. Doing so will only further weaken it. Never use a hammer with a spanner unless the spanner is specifically designed for such a purpose.