Tested at every gate, certified at every level

Quality in a fastener plant is not an inspection at the end. It is a chain of controls that starts at the wire rod and finishes at the carton seal.

Quality system

What we certify and test

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 and optical micrometer on site
Mill test certificates and SGS reports on request

Quality control laboratory with microscope, torque and hardness testers

Control points

Where quality is actually decided

Each stage carries its own inspection gate — material verification, forming tolerance, case depth and core hardness, coating thickness, and a final optical sort before packing.

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.

Buyer questions

Quality FAQ

Which quality management system do you operate?

Zinsn operates an ISO 9001 quality management system. The certificate is available on request.

What is checked on each lot?

Each lot is checked for dimensions, surface finish, hardness, torque-to-failure and salt-spray performance per the relevant DIN, ISO or ANSI standard.

Can you provide third-party test reports?

Yes. Mill test certificates and SGS reports are available on request, alongside our own lot-level dimensional inspection records.

Are the coatings RoHS and REACH compliant?

The coatings we run are specified as RoHS / REACH compliant, and written confirmation is issued with the order documentation on request.

Documents available on request

See the full document list

Note on certification claims. We publish only the certifications we hold. If your project requires a certification not listed here, tell us before you order and we will confirm in writing whether we can meet it.

Need documentation with your order?

Tell us which certificates and reports your customs broker or specifier requires and we will prepare them with the shipment.

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