About Us

Two decades of building
what holds things together.

Shanghai Zinsn Industrial has spent twenty years perfecting one thing — the humble industrial screw. From our first export carton in 2005 to today's 500-tonne monthly capacity, we've stayed close to the customer and obsessed about the millimetre.

Shanghai Zinsn manufacturing facility in Haiyan, Zhejiang
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.

Our Haiyan facility houses 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.

30+

Production lines

Cold-headers, thread rollers and finishing equipment running parallel shifts.

500T

Monthly output

Sustained tonnage that scales for full-container-load orders.

Zinsn factory floor in Haiyan, Zhejiang province
Production Flow

From wire coil to carton — every step in-house.

01

Raw Material Intake

SAE 1018, 1022 and 10B21 wire rod, 304/316 stainless wire — sampled and chemically verified before staging.

02

Cold Heading

Multi-station headers form the head, neck and shank in one continuous strike, ensuring grain-flow alignment.

03

Thread Rolling

Flat-die rollers cold-form the thread profile, work-hardening the surface for higher fatigue strength.

04

Heat Treatment

Carburizing and quench-temper cycles in continuous mesh-belt furnaces, hitting target case depth and core hardness.

05

Surface Finishing

Zinc plating (white / yellow / black), phosphating, ruspert, magni or polymer color coating per spec.

06

Sorting & Packing

Optical sorters reject out-of-tolerance pieces; goods are packed in OEM-branded boxes or bulk cartons.

Inside the Factory

A visual tour of how every screw is made.

ISO 9001 quality management certification held by Zinsn
Quality & Certifications

Tested at every gate,
certified at every level.

Zinsn operates an ISO 9001 quality management system. Each lot is checked for dimensions, surface finish, hardness, torque-to-failure and salt-spray performance per the relevant DIN, ISO or ANSI standard.

  • ISO 9001:2015 — Quality Management System
  • DIN, ISO and ANSI thread standard compliance
  • RoHS / REACH compliant coatings
  • Salt-spray cabinet, torque tester, optical micrometer on-site
  • Mill test certificates and SGS reports on request
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 our factory.

We host customer audits and on-site visits year-round. Two hours from Shanghai by car. We'll arrange transport from your hotel.

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