The bolt holes in CF flanges are manufactured in two basic configurations: tapped and through hole. Through hole flanges require longer bolts, but are otherwise identical to bolts for tapped flanges. Bolts for both configurations are produced in two basic styles: hex head and 12-point. 12-point bolts require a 12-point (socket) wrench. Through hole bolt kits come with standard hex head nuts or plate nuts. Plate nuts are ideal for applications with minimal clearance. The standard ultra high vacuum seal for a CF flange is a copper gasket. However, reusable Fluorocarbon (FKM) gaskets are available for high vacuum applications. Accessories include: anti-sieze thread lubricant and 12-point wrenches.