Quality Control

Haiyan Yihan Fasteners Factory

QC/Technical Support

Our in-house QC staff stringent quality inspection according to ISO 9001-compliant guidelines.

For the the special testing projects,we ask help from Testing Center in Shanghai Research Institute of Material, Shanghai Fasteners Testing Center and Zhejiang Standard Part Testing Center.

QC Staff



Directly sourcing from qualified raw material suppliers for our various processing workshops.

Procedures/testing Details

Our QC process (IQC→IPQC→OQC→FA) is carried out with professional inspection instruments.


We ask for testing report of every lot of raw material from material supplier.


We set up OMS (Optical Monitor System) for each equipments to improve qualification rate.
We set up screen grader for each equipments to separate scrap iron from product.
Our products continuously undergo strict inspections during production processes.


All quality control test results are linked to a computer system so that we can give our customers detailed reports on core hardness, surface hardness, drilling test, torque, bending, zinc-plating specifications and so on.


All of our managerial and technical staff study each reject carefully to avoid similar problems in the future.

Other Information

Our finely-tuned quality control process means
buyers can be fully confident in our ability to provide:

  • Guaranteed product quality
  • Excellent service
  • Reliability and stability