A flange nut is a nut that has a wide flange at one end that acts as an integrated washer. This serves to distribute the pressure of the nut over the part being secured, reducing the chance of damage to the part and making it less likely to loosen as a result of an uneven fastening surface. These nuts are mostly hexagonal in shape and are made up of hardened steel and often coated with zinc.
The flange may be serrated to provide a locking action. On a serrated flange nut, the serrations are angled such that they keep the nut from rotating in the direction that would loosen the nut. Because of the serrations they cannot be used with a washer or on surfaces that must not be scratched. The serrations help in preventing the vibration of the nut from moving the fastener, thus maintaining the holding power of the nut.
Flange nuts are sometimes provided with a swivel flange which helps in creating a more stable structure without affecting the finished product like a serrated flange nut. Swivel flange nuts are mostly used in joining wood and plastic.
A self-aligning nut, also known as a spherical nut or leveling nut, is a type of nut that is used in applications where the fastener is not perpendicular to the surface the nut anchors to. It achieves this action by using a flange nut inside a specially shaped dished-out washer. They are commonly used in the aerospace industry. If this nut were not used the object would have to be spot faced perpendicular to the fastener.
Application : The flange bolts are usually used in vehicle frames, especially in trucks and anywhere a head bolt is required. They feature a nozzle, thereby speeding the assembly while eliminating the washer. They render four times the bearing area than of a standard hex screw.
Types : Types of Bolts. In the Petro and chemical industry for flange connections Stud Bolts and Hex Bolts are used. The Stud Bolt is a threaded rod with 2 heavy hexagon nuts, while the Hex Bolt has a head with one nut. Nuts and head are both six sided.
Size : M8, M10, M12, M16, M20
Specification : DIN 6921
Finishing : Zinc (yellow, white, blue, black), black oxide, Geometry, Dacroment, anodizing, nickel plated, plated zinc-nickel, Stainless steel: Passivated Self-Colour, Hot Dip Galvanised (HDG), Bright Zinc Plated (BZP), Sherardized, Stainless Steel, Mechanically Applied coating and some special one like DACROMET
Grade : A2-70, A4-70, A4-80