introduction to products:
Stainless Steel Hexagon Socket Head Cap Bolts (DIN 912) are cylindrical-headed fasteners with internal hex sockets, built for precise torque control during installation. Crafted from stainless steel grades — SS201 (budget-friendly for dry settings), SS304 (all-round corrosion resistance for general industry), and SS316 (superior resistance to saltwater, acids, and chemicals for marine/chemical use) — they feature a low-profile design perfect for tight-space installations. Compliant with the DIN 912 standard, they come in sizes from M3 to M64 and lengths of 10mm to 3000mm. Their high-strength construction (e.g., A2-70, A4-70 grades) makes them essential for machinery (die fixturing), electronics (circuit board mounts), automotive (engine components), and aerospace (precision equipment), where secure, compact fastening is critical.
Instructions for Use:
Install using a matching hex socket wrench, tightening to the recommended torque (avoid over-tightening to prevent thread damage)
SS304/316 bolts: Clean regularly with a dry cloth to preserve their natural oxide layer (no extra anti-rust treatment needed).
SS201 bolts: Avoid long-term exposure to damp environments; wipe dry immediately if exposed.
Inspect the head and threads periodically — replace bolts if they show signs of deformation or thread stripping.
| Thread Size | M1.4 | M2 | M3 | M8 | M10 | M12 | (M14) | M16 | (M18) | ||||
| d | |||||||||||||
| P | Pitch | Coarse thread | 0.3 | 0.4 | 0.5 | 1.25 | 1.5 | 1.75 | 2 | 2 | 2.5 | ||
| Fine thread pitch-1 | - | - | - | 1 | 1.25 | 1.25 | 1.5 | 1.5 | 1.5 | ||||
| Fine thread pitch-2 | - | - | - | - | 1 | 1.5 | - | - | 2 | ||||
| dk | plain head | max | 2.6 | 3.8 | 5.5 | 13 | 16 | 18 | 21 | 24 | 27 | ||
| knurled heads | max | 2.74 | 3.98 | 5.68 | 13.27 | 16.27 | 18.27 | 21.33 | 24.33 | 27.33 | |||
| min | 2.46 | 3.62 | 5.32 | 12.73 | 15.73 | 17.73 | 20.67 | 23.67 | 26.67 | ||||
| da | max | 1.8 | 2.6 | 3.6 | 9.2 | 11.2 | 13.7 | 15.7 | 17.7 | 20.2 | |||
| ds | max | 1.4 | 2 | 3 | 8 | 10 | 12 | 14 | 16 | 18 | |||
| min | 1.26 | 1.86 | 2.86 | 7.78 | 9.78 | 11.73 | 13.73 | 15.73 | 17.73 | ||||
| e | min | 1.5 | 1.73 | 2.87 | 6.86 | 9.15 | 11.43 | 13.72 | 16 | 16 | |||
| k | max | 1.4 | 2 | 3 | 8 | 10 | 12 | 14 | 16 | 18 | |||
| min | 1.26 | 1.86 | 2.86 | 7.64 | 9.64 | 11.57 | 13.57 | 15.57 | 17.57 | ||||
| s | Nominal Size | 1.3 | 1.5 | 2.5 | 6 | 8 | 10 | 12 | 14 | 14 | |||
| min | 1.32 | 1.52 | 2.52 | 6.02 | 8.025 | 10.025 | 12.032 | 14.032 | 14.032 | ||||
| max | 1.36 | 1.56 | 2.58 | 6.14 | 8.175 | 10.175 | 12.212 | 14.212 | 14.212 | ||||
| t | min | 0.6 | 1 | 1.3 | 4 | 5 | 6 | 7 | 8 | 9 | |||
| w | min | 0.5 | 0.55 | 1.15 | 3 | 4 | 4.8 | 5.8 | 6.8 | 7.8 | |||
| Weight of per 1000 steel products(≈kg) | - | - | - | - | - | - | - | - | - | ||||
| Length of Thread b | - | - | - | - | - | - | - | - | - | ||||
| Thread Size | (M22) | (M27) | (M33) | M56 | M64 | M72 | M80 | M90 | M100 | ||||
| d | |||||||||||||
| P | Pitch | Coarse thread | 2.5 | 3 | 3.5 | 5.5 | 6 | 6 | 6 | 6 | 6 | ||
| Fine thread pitch-1 | 1.5 | 2 | 2 | 4 | 4 | 4 | 4 | 4 | 4 | ||||
| Fine thread pitch-2 | 2 | - | - | - | - | - | - | - | - | ||||
| dk | plain head | max | 33 | 40 | 50 | 84 | 96 | 108 | 120 | 135 | 150 | ||
| knurled heads | max | 33.39 | 40.39 | 50.39 | 84.54 | 96.54 | 108.54 | 120.54 | 135.63 | 150.63 | |||
| min | 32.61 | 39.61 | 49.61 | 83.46 | 95.46 | 107.46 | 119.46 | 134.37 | 149.37 | ||||
| da | max | 24.4 | 30.4 | 36.4 | 63 | 71 | 79 | 87 | 97 | 107 | |||
| ds | max | 22 | 27 | 33 | 56 | 64 | 72 | 80 | 90 | 100 | |||
| min | 21.67 | 26.67 | 32.61 | 55.54 | 63.54 | 71.54 | 79.54 | 89.46 | 99.46 | ||||
| e | min | 19.44 | 21.73 | 27.43 | 46.83 | 52.53 | 62.81 | 74.21 | 85.61 | 97.04 | |||
| k | max | 22 | 27 | 33 | 56 | 64 | 72 | 80 | 90 | 100 | |||
| min | 21.48 | 26.48 | 32.38 | 55.26 | 63.26 | 71.26 | 79.26 | 89.13 | 99.13 | ||||
| s | Nominal Size | 17 | 19 | 24 | 41 | 46 | 55 | 65 | 75 | 85 | |||
| min | 17.05 | 19.065 | 24.065 | 41.08 | 46.08 | 55.1 | 65.1 | 75.1 | 85.12 | ||||
| max | 17.23 | 19.275 | 24.275 | 41.33 | 46.33 | 55.4 | 65.4 | 75.4 | 85.47 | ||||
| t | min | 11 | 13.5 | 18 | 34 | 38 | 43 | 48 | 54 | 60 | |||
| w | min | 9.4 | 11.9 | 13.5 | 19 | 22 | 25 | 27 | 32 | 34 | |||
| Weight of per 1000 steel products(≈kg) | - | - | - | - | - | - | - | - | - | ||||
| 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 .












