We dedicated over 12 years into the fasteners business, by decades of experiance, we are responsible to provide the most qualified fastener products for our valuable customers.

All the fasteners made by Jinyu Fastener, for those high tensile strength fasteners, especially over and including 8.8 grade or ASME GR5, will be sent to third lab for the physical properties inspection and issue the report.

We believe in our products can bring the reputation to our customer, and winning the market meanwhile.

For now, allow us to present the third party indepentent labs for your reference(

Zhejiang National Testing Technology Co.,Ltd

Shanghai Juncong Testing Technology Co.,Ltd

) which have been providing fastener inspection service with HB over years, they are all CNAS,CMA,ILAC-MRA,CAL certified and approved.



Zhejiang National Inspection and Testing Technology Co., Ltd. is the first national third-party testing organization to explore the reform and establishment of the national quality inspection system on the basis of the national standard parts product quality supervision and Testing Center (since 2001).

The company has passed CMA, CAL, CNAS, DILAC, NADCAP. Obtain the qualification of steel structure testing in construction industry. At present, the laboratory can carry out the testing of standard parts series products, metal materials, mechanical parts, welding materials, bearings, and other non-metallic materials such as composite materials, rubber, plastic, paint, etc.

At present, the laboratory covers an area of 10000 square meters, equipped with more than 350 sets of advanced equipment, such as American direct reading spectrometer, Zeiss microscope, scanning electron microscope, high temperature tensile testing machine, high temperature drying testing machine, high frequency and low frequency fatigue testing machine, phased array, TOFD and so on. The test results are accurate and reliable.


Safety Detection

Detection of harmful substances: analysis of harmful trace elements in product sample components, the analysis report
Testing equipment: direct reading spectrometer, inductively coupled plasma emission spectrometer
Hydrogen embrittlement performance: in the process of metal solidification, into which hydrogen can not be timely released, will spread to the nearby defects in metals, to room temperature atomic hydrogen defect in the synthesis and accumulation of molecular hydrogen, thus resulting in the great pressure, the metal crack; under stress, in solid solution hydrogen in metals may also cause hydrogen embrittlement, metal lattice in the wrong row atoms, hydrogen gathered near the dislocation, metal materials under the action of external force, the non-uniform stress distribution inside the material, the material shape rapidly transition region or the occurrence of stress concentration in the defects and micro cracks, due to hydrogen in the area of stress concentration and enrichment of the region to promote plastic deformation, resulting in the crack initiation and propagation; in the crystal has many micro cracks, crack aggregation hydrogen to adsorption on crack surface, the surface can be reduced, thus the crack propagation easier.
Detection equipment:
Fatigue reliability: fatigue test is a reliability test, the specimen or analog parts in various environments, subjected to alternating load and determination of its fatigue performance criteria, test and Study on the fracture process. The center can serve as a reliable performance of professional bodies can complete fatigue performance test of various products in accordance with the ISO, ASTM, DIN, GB, HB and other standards.
Testing equipment: fatigue test machine, constant temperature and humidity test machine, etc.
Defect detection: using machine vision detection technology of advanced detection of surface defects, defects on the surface of the spots, scratches, pits, chromatic aberration, defect detection.
Testing equipment: ultrasonic detector, cover thickness tester, magnetic powder flaw detection machine etc.

Chemical Analysis

Our laboratory can analyze the compositions of ferrous metal , non-ferrous metals and their alloys, Our laboratory also can test heavy metal, gas and elements according to ROHS.

Testing Items
Carbon analysis
Silicon analysis
Manganese analysis
Phosphorus analysis
Sulfur analysis
Chromium analysis
Nickel analysis
Molybdenum analysis
Vanadium analysis
Copper analysis
Titanium analysis
Cobalt analysis
Tungsten analysis
Aluminum analysis
Boron analysis
Niobium analysis
Salt spray test

Testing equipment
Optical Emission Spectroscopy Tester, ICP Spectroscopy Tester, Hydrogen Analyzer, Oxygen Nitrogen Analyzer, Carbon Sulfur Analyzer, Spectrophotometer.


Mechanical Performance Testing

Testing Items

Appearance dimensions :Screw gauge, roughness, all kinds of length dimensions

Short Term Mechanics: Brinell Hardness, Rockwell Hardness, Vickers Hardness, Re-tempering Test, Normal Temperature and High Temperature Tensile Test, Static Load Anchoring, Proof Load, all kinds of Prevailing Torques, Locking Performance, Torque Coefficient, Fastening Axial Force, Friction Coefficient, Anti Sliding Coefficient, Drive Test, Washer Spring, Toughness, Hydrogen Embrittlement Testing, Flattening, Rubber Bearing, Flaring, Widening Test on nuts, Bending, Single-sided and Double-sided shearing test, Pendulum Impact and etc.

Long Term Mechanics: Stress Relaxation, High Temperature Creep, Stress Rupture Test, Transverse Vibration, and Fatigue Test.

Testing Equipment: (small Exhibit attached)

Roughness Tester; Profilometer; Electro-hydraulic Servo Universal Testing machine (1---400T); Stress Relaxation Testing Machine; Static Load Anchoring Testing Machine; Microcomputer Servo Pressure Shearing Testing Machine; Torque Coefficient Tester; Vivtorinox Hardness Tester; Transverse Vibration Testing Machine, Fatigue Testing Machine, and Stress Rupture Testing Machine


Failure Analysis

Crack analysis

According to the common crack, crack, crack, crack, circumferential annular radial crack, arc crack, the observation and the analysis of the crack shape and grinding by high precision electronic microscope, find out the cause of the crack;

Fracture analysis

Fatigue source zone, analysis of fracture propagation region parts, transient fault zone, load type and size to find fault, find out the exact cause of fracture, in order to prevent the fracture failure again to take measures to provide the basis for;

Corrosion analysis

Mainly for their parts in the use process, due to corrosion, so as not to the design requirements of function, or corrosion fracture,or not the safe and reliable operation and service and failure, by looking for the cause of failure, to avoid repeated failure accidents like corrosion; eliminate hidden dangers, to overcome the weak link in production, improve the manufacturing quality of equipment, guarantee the safe operation and prolong the service life of the equipment; improved structure design of equipmentand improve the performance of the device, ensure the advanced equipment; to formulate operation process and operationreasonable rules of discovery and development of anti corrosion; the new theory, new materials and new technology for the production of services;

Analysis of unqualified process evaluation

The submission of the unqualified samples detection parameters, further analysis combined with the production process ofproducts, find the links exist production, processing products, and provide a reliable basis for the enterprises to improve product quality, material etc.;

Fracture analysis

Fracture always occurs in the metal microstructure of the weakest, recording a lot of valuable information about the whole process of fracture. And classification, the conclusion through the macroscopic morphology on the fracture surface andmicrostructure characteristics of the close relationship between the direct observation and analysis as well as with theenvironment and time factor.


Precision Measurement

The precision measurement businesses of our laboratory can measure the precise dimensions, shape and position tolerance, thread angle, major diameters、pitch diameters、minor diameters of the machinery parts, thread fasteners and special fastener products.

Testing Items
Dimensions Measure
From and Position Tolerance Measure
Thread Angle
Major Diameters、Pitch Diameters、Minor Diameters

Testing Equipment
MAHR profiler
Cylindricity Measuring Instrument
Thread precision measurement system


Metallographic Analysis

Metallographic Analysis Dept. mainly carries out the metallographic testing analysis of the fasteners and other metal products at present.

Testing Items:
Grain size
Non metallic inclusions
Intergranular corrosion
Micro hardness
Coating testing
Ferrite content testing
Magnetic testing

Testing Equipment
Hitachi scanning electron microscope (including energy spectrometer)
Zeiss microscope (Research Level)
High and low temperature environmental testing chamber
Stress corrosion testing machine
Program controlled heat treatment furnace


Meanwhile, HB is 7X24 standby for customer's testing requirement. Even for those which not made by HB, we are open to provide the third party test  service. Saving customers' value time, we can make it happen in China...