After the production of bolts, there should be a testing procedure. In the early stage, it is all sampling testing, and this important work is completed completely by manual work.

After the development of technology, related enterprises have introduced an advanced optical screening equipment to carry out the full automatic detection and selection of bolts.

Bolt inspection items:

Torque test, torque test, hardness test, slip resistance test, effective torque, locking performance, torque coefficient, fastening axial force, friction coefficient, slip resistance coefficient, screw in test, gasket spring, toughness,

Hydro-embrittlement test, flattening, flaring, reaming test, bending, (single-side, double-side) shear test, pendulum impact, stress relaxation, high-temperature creep,

stress endurance test, transverse vibration, fatigue test, metallographic analysis (microstructure analysis, microhardness test), chemical composition test, etc.

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After the production of bolts, there should be a testing process. In the early stage, it is sampling testing, which is completed by manual work.

After the development of technology, relevant enterprises have introduced an advanced optical screening equipment to carry out the full automatic detection and selection of bolts.

The bolt screening machine works by using CCD’s high-definition camera to convert the bolt to a visual image, and then the device’s software starts to work.

According to the height or color of the bolt and other information to determine its area, length and other dimensions, qualified bolts will enter the next step of automatic packaging, unqualified bolts will automatically flow into the waste bin.

Some domestic electronic equipment and auto parts, the number of bolts used in a large number.

If completely by manual selection, even the shipping speed can not meet the use of users, the use of optical screening machine can greatly improve the production efficiency and quality precision control.

Bolt testing standard:

GB/T Fastener bolts, screws and studs precoated with miniature adhesive coating – Technical requirements

GB/T Fastener bolts, screws and studs precoated polyamide locking layers – Technical requirements

GB/T 35853.3-2018 Aerospace equivalent glossary — Part 3: Bolts and nuts for aerospace

GB/T Fasteners – General specifications for bolts, screws, studs and nuts

Bolts or screws and conical elastic washer assemblies

Test method for extrusion strength of bolted connections of GB/T fiber reinforced plastic laminates

GJB general specification for bolts and screws with common thread.