introduction to products:
White/Blue Galvanized Zinc Plated ISO7380 Hex Socket Button Head Screws are rounded - head fasteners with internal hex sockets. Made from carbon steel (available in strength grades 4.8, 8.8, 10.9, 12.9), the white/blue zinc plating forms a protective layer that enhances rust and corrosion resistance (with blue zinc offering better salt - spray performance than white zinc). The button - head design provides a low - profile, snag - free finish, while the hex socket allows for precise torque control during installation. Compliant with the ISO 7380 standard, they come in sizes ranging from M3 to M24. These screws are widely used in machinery, building structures, automotive interiors, and electronic equipment — scenarios where both aesthetic appearance and secure fastening are required.
Instructions for Use:
Install the screws using a matching hex socket wrench, tightening them to the recommended torque (avoid over - tightening to prevent thread damage). For maintenance, regularly clean the surface with a dry cloth. If the white/blue zinc plating is scratched, repair it with anti - rust paint in a timely manner. Avoid using the screws in strong acidic environments for long periods to maintain the protective effect of the plating.
| Thread Size | M3 | M4 | M5 | M6 | M8 | M10 | M12 | M16 | |
| d | |||||||||
| P | Pitch | 0.5 | 0.7 | 0.8 | 1 | 1.25 | 1.5 | 1.75 | 2 |
| b | Ref. | 18 | 20 | 22 | 24 | 28 | 32 | 36 | 44 |
| da | max | 3.6 | 4.7 | 5.7 | 6.8 | 9.2 | 11.2 | 13.7 | 17.7 |
| dk | max | 5.7 | 7.6 | 9.5 | 10.5 | 14 | 17.5 | 21 | 28 |
| min | 5.4 | 7.24 | 9.14 | 10.07 | 13.57 | 17.07 | 20.48 | 27.48 | |
| d1 | Ref. | 2.6 | 3.8 | 5 | 6 | 7.7 | 10 | 12 | 16 |
| ds | max | 3 | 4 | 5 | 6 | 8 | 10 | 12 | 16 |
| min | 2.86 | 3.82 | 4.82 | 5.82 | 7.78 | 9.78 | 11.73 | 15.73 | |
| dw | min | 4.97 | 6.66 | 8.41 | 9.26 | 12.48 | 15.7 | 18.84 | 25.28 |
| e ③ | min | 2.3 | 2.87 | 3.44 | 4.58 | 5.72 | 6.86 | 9.15 | 11.43 |
| k | max | 1.65 | 2.2 | 2.75 | 3.3 | 4.4 | 5.5 | 6.6 | 8.8 |
| min | 1.4 | 1.95 | 2.5 | 3 | 4.1 | 5.2 | 6.24 | 8.44 | |
| r3 | max | 3.7 | 4.6 | 5.75 | 6.15 | 7.95 | 9.8 | 11.2 | 15.3 |
| min | 3.3 | 4.2 | 5.25 | 5.65 | 7.45 | 9.2 | 10.5 | 14.5 | |
| r1 | min | 0.1 | 0.2 | 0.2 | 0.25 | 0.4 | 0.4 | 0.6 | 0.6 |
| r2 | min | 0.3 | 0.4 | 0.45 | 0.5 | 0.7 | 0.7 | 1.1 | 1.1 |
| s | Nominal Size | 2 | 2.5 | 3 | 4 | 5 | 6 | 8 | 10 |
| max | 2.08 | 2.58 | 3.08 | 4.095 | 5.14 | 6.14 | 8.175 | 10.175 | |
| min | 2.02 | 2.52 | 3.02 | 4.02 | 5.02 | 6.02 | 8.025 | 10.025 | |
| t | max | 1.2 | 1.65 | 2.12 | 2.26 | 3.05 | 3.75 | 4.61 | 6.19 |
| min | 1.04 | 1.3 | 1.56 | 2.08 | 2.6 | 3.12 | 4.16 | 5.2 | |
| w | min | 0.2 | 0.3 | 0.38 | 0.74 | 1.05 | 1.45 | 1.63 | 2.25 |
| Minimum tensile load(N) | 8.8 ① | 3220 | 5620 | 9120 | 12900 | 23400 | 37100 | 54000 | 101000 |
| 10.9 ① | 4190 | 7300 | 11800 | 16800 | 30500 | 48300 | 70200 | 130000 | |
| 12.9/12.9 ① | 4910 | 8640 | 13900 | 19700 | 35800 | 56600 | 82400 | 154000 | |
| 70 ② | 2820 | 4920 | 7940 | 11300 | 20600 | 32500 | 47200 | 88000 | |
| 80 ② | 3220 | 5620 | 9120 | 12900 | 23400 | 37100 | 54000 | 101000 | |
| Length of Thread b | - | - | - | - | - | - | - | - | |
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 .
















