The 100760220 Bored Flange is used for internal welding of 3 inch outside diameter vacuum tube or pipe to a size NW80 ISO-MF vacuum flange. This 304 stainless steel bored flange is infinitely rotatable and is compatible with NW 80 ISO-MF flange clamps or rotatable bolt rings Series 76 ISO-MF components feature a vacuum flanging system for 63 mm to 630 mm fittings with flange dimensions meeting the requirements established by the International Standards Organization (ISO). They function as modular building blocks in vacuum piping systems and are compatible with ISO compliant components from other manufacturers. ISO-MF flanges are “sexless” with the seal on a symmetrical centering ring that interfaces with two identical size ISO flanges. ISO-MF flanges are more compact than ASA flanges, which were designed for pressure and are unnecessarily massive for vacuum use. The Series 76 ISO-MF flanges can be joined to other ISO-MF flanges using double claw clamps, to ISO-BF flanges using a rotatable bolt ring, nuts, and bolts, or to a tapped flange using single claw clamps. Applications ISO universal components include roughing and foreline plumbing, high-vacuum, high-conductance interconnections, modular systems needing frequent modifications, and research laboratories.