introduction to products：
Black Zinc Plated/Black Oxide Carbon Steel DIN 6923 Flange Nuts are hexagonal flange fasteners conforming to the DIN 6923 standard. Made of carbon steel (available in strength grades 4.8, 6.8, 8.8, 10.9), they feature two corrosion - resistant surface treatments: black zinc plating (an electro - galvanizing process forming a thin, lubricious zinc layer for basic rust protection and good solderability) and black oxide (a chemical treatment creating a black oxide film to enhance wear resistance and aesthetic appeal). The integrated flange (with or without serrations) expands the contact area with workpieces, reducing pressure concentration to avoid damage. Serrated flanges further boost anti - loosening performance under vibration, eliminating the need for additional lock washers. Available in metric thread sizes from M5 to M20 (both coarse and fine threads optional), they are widely used in machinery (for vibration - prone components), automotive (in chassis and suspension systems), and construction (for structural connections).
Instructions for Use：
Black Zinc Plated/Black Oxide Carbon Steel DIN 6923 Flange Nuts are installed onto matching bolts. First, ensure the nut’s thread size (e.g., M10), strength grade (e.g., 8.8), and surface treatment (black zinc/oxide) match the bolt; check the integrity of serrations for serrated - flange nuts. Then, screw the nut onto the bolt, align the flange with the workpiece, and tighten using a wrench — avoid over - tightening to prevent surface damage. Serrated flanges are ideal for vibrating environments but may scratch soft surfaces (e.g., plastic), so choose non - serrated versions if necessary. Regularly inspect the coating: repair scratches on black zinc - plated nuts with zinc - rich paint, and touch up damaged black oxide surfaces with anti - rust agents to maintain corrosion resistance.
| Thread Size | M5 | M6 | M8 | M10 | M12 | M14 | M16 | M20 | ||||
| D | ||||||||||||
| P | Pitch | Coarse thread | 0.8 | 1 | 1.25 | 1.5 | 1.75 | 2 | 2 | 2.5 | ||
| Fine thread 1 | / | / | 1 | 1.25 | 1.5 | 1.5 | 1.5 | 1.5 | ||||
| Fine thread 2 | / | / | / | -1 | -1.25 | / | / | / | ||||
| c | min | 1 | 1.1 | 1.2 | 1.5 | 1.8 | 2.1 | 2.4 | 3 | |||
| da | min | 5 | 6 | 8 | 10 | 12 | 14 | 16 | 20 | |||
| max | 5.75 | 6.75 | 8.75 | 10.8 | 13 | 15.1 | 17.3 | 21.6 | ||||
| dc | max | 11.8 | 14.2 | 17.9 | 21.8 | 26 | 29.9 | 34.5 | 42.8 | |||
| dw | min | 9.8 | 12.2 | 15.8 | 19.6 | 23.8 | 27.6 | 31.9 | 39.9 | |||
| e | min | 8.79 | 11.05 | 14.38 | 16.64 | 20.03 | 23.36 | 26.75 | 32.95 | |||
| m | max | 5 | 6 | 8 | 10 | 12 | 14 | 16 | 20 | |||
| min | 4.7 | 5.7 | 7.6 | 9.6 | 11.6 | 13.3 | 15.3 | 18.9 | ||||
| mw | min | 2.2 | 3.1 | 4.5 | 5.5 | 6.7 | 7.8 | 9 | 11.1 | |||
| s | max=nominal size | 8 | 10 | 13 | 15 | 18 | 21 | 24 | 30 | |||
| min | 7.78 | 9.78 | 12.73 | 14.73 | 17.73 | 20.67 | 23.67 | 29.67 | ||||
| r | max | 0.3 | 0.36 | 0.48 | 0.6 | 0.72 | 0.88 | 0.96 | 1.2 | |||
Hebei Duojia Metal Products Co., Ltd. was formerly known as Yonghong Expansion Screw Factory. It has over 25 years of professional experience in manufacturing fasteners. The factory is located in the China Standard Room Industrial Base - Yongnan District, Handan City. It conducts online and offline production and manufacturing of fasteners as well as one-stop sales service business.
The factory covers an area of over 5,000 square meters, and the warehouse covers an area of over 2,000 square meters. In 2022, the company carried out industrial upgrading, standardized the production order of the factory, improved the storage capacity, enhanced safety production capacity, and implemented environmental protection measures. The factory has achieved a preliminary green and environmentally friendly production environment.
The company has cold pressing machines, stamping machines, tapping machines, threading machines, forming machines, spring machines, crimping machines, and welding robots. Its main products are a series of expansion screws known as "wall climbers".
It also produces special-shaped hook products such as wood tooth welding sheep eye ring screws and machine tooth sheep eye ring bolts. In addition, the company has expanded new product types from the end of 2024. It focuses on pre-buried products for the construction industry.
The company has a professional sales team and a professional follow-up team to safeguard your products. The company guarantees the quality of the products it offers and can conduct inspections on the grades. If there are any problems, the company can provide professional after-sales service.
Our export countries include Russia, South Korea, Britain, France, Germany, Italy, Canada, Mexico,Brazil, Argentina, Chile, Australia, Indonesia, Thailand, Singapore, Saudi Arabia, Syria, Egypt, Tanzania.Kenya and other countries. Our products will be spread all over the world!
WHY CHOOSE US?
1.As a factory-direct upplier,we eliminate middleman margis to offer you the most competitive pricing for high-quality fasteners.
2.our factory pass the ISO 9001 and AAA certification .we have the hardness testing and the test of zinc coating thickness for galvanized products.
3.with full contrl over production and logistic,we guarantee on-time delivery even for urgnt orders .
4.our engineering team can customize faseners from prototype to mass production , including unique thread designs and anti-corrosion coatings.
5.From carbon steel hex bolts to high-tensile anchor bolts ,we provide a one-stop solution for all your fastener needs.
6.If any defect is found ,we’ll reship replacements within 3weeks of our cost .
