introduction to products：
Self-Locking Domed Cap Nuts DIN986 silver gray are specialized fasteners. They feature a domed top that covers the bolt end, presenting a sleek and modern appearance, and a self-locking design (with a nylon insert or deformed thread section) to prevent loosening caused by vibrations. Made of carbon steel (common grades 4.8–8.8) or stainless steel for better corrosion resistance, they undergo a silver gray surface treatment—either silver zinc plating (for excellent corrosion resistance) or silver gray powder coating (for a smooth finish and enhanced durability), suitable for both indoor and outdoor environments where a neutral, industrial look is desired.
Compliant with the DIN986 standard, these nuts are designed to match bolts of corresponding sizes (typically M3 to M24). Their self-locking feature makes them ideal for industrial machinery (exposed components), automotive accessories (external parts), electrical cabinets (enclosure fasteners), and architectural hardware (visible connections), where secure and aesthetically consistent fastening is required.
Instructions for Use：
Select a nut size that matches the bolt (e.g., an M8 nut for an M8 bolt). Hand-tighten the nut onto the bolt until the self-locking mechanism engages—you may need a bit more force as the nylon insert or deformed thread grips the bolt. For final tightening, use a wrench (do not over-tighten, as excessive force can damage the self-locking feature). The domed cap should sit flush against the workpiece to conceal the bolt end.
For maintenance, clean regularly with a dry cloth to remove dirt and debris. If the silver gray coating is scratched, apply a silver gray anti-rust spray to maintain corrosion resistance. Periodically check the self-locking function—if the nut loosens easily, replace it to ensure secure fastening.
| Thread Size | M4 | M5 | M6 | M8 | M10 | M12 | M14 | M16 | M20 | ||||
| d | |||||||||||||
| P | Pitch | Coarse thread | 0.7 | 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 | 2 | ||||
| Fine thread 2 | / | / | / | / | -1 | -1.25 | / | / | 1.5 | ||||
| e | min | 7.74 | 8.87 | 11.05 | 14.38 | 18.9 | 21.1 | 24.49 | 26.75 | 33.53 | |||
| h1 | 5.6 | 6 | 7.5 | 8.9 | 10.5 | 13.5 | 15.5 | 16.5 | 21 | ||||
| h2 | 9.6 | 10.5 | 12 | 14 | 18.1 | 22.5 | 26.4 | 27.5 | 35 | ||||
| m1 | 3.2 | 4 | 5 | 6.4 | 7.8 | 9.6 | 11.7 | 12.5 | 17 | ||||
| m2 | 2.9 | 3.2 | 4 | 5.5 | 6.5 | 8 | 9.5 | 10.5 | 14 | ||||
| r | 2.5 | 3 | 3.5 | 4.6 | 5.8 | 6.8 | 7.8 | 8.8 | 10.8 | ||||
| s | 7 | 8 | 10 | 13 | 17 | 19 | 22 | 24 | 30 | ||||
| per 1000 units ≈ kg | 1.4 | 1.55 | 3.3 | 5.3 | 10.7 | 19 | 26.8 | 37.1 | 111 | ||||
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 .
