Locking vertical plate clamp locking plate clamp safely lifts plate and sheet material in the vertical position. Clamp features a spring-loaded locking mechanism for optimum safety, as operator simply pulls ring to allow easy material release. Clamp features a safety mechanism that ensures the clamp does not slip when lifting force is applied or when load is lowered. Forged steel head and gear with hardened carbon steel serrated jaws for long life. Durable powder coat finish. Meets asme b30.20 specifications. Note: not designed to use on stainless steel or aluminum plates. For use only with materials with a surface hardness below hrc 30 hb 300, brinel 1300.