The 100889055 Thru Hole Flange Bolt and Nut Set is designed for joining two thru-hole 4 5/8 inch CF vacuum flanges. This bolt set includes (25) 5/16-24 flange bolts that are 2.25 inch in length and (25) 5/16-24 nuts and washers. Series 88 CF components are joined by inserting a gasket between the two flange faces, then securing the assembly with bolts. Bolts should be tightened diagonally, versus sequentially around the circumference, for a secure vacuum seal. Assembly is cost effective through reuse of components and inch dimensional stubs, sockets, and tubes. The foolproof design provides leak tight joints consistently.