The 100889125 Double-Sided Flange Bolt and Nut Set is designed for joining 2 1/8 or 2 3/4 inch thru-hole or tapped CF vacuum flanges. This bolt set includes (25) 1/4-28 double-sided flange bolts that are 1.75 inch in length, (25) 1/4-28 nuts, and (25) 1/4-28 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.