These Knipex 250mm Alligator® Waterpump Pliers are manufactured from chrome vanadium electric steel, oil hardened and tempered with smoothly ground jaws, joint faces and an accurately formed box joint with safety stop. The parallelogram-shaped gripping surfaces have specially hardened teeth to 61HRC for positive grip on pipes and nuts. The plastic coated handles have slip guards for extra safety. They also have a 'no-nip' feature which prevents the handles locking together and damaging the user's hands.