M10 x 1.5 x 45 mm Coarse Yellow Zinc Class 90 Tensilock Serrated Hex Head Flange BoltFlange bolts have a circular edge under the head that acts like a washer to distribute loads. Standard non serrated flange bolts are also called frame bolts. Flange bolts are used in automobiles to secure outer casings protecting engines and transmissions. In plumbing they secure pipe ends to ensure strong hold regardless of materials in the ducts. Serrated flange bolts have teeth that grip surfaces for a tight hold. In electronics flange bolts hold