The 100761140 Double-claw Flange Clamp is used to join size NW400 or NW500 ISO-MF vacuum flanges. Series 76 double claw clamps feature stainless steel bolts and washers with two aluminum flange clamp designed for ISO-MF flanges. ISO flanges and seals are designed to be tightened to metal to metal contact. It is important that the clamps or bolts not be over tightened or warping of the flanges could result. The torque rating for clamps and bolts is 7 to 10 pounds per foot.