Inspection Standards For Truck U-Bolts Industry Trends And Best Practices

(MENAFN- GetNews) The inspection of truck U-bolts must cover dimensions, material properties, mechanical performance, and other aspects. The specific standards are as follows:

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1. Dimensional Accuracy Inspection ‌

Measurement Items‌: Length, width, thickness, thread accuracy, etc., using calipers, micrometers, or other precision tools to ensure compliance with design requirements.

Tolerance Requirements‌: When checking thread fit with go/no-go gauges, the“go” gauge should screw in smoothly, while the“no-go” gauge should not exceed 2 turns.

2. Surface Quality Inspection ‌

Visual Inspection‌: The surface must be smooth, free of rust, cracks, scratches, or other defects (checked by visual or tactile examination).

Coating Inspection‌: The galvanized coating should be uniform, with thickness meeting standards (e.g., salt spray test for corrosion resistance verification).

3. Material & Chemical Composition‌

Material Verification‌: Chemical composition analysis must confirm compliance with carbon steel (e.g., Q235) or stainless steel (e.g., 304) standards.

Grade Marking‌: Carbon steel bolts should have strength grade markings (e.g., 8.8), while stainless steel must indicate material codes.

4. Mechanical Performance Testing ‌

Tensile Strength‌: Verified via tensile testing, ensuring fractures occur in the threaded or non-threaded shank.

Hardness Testing‌: Measured using a hardness tester to ensure compliance with heat treatment requirements.

Torque & Preload Testing‌: Verify torque coefficient to ensure reliable installation.

5. Process & Defect Detection ‌

Cold Heading & Thread Rolling‌: Check for proper chamfering, burr-free edges, and no signs of mold damage.

Magnetic Particle Inspection (MPI)‌: Used to detect internal cracks, inclusions, or other hidden defects.

6. Standards & Certification ‌

Applicable Standards‌: Refer to QC/T 517-1999 (U-bolts for automobile leaf springs) or JB/ZQ 4321-97.

Packaging & Marking‌: Packaging must indicate national standards; bolt heads should be straight, and threads must be clean and free of contaminants.

Additional Notes‌:

For batch inspections, additional tests such as fatigue life and hydrogen embrittlement sensitivity may be required.

Inspection typically takes ‌3–5 working days‌, with complex cases extending to ‌7–10 days‌.

For U-bolts inquiries, please contact us via the details below

Manager:Helly Fu

E-mail: ...

Phone: +86 18750669913

Whatsapp: +86 18750669913

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