Product Introduction
Metric hexagonal flange bolts manufactured to DIN 6921 without serration under the bearing surface. The integrated flange increases the contact area and eliminates the need for a separate washer. Diameters M5 through M20 are stocked, with larger sizes available by order, across property classes 8.8, 10.9, and 12.9 per ISO 898-1. Surface treatments are applied in accordance with service environment requirements.

Material & Mechanical Properties
Produced from medium carbon alloy steel and quench-and-tempered to meet the proof load, tensile, and hardness values of the designated property class. Heat-number traceability is maintained through the manufacturing process, and certified test reports are issued upon request. Class 8.8 and 10.9 cover the majority of medium- and high-strength bolting applications; class 12.9 provides ultimate tensile strength in excess of 1200 MPa.

Geometry & Thread
The hexagonal drive head conforms to standard wrench opening dimensions. The smooth, non-serrated flange face prevents surface marking on coated or sensitive mating parts. Metric coarse pitch thread per ISO 724 accelerates power-tool installation and resists stripping in steel and aluminum substrates. Shank length is partially threaded as standard, with full-thread options available where grip length demands it.

Corrosion Protection
Electrodeposited zinc to ASTM B633 Fe/Zn 5–8 μm is the default finish, with supplementary passivation. For outdoor and aggressive industrial atmospheres (C3–C5 categories), zinc flake, hot-dip galvanized, or zinc-nickel alloy coatings are specified. All coatings are selected to remain below the hydrogen embrittlement threshold for the relevant property class.

Application Suitability
Motor vehicle engine and chassis assembly, pump and compressor housings, structural framing connections, and general mechanical engineering where a compact flange head bolt replaces a bolt-and-washer assembly. The non-serrated flange is particularly suited to joints where surface preservation and uniform clamp pressure are critical.