Curved jaw lock-grip pliers with forged clamp head by 50 CR-V, heat treatment ,with hardness of HRC48-52 .The clamp handle punch forming by 45# steel plate with the thickness of 2 mm ,heat treatment ,non slip overlapping curve surface, nickel plating anti-rust processing.BOSI tools new rapid self-locking pliers adopt three even structure , automatic regulation way , thoroughly change the traditional lock-grip pliers fussy adjustment procedure. One adjustment can clamp different sizes and shapes of objects.Jaw clamp force achieves 454 kg.