The 100889074 Plate Nut Set includes 24 plate nuts for joining thru-hole 4 1/2 inch CF ultra-high vacuum flanges. Plate nuts are the fastest and most convenient method for closing flanges. They require less clearance, assemble with a single wrench, and are a great solution when there is limited accessibility. Assembly time is reduced as the bolts are easier to start and tighten. They also work with less expensive thru-hole CF flanges eliminating the need and cost of tapped flanges. 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.