Twenty years on one product: the screw
Zinsn shipped its first export carton in 2005. Capacity is now around 500 tonnes a month, and the focus is still on dimensions and finish.
How the business grew
The company began in Xuhui District, Shanghai, selling fasteners into European DIY chains. As buyers asked for tighter tolerances and quicker delivery, Zinsn built its own production base in Haiyan, the centre of China’s fastener cluster.
Now the Shanghai office handles sales, engineering questions and quality contact with customers, and Haiyan does heading, rolling, hardening, plating, sorting and packing in one place.
Zinsn manufactures rather than brokers.
The Haiyan plant
| Floor area | 15,000 m² |
| Lines | 30+ (headers, thread rollers, mesh-belt furnaces, plating tanks, optical sorting) |
| Output | 500+ t per month |
| Diameters | 2.5 – 8 mm |
| Lengths | 13 – 200 mm |
| Steels | SAE 1018, 1022, 10B21 carbon; 304 and 316 stainless |
Six steps, all in-house
1 · Wire intake
Rod is sampled and checked chemically
2 · Heading
Head and shank formed in one strike
3 · Rolling
Flat dies cold-form the thread
4 · Hardening
Case depth and core hardness
5 · QC lab
Microscope, torque, hardness
6 · Packing
Optical reject, then cartons
Quality system
- ISO 9001:2015 quality management
- Thread standards: DIN, ISO, ANSI
- Coatings meet RoHS and REACH
- On-site salt spray, torque tester, optical micrometer
- Mill certificates and SGS reports available
Values
Integrity
Grade, hardness and size match the spec sheet in every container.
Partnership
Several current accounts began with one sample carton around fifteen years ago.
Improvement
Each complaint becomes a corrective action and a process change.
Come and audit us
Haiyan is about two hours by car from Shanghai. Visits run all year and hotel pick-up can be arranged.