Two decades of building what holds things together
Shanghai Zinsn Industrial has spent twenty years perfecting one thing — the industrial screw. From our first export carton in 2005 to today's 500-tonne monthly capacity, we have stayed close to the customer and obsessed about the millimetre.
Our story
From a Shanghai trading desk to a vertically integrated maker
Founded in Shanghai's Xuhui District, Zinsn started as a focused exporter of fasteners to the European DIY market. As demand grew and customers asked for tighter specifications and faster turnarounds, we invested in our own production base in Haiyan, Zhejiang — the heart of China's fastener industry.
Today the two locations work hand in hand: Shanghai handles commercial, technical and quality liaison with global clients; Haiyan runs cold-heading, threading, heat treatment, plating, sorting and packaging under one roof. We don't broker — we build. That difference shows up in every carton.
The factory
15,000 m² of production in Haiyan, Zhejiang
More than 30 production lines, including multi-station cold-headers, thread-rolling machines, mesh-belt heat-treatment furnaces, electroplating tanks and automated optical sorting cells. Production capacity exceeds 500 tonnes per month across diameters from 2.5 mm to 8 mm and lengths from 13 mm to 200 mm. Materials include 1018, 1022 and 10B21 carbon steel, plus 304 and 316 stainless steel for corrosive-environment applications.
Production flow
From wire coil to carton — every step in-house
Raw material intake
SAE 1018, 1022 and 10B21 wire rod, 304/316 stainless wire — sampled and chemically verified before staging.
Cold heading
Multi-station headers form the head, neck and shank in one continuous strike, ensuring grain-flow alignment.
Thread rolling
Flat-die rollers cold-form the thread profile, work-hardening the surface for higher fatigue strength.
Heat treatment
Carburizing and quench-temper cycles in continuous mesh-belt furnaces, hitting target case depth and core hardness.
Surface finishing
Zinc plating (white / yellow / black), phosphating, Ruspert, Magni or polymer colour coating per spec.
Sorting & packing
Optical sorters reject out-of-tolerance pieces; goods are packed in OEM-branded boxes or bulk cartons.
What we stand for
Three things we won't compromise
Integrity
Material grade, hardness and dimensions match what's on the spec sheet — every time, every container.
Partnership
We grow with our customers. Many of today's accounts started with a single sample carton fifteen years ago.
Continuous improvement
Every quality complaint becomes a corrective action and a process update. The bar only ever moves up.
Visit us
We host customer audits year-round
The Haiyan plant is two hours from Shanghai by car and is open for customer audits and on-site visits throughout the year. Tell us when you are in China and we will arrange transport from your hotel.
