Bolts
Flange Bolts & Flange Nuts Manufacturer, Wholesaler, Supplier & Exporter
Flange bolts and nuts have an integrated washer face that spreads clamping load and, in serrated versions, bites into the mating surface to resist loosening — eliminating a separate washer. We manufacture and export these to DIN 6921 / DIN 6923.
Flange bolts and nuts exist to solve a simple problem more cheaply than a washer does: distributing clamping force over a wider bearing surface without adding a separate part to the bill of materials. That's a meaningful saving at automotive and agricultural-machinery production volumes, where every eliminated component also removes a step from the assembly line.
The serrations under a serrated flange bolt's head aren't decorative — they bite into the mating surface as the fastener is torqued down, adding genuine locking resistance. But that only works against a softer or coated surface; against hardened or highly finished surfaces, the serrations can't dig in and the locking benefit largely disappears, which is why non-serrated flange fasteners are still specified for finished or hardened joints.
Minimum Order — Container Quantity (Approx.)
A standard 20ft container (~20 tons) holds approximately 500,000-700,000 sets of flange bolts/nuts in common sizes (M8-M10). Exact quantity depends on size and grade and is confirmed at quote time.
You don't need a full container to order. Hurain Engitech & Trade — the group Global Fasteners Exports operates under — regularly ships smaller, partial-container (LCL) orders of just a few pallets or boxes for buyers who don't yet need FCL volume, consolidated with other cargo to keep freight cost reasonable.
Specifications
Standards
DIN 6921 (flange bolts), DIN 6923 (flange nuts).
Types
Serrated (locking) and non-serrated flange bolts/nuts.
Size range
M5 to M20 metric.
Grades
Property class 8.8 and 10.9; stainless A2/A4 on request.
Applications
Automotive assembly
Engine, transmission, and chassis fastening where a wide bearing surface is needed.
Agricultural machinery
Equipment subject to vibration and dynamic loads.
General machinery
Reduced-part-count assemblies replacing bolt + washer combinations.
Materials Available
Steel
Corrosion-resistant
Serration geometry and clamp-load performance are checked against DIN 6921/6923 tolerances before packing.
How We Manufacture & Export This Product
- 1
Spec confirmation
Confirm serrated vs non-serrated, grade, and size.
- 2
Cold forging
Integrated flange forming in a single cold-heading operation.
- 3
Heat treatment
Quench and temper to the specified property class.
- 4
Export packing
Bulk cartons, palletized for container loading.
Export Track Record
Supplied in bulk to automotive component and agricultural machinery manufacturers.
Real-World Use Cases
Automotive engine and chassis assembly
High-volume fastening where the integrated flange replaces a separate washer.
Agricultural machinery
Vibration-prone equipment joints benefiting from the serrated flange's locking action.
General machinery reducing part count
Assemblies where eliminating a separate washer simplifies both the bill of materials and the assembly line.
Common Mistakes Buyers Make
Expecting serration locking on a hardened surface
Serrations need to bite into a softer mating surface — they add little locking benefit against hardened or highly finished steel.
Substituting a standard bolt plus washer without checking clamp area
A flange bolt's integrated bearing surface is engineered to a specific diameter — a standard bolt and generic washer may not match it.
Reusing serrated flange fasteners after removal
The serrations can dull or flatten after one torque cycle, reducing locking performance on reinstallation.
Glossary of Terms
- Serrated flange
- A flange bolt or nut head with radial grooves that bite into the mating surface for added locking resistance.
- Integrated washer face
- The flange itself, which spreads clamping load the way a separate washer would.
- Non-serrated flange fastener
- A flange bolt or nut without locking serrations, used where a smooth bearing surface is required against a finished or hardened joint.
Quality Inspection We Perform
Dimensional inspection
Thread gauge, length, diameter, and head/drive geometry checked against the specified standard.
Material verification
Grade and material composition confirmed against the order specification, with mill test certificates on request.
Mechanical testing
Tensile strength, hardness, and proof-load testing on sample batches, particularly for structural and high-tensile grades.
Finish & coating check
Plating thickness, galvanizing coverage, or passivation quality inspected before packing.
HS Code & Customs Classification
Most fasteners fall under HS Chapter 73 (articles of iron or steel) or Chapter 74/76 for brass and aluminum items — the exact 8-10 digit subheading depends on the specific product and material. We include the HS code on the commercial invoice; confirm the applicable import duty with your customs broker, since rates vary by country and trade agreement.
Packaging & Export Labeling
Export packing is chosen to survive ocean freight and container loading without corrosion or damage: corrosion-protected paper or oil coating where needed, then cartons, drums, or bulk bags, palletized or crated for the container. We can match specific labeling, barcoding, or carton-marking requirements for OEM and repeat buyers.
Countries We Export Flange Bolts & Flange Nuts To
View all markets →Buying guide
How to Choose a Reliable Flange Bolts & Flange Nuts Manufacturer, Wholesaler, Supplier & ExporterWhen serrated flange fasteners actually add locking value, when they don't, and what to check before a bulk automotive or agricultural machinery order.
Frequently Asked Questions
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