Product Summary

Longze High-Performance Hex Flange Nuts are precision-engineered fasteners that combine a heavy-duty hexagonal nut with an integrated, oversized flange base.

Manufactured in Yongnian, China, our flange nuts serve as a one-piece alternative to a nut and washer, distributing clamping pressure across a wider surface area to protect the

base material and bridge enlarged holes. Whether for high-vibration automotive chassis, solar racking systems, or industrial structural frames, Longze flange nuts provide the structural integrity and installation efficiency required for high-volume assembly.

• ✔ Integrated Washer Surface: The broad flange eliminates the need for a separate washer, reducing part count and preventing the nut from "sinking" into softer materials like aluminum or wood.

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• ✔ Aggressive Anti-Vibration Serrations: Our serrated "Whiz" nuts feature sharp, directional teeth on the flange face that bite into the mating surface, providing a mechanical lock that resists loosening under extreme vibration.

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• ✔ Precision-Forged Threads: Cold-forged to exacting DIN 6H or ASME 2B tolerances, our threads ensure consistent torque-to-tension performance and prevent cross-threading during high-speed robotic assembly.

• Standards: DIN 6923 (Metric), ASME B18.16.4 (Imperial), ISO 4161, EN 1661.

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• Thread Range: M3 - M24 | #6 - 1" (UNC/UNF).

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• Property Class: Class 8, 10, 12 | Grade 5, 8 (ASME) | Stainless Steel 304 (A2) & 316 (A4).

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• Flange Type: Serrated (Standard Locking) or Smooth (Surface protection).

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• Surface Finish: Zinc Plated (Clear/Yellow), Hot Dip Galvanized (HDG), Black Oxide, Dacromet, Zinc-Nickel.

Mechanical Properties & Material Standards

• Matching the steel grade to the structural requirements of the transmission line.

• Property Class	Material	Proof Load (min)	Hardness Range	Best Application
  Class 8 / Gr. 5	Medium Carbon Steel	800 - 855 MPa	180 - 302 HV	Solar Racking / General
  Class 10 / Gr. 8	Alloy Steel	1040 - 1060 MPa	272 - 353 HV	Automotive / Heavy Truck
  SS304 (A2)	Stainless Steel	700 MPa	200 - 280 HV	Food Processing / Outdoor
  SS316 (A4)	Stainless Steel	800 MPa	240 - 320 HV	Marine / Chemical

Standard Cross Arm Dimensions

• Common configurations for standard robotic sheet metal welding lines.

• Thread Size (D)	Width Across Flats (s)	Flange Dia (dc)	Total Height (m)	Max Torque (Gr. 8)
  M8 / 5/16"	13 mm / 1/2"	17.9 mm	8.0 mm	35 Nm
  M10 / 3/8"	15 mm / 9/16"	21.8 mm	10.0 mm	70 Nm
  M12 / 1/2"	18 mm / 3/4"	26.0 mm	12.0 mm	120 Nm
  M16 / 5/8"	24 mm / 15/16"	34.5 mm	16.0 mm	290 Nm

Galvanizing & Corrosion Resistance

• Ensuring 30+ years of service life in corrosive environments.

• Surface Treatment	Process	Salt Spray Test	Service Life	Application
  Zinc Plated	Electrolytic	72 - 144 Hours	High	Indoor Machinery
  Hot Dip Galv.	Thermal Bath	500 - 800 Hours	Maximum	Solar PV / Outdoor
  Zinc-Nickel	High-Alloy	1000+ Hours	Extreme	Automotive / Coastal
  Dacromet	Zinc-Flake	500 - 1000 Hours	High	Marine / Engine Parts

Avoid Pitfalls:

• Oversized Tapping for HDG: For hot-dip galvanized nuts, we ensure the threads are tapped over-size (6AZ) to account for the zinc layer, preventing the nut from jamming on the bolt.

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• Hydrogen Embrittlement (Class 10 / Gr. 8): Electroplated high-strength nuts are prone to sudden failure. Longze implements a strict 8-hour baking cycle at 200°C immediately after plating to maintain structural toughness.

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• Serration Sharpness: Dull teeth won't lock. We use high-precision CNC dies to ensure our Serrated Flange Nuts maintain a sharp, aggressive profile that provides a consistent "click-lock" feel.

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Perfect Fit Assembly:

• Matched Flange Bolts: Pair these with our Longze DIN 6921 or ASME B18.2.1 Flange Bolts for a unified, high-torque joint that eliminates the need for separate washers.

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• Surface Protection: If you are mounting onto painted or polished surfaces and don't want scratches, ask for our Smooth Flange Nuts (non-serrated).

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Quality Control & Logistics:

• ISO 9001 Certified: 5-step QC including computerized thread gauge verification, hardness testing, and salt spray analysis.

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• Sea-Worthy Packaging: Packed in heavy-duty 25kg cartons, plastic-lined for moisture protection, and secured on reinforced pallets for export from our Yongnian hub.

• Q: Can you provide fine-pitch flange nuts? A: Yes, we stock M10x1.25 and M12x1.25, as well as 3/8-24 and 1/2-20 UNF fine threads for automotive applications.

• Q: Are these suitable for automatic feeders? A: Absolutely. Our flange nuts are precision-sorted to ensure consistent dimensions, making them compatible with all standard vibratory bowl feeders.