The 100761340 Flange Bolt Set is designed for joining a size NW400 or NW500 ISO-BF bolted flange to a size NW400 or NW500 tapped flange. This set of 304 stainless steel hardware includes (16) M12 threaded 60 mm bolts with 1.75 mm pitch and (16) M12 washers which is what is required to join NW400 or NW500 vacuum flanges. Series 76 ISO-BF flanges and seals are designed to be tightened to metal to metal contact. It is important that the bolts not be over tightened or warping of the flanges could result. The torque rating for flange bolts is 7 to 10 pounds per foot.