ISO-F DN 320 Bolt & Nut Set, for Smooth Thru Holes, Metric M12 x 70 mm Long Bolts, 1.75 mm Pitch, Stainless Steel, Quantity of 12

These nut and bolt sets are for smooth hole flanges and follow ISO-LF standards for flange sizes of NW-200, NW-250. ISO flanged vacuum fittings are commonly used to build process vacuum plumbing and systems for industrial applications. The fittings are quick to assemble using double claw clamps and a centering ring (please see top right figure - click to enlarge). The Viton® centering ring contains a rubber/elastomeric o-ring. The ISO standard sizes for large flanges are NW-63, NW-80, NW-100, NW-160, NW-200, NW-250, NW-320, NW-400, NW-500, NW-630. These vacuum fittings are made of corrosive resistant stainless steel.