The 100889035 Tapped Flange Bolt Set is designed for joining a 3 3/8, 4 1/2 or 4 5/8 inch tapped hole CF vacuum flange to a same size thru-hole CF flange. This bolt set includes (25) 5/16-24 flange bolts that are 1.25 inch in length and (25) 5/16-24 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.