Automotive Fastener Manufacturer

Justwintec is an automotive fastener manufacturer in China, supplying precision screws, bolts, rivets, pins and custom parts for vehicle assemblies, components and automotive hardware systems.

Precision Automotive Fasteners with Full-Process Quality Control

Automotive fasteners require stable dimensions and reliable thread fit. We control every stage from raw material inspection to final delivery, helping you reduce assembly failures, rejected parts and batch-to-batch variation.

For applicable automotive fasteners, dimensional tolerances can be controlled within ±0.05 mm.

We offer a range of significant benefits:

fastener wire material diameter check

01.Stable Control of Raw Materials Across Every Batch

You receive fasteners with more consistent head size, shank diameter, length and thread dimensions, reducing fit and assembly problems.

How we achieve it:

  • Critical automotive parts are handled by skilled operators with more than 15 years of production experience.
  • Incoming wire is checked for diameter tolerance, roundness and surface defects.
  • Unqualified raw materials are rejected before production.
  • Material samples are retained by batch, with heat numbers and batch numbers recorded for traceability.
  • All incoming metal wires are supplied with official Material Test Certificates (MTC)
  • Raw material hardness & spectral sampling inspection is mandatory before product

02. Lower Risk of Dimensional Changes Caused by Mold Wear

Regular tooling control helps prevent thread shape, outside diameter and forming dimensions from gradually moving out of tolerance during mass production.

How we achieve it:

  • New molds undergo first-piece verification before batch production.
  • Thread rolling dies, punches and other tools are checked regularly for wear.
  • For applicable high-volume products, tooling can be inspected after every 500,000 pieces.
  • Scrapped molds are removed and cannot be reused.
  • Fixtures are calibrated regularly to control concentricity, perpendicularity and other geometric tolerances.
female worker fastener quality control
fastener machine operator production checklist

03. Earlier Detection of Production Variation


1) First-piece inspection before mass production
For every new order, size change, die replacement or material switch, our QC team completes full dimension verification on the first sample. Mass production can only start after the first piece passes all tolerance requirements.

2)During cold heading and forming, inspections are carried out every two hours, covering:

  • Head dimensions
  • Rod diameter
  • Overall length
  • Eccentricity

3)Semi-finished Product Segregation & Anti-Mixing

Management Semi-finished goods are separated in color-coded bins: qualified, defective, pending-inspection and machine adjustment materials,to prevent material mixing

04. More Reliable Thread Fit During Assembly

Thread inspection before and after surface treatment helps reduce damaged threads, incorrect thread profiles and assembly failure.

How we achieve it:

  • Go/no-go gauges are used during thread rolling.
  • Thread ring gauges and plug gauges are used to check thread fit.
  • Damaged threads, irregular threads and thread-angle deviations are identified before shipment.
  • Threads are checked again after zinc plating, Dacromet or other coating processes.

This helps prevent problems such as the go gauge failing after plating.

bulk metal fastener hand inspection
fastener dimensional testing workbench

05. Reduced Deformation After Heat Treatment

Heat-treatment checks help ensure that long screws and bolts remain straight and suitable for assembly.

How we achieve it:

  • Long fasteners are checked for bending and dimensional changes after heat treatment.
  • A straightening process is added when required.
  • Overall length, straightness and thread condition are verified again before the next process.

06. Fewer Defective Parts Reaching Your Assembly Line

All automotive fasteners receive 100% inspection, helping reduce rejected parts, rework and production downtime.

How we achieve it:

  • CCD visual sorting checks threads, outside diameter, length and head recesses.
  • Unqualified parts are automatically removed.
  • Manual secondary inspection is added for critical products.
  • Two-dimensional optical measuring equipment checks concentricity, perpendicularity, complex profiles and other geometric tolerances.
  • Inspection data can be recorded and used to generate traceable reports.
fastener production machine operator panel
Why Choose Us

Core Manufacturing & Service Advantages

Stable production, flexible customization and clear order follow-up help you control quality, cost and delivery.

Professional Expertise

Over 30 years of manufacturing experience and technical knowledge, with practical guidance for product development and production.

Stable Delivery

More than 80 Taiwan-imported production machines support a monthly capacity of over 150 tons.

10,000+ m² Self-Owned Factory

Factory advantage: 10,000㎡ self-owned factory, direct manufacturer, cost & lead time controllable.

Full-Process Quality Control

Quality is controlled from raw material inspection and production to packing and shipment.

One-Stop Export Service

6 years of export experience, supporting quotations, samples, documentation, customs clearance and shipping.

Long-Term Cooperation

We have served over 2,000 companies, including more than 50 customers who have worked with us for over 20 years.

OEM/ODM Support

We can support OEM/ODM customized development, new product trial production.

Whole-Process Order Follow-Up

Whole-process order follow-up: update production schedule & QC inspection photos regularly, guarantee on-time delivery and inform any unexpected issues timely. Products with quality issues can be returned and replaced as needed.

Custom Packaging

Large quantity orders can be customized with packaging and logos as per requirements.

Leading Custom Fastener Manufacturer In China

Shenzhen  Justwin Technology Co., Ltd. serves as the exclusive export division of Zhongshan Shenghong Machinery Technology Co., Ltd,which is established in 1993 and is a fastener company that integrates product research and development, sales and services.

Our integrated manufacturing base is equipped with complete production lines, a standardized quality control system and a professional technical team. We adopt unified standards in production management, quality inspection and R&D.

We specialize in the global supply of fasteners, hardware parts and customized mechanical components. Backed by integrated factory operations, we offer genuine factory-direct pricing, consistent and sufficient supply, as well as efficient, standardized one-stop export services.

We strive to deliver high-quality products and thoughtful international trade support for global clients, aiming to establish long-term, stable and win-win partnerships worldwide.

zhongshan longhong machinery factory building
Years of Experiences
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30+ Years of Fastener Manufacturing Experience

With more than 30 years of production and product development experience, we understand the requirements of standard fasteners, special fasteners and OEM projects.

100%

High Quality

98%

Technology

95%

Sustainability

fastener inspection report quality check
Need a Small Custom Order?

Our complete production lines allow us to arrange both small trial orders and large-volume production.

We support growing companies with flexible custom fastener development and negotiable MOQs based on the product and process.

fastener dimensional inspection technician
Worried About Product Quality?

We inspect each stage from incoming materials and production to surface treatment, packing and shipment.

Production and inspection are managed according to ISO 9001 procedures. Factory inspection reports can be provided, and third-party testing can be arranged when required.

pre shipment fastener packaging inspection
Worried About Delivery Delays?

Standard items in stock normally ship within 3–7 days. Rush orders can receive priority scheduling to help meet your shipment plan.

Custom fasteners and molded parts normally ship within 15–30 days, depending on product complexity.

OUR FACTORY

Fastener Manufacturing Facilities

Our 10,000+ m² self-owned factory is equipped with more than 80 production machines, supporting stable production for screws, rivets, pins and custom fasteners.

CUSTOM PRODUCTION PROCESS

From Your Drawing to Finished Fasteners

We manage each step from material inspection and tooling to batch production, testing, plating and final shipment.

01. Raw Material Inspection

Materials are checked before production to confirm type, dimensions and surface condition.

02. 3D Product Design

Our technical team reviews your drawing or sample and prepares the product design.

03. Mold Development

Custom molds and tooling are developed according to the confirmed structure and dimensions.

04. Sample Approval

Samples are produced for dimensional, assembly and performance confirmation.

05. Mass Production

Batch production begins after the sample and specifications are approved.

06. Electroplating

Surface treatments are selected according to corrosion resistance and appearance requirements.

07. Multiple Quality Inspections

Product dimensions, threads, appearance and key tolerances are checked during production.

08. Salt Spray Testing

Salt spray testing is arranged according to the required coating and corrosion resistance level.

09. Packing and Shipping

Products are packed with neutral or custom packaging and prepared for global shipment.
QUALITY & COMPLIANCE

Certificates and Test Reports for Buyer Review

Relevant quality and compliance documents can be provided based on the product, material, surface finish and destination market.

ISO 9001 Quality Management System

Supports standardized production management, quality inspection and process control.

EN 71-3 Material Safety Testing

Available for applicable fasteners and materials used in children-related products.

REACH Chemical Compliance

Testing documents can be provided for applicable materials and surface finishes.

RoHS Restricted Substance Compliance

Supports buyer reviews for products requiring controlled hazardous substance levels.
MEET US IN PERSON

Industry Exhibitions and Buyer Meetings

We attend industry exhibitions to present our products, meet global buyers and discuss drawings, samples and supply requirements face to face.

Client Testimonial

What that say about Justwintec

Hear what global buyers say about our product quality, delivery reliability and custom fastener support.

Other Questions

FAQs

Yes. We manufacture custom screws, rivets, bolts, nuts, pins and special fasteners based on your drawing or sample.

Small trial orders are available. MOQ depends on the material, size, process and tooling requirements.

Mold development normally takes 7–15 working days.

Minor mold adjustments for sample improvement can usually be made without an additional charge. Major structural changes will be quoted separately.

Common materials include:

  • Carbon steel
  • 40Cr alloy steel
  • Stainless steel SS304 and SS316
  • Stainless steel A2 and A4
  • Brass
  • Aluminum
  • Titanium

Other materials can be discussed according to your application.

Available surface treatments include:

  • Zinc plating
  • Black oxide
  • Dacromet
  • Nickel plating
  • Chrome plating
  • Zinc-nickel alloy coating

For zinc-plated products, salt spray resistance can be customized from approximately 48 to 500 hours depending on the coating system and project requirements.

Standard items in stock normally ship within 3–7 days.

Custom molded products normally require 15–30 days after sample confirmation.

Yes. We support OEM-branded packaging, custom logos and neutral export packaging.

Please provide:

  • Drawing or sample
  • Material
  • Surface treatment
  • Order quantity
  • Required tolerance
  • Target standard

The more complete the information, the faster we can provide an accurate quotation.

Yes. We can assist with export documentation, customs clearance and worldwide FCL or LCL shipment arrangements.

Send us a message

Feel Free to Reach Out for Further Details.

Looking for reliable fastener solutions? Justwintec is here to support your project with professional service, fast response, and stable factory supply.

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