QC/T 1179-2022Specifications for automobile wheel bolts (English PDF)

1 Scope

This document specifies the technical requirements and test methods for automobile wheel bolts (referred to as wheel bolts).

This document applies to automobile wheel bolts.

2 Normative references

The following documents are normatively referenced in this document and are indispensable for its application. For dated references, only the version corresponding to that date is applicable to this document; for undated references, the latest version (including all amendments) is applicable to this document.

GB/T 196, General purpose metric screw threads - Basic dimensions

GB/T 197, General purpose metric screw threads - Tolerances

GB/T 1958, Geometrical product specifications (GPS) - Geometrical tolerance - Verification

GB/T 3098.1-2010, Mechanical properties of fasteners - Bolts, screws and studs

GB/T 5779.1-2000, Fasteners - Surface discontinuities - Bolts, screws and studs for general requirements

GB/T 6478, Steels for cold heading and cold extruding

GB/T 13320, Metallographic grading atlas and assessing method for steel die forgings

GB/T 13682, Axial load fatigue testing for threaded fasteners

GB/T 30512, Requirements for prohibited substances on automobiles

JB/T 9151.1-1999, Method of verification for fasteners - Size and geometry - Bolts, screws, studs and nuts

QC/T 625, Metallic coatings and conversion coatings for automobiles

QC/T 715, Measuring method for friction coefficient of screw thread pair of automobiles

4 Technical requirements

4.6 The automobile manufacturer shall specify the stress level of the wheel bolts (average stress sigmam, stress amplitude sigmas, stress ratio r), and the number of cycles shall be 5 x 10^6. The wheel bolts shall not be cracked or broken.

4.7 During the vehicle reliability driving test, the wheel bolts shall not be cracked or broken.

4.8 During the vehicle durability driving test, the wheel bolts shall not be cracked or broken.

4.9 Surface discontinuities of wheel bolts shall comply with the provisions of GB/T 5779.1-2000.

4.10 The automobile manufacturer shall specify the surface treatment method for the wheel bolts. Among them, the wheel bolts of grade 8.8 can be surface-treated with galvanized passivation or non-electrolytic zinc plate coating or zinc-nickel alloys, and the wheel bolts of grade 10.9 can be surface-treated with non-electrolytic zinc plate coating or zinc-nickel alloys, as well as other surface treatments. Surface treatment shall comply with the regulations of QC/T 625. Prohibited substance content shall comply with the provisions of GB/T 30512.

4.11 The friction coefficient of the wheel bolts shall be agreed upon by the supplier and the buyer.

5 Test methods

5.1 The inspection of thread, size and geometric accuracy shall comply with the provisions of JB/T 9151.1-1999 and GB/T 1958.

5.2 The test methods for mechanical properties and physical properties shall be in accordance with the provisions of GB/T 3098.1-2010.

5.3 Carry out metallographic structure grading in accordance with the provisions of GB/T 13320.

5.4 The inspection of the grain flow line shall be in accordance with the regulations of ASTM E340.

5.5 Fatigue testing shall comply with the provisions of GB/T 13682.

5.6 The automobile manufacturer is responsible for the formulation and implementation of the vehicle reliability driving (loading) test program for wheel bolts.

5.7 The automobile manufacturer is responsible for the formulation and implementation of the automobile durability driving (mounting) test program for wheel bolts. […]