Fine-tuning. Optimal adjustment for different size workpieces, user-friendly handle positions are specified for self-locking function with zero power and results minimizes nuts, pipes, one-hand adjustment, and anti-pinching guard fingers, and a striking box-joint design features a bi-lateral guide to withstand heavy loads and the gripping removable surface is safe when the teeth are less abrasion. Designed to grip ; Tooth hardness approximately 61 HRC Oil-hardened and tempered chrome vanadium electrosteel construction for strength and durability