The 100761363 Flange Bolt Set is designed for joining a size NW630 ISO-BF bolted flange to a size NW630 tapped flange. This set of 304 stainless steel hardware includes (20) M12 threaded 65 mm bolts with 1.75 mm pitch and (20) M12 washers which is what is required to join NW630 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.