QC/T 1258-2025 Hose clamps with worm gear drive for Automobile, shape SmartSeal English, Anglais, Englisch, Inglés, えいご
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ICS
T
Professional Standard of the People's Republic of China
QC/T 1258-2025
Hose clamps with worm gear drive for Automobile, shape Smart Seal
汽车用蜗杆传动式软管夹箍 弹簧内衬补偿型
(English Translation)
Issue date: 2025-12-17 Implementation date: 2026-07-01
Issued by the Ministry of Industry and Information Technology of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative References
3 Terms and Definitions
4 Type Dimensions
5 Technical Requirements
6 Product NumberingHexagon Flange Bolts for Automotive Use
7 Product Numbering
8 Assembly Torque
9 Marking, Acceptance, and Packaging
Automotive Worm-Drive Hose Clamps with Spring-Liner Compensation Type
1 Scope
This document specifies the dimensional specifications, technical requirements, and acceptance packaging for automotive worm-drive hose clamps with spring-liner compensation type (hereinafter referred to as "clamps").
This document is applicable to hose clamps used for sealing connections between hoses and hard pipes in automotive systems such as cooling systems, air systems, and hydraulic systems.
2 Normative References
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 90.1 Acceptance inspection of fasteners
GB/T 90.2 Marking and packaging of fasteners
GB/T 1804 General tolerances — Tolerances for linear and angular dimensions without individual tolerance indications
GB/T 3280 Cold rolled stainless steel plates, sheets and strips
GB/T 4356 Stainless steel wire rods
GB/T 10125 Corrosion tests in artificial atmospheres — Salt spray tests
GB/T 30512 Requirements for prohibited substances in automobiles
QC/T 326 Product numbering rules for automotive standard parts
3 Terms and Definitions
No terms and definitions are specified in this document.
4 Symbols
The following symbols apply to this document.
D — Clamp supply diameter, in millimeters (mm).
Da — Clamp clamping diameter, in millimeters (mm).
Da m — Maximum clamp clamping diameter, in millimeters (mm).
Da min — Minimum clamp clamping diameter, in millimeters (mm).
D1 — Inspection mandrel diameter, in millimeters (mm).
5 Type and Dimensions
The type, dimensions, and specifications of the clamp are shown in Figure 1 and Table 1.
6 Technical Requirements
6.1 Material
The worm material shall be 06Cr19Ni10, according to GB/T 4356. The steel band, spring liner, and housing material shall be 06Cr19Ni10, according to GB/T 3280. Other materials with equivalent properties may be used, subject to agreement between the supplier and the purchaser.
6.2 Surface Treatment
The worm, steel band, spring liner, and housing shall have a polished surface finish. The complete clamp shall be subjected to a neutral salt spray test according to GB/T 10125 for 480 hours, and the area of red rust shall be less than 5%.
6.3 Prohibited Substances
Clamps requiring control of prohibited substances shall comply with the provisions of GB/T 30512.
6.4 Appearance Quality
The clamp surface shall be smooth, free from oil stains, and shall have no sharp edges, burrs, cracks, water rust, or other defects affecting its use.
6.5 Drive Thread
The drive thread shall be right-handed. The thread lead angle shall be less than 6°. Specific parameters shall be determined by the manufacturer.
6.6 Dimensional Inspection
The clamping range Da shall be inspected using the inspection mandrel shown in Figure 2. Other dimensions shall be inspected using general-purpose gauges.
6.8 Torque Performance
6.8.1 Test Conditions
Each test shall use a new clamp, which shall not be adjusted or relubricated.
The maximum error of the torque wrench shall be ±3%.
6.8.2 Free Torque
Within the clamping range, when turning the worm in any direction, the clamp torque shall be less than 0.8 Nm.
6.8.3 Proof Torque
The clamp shall be assembled on a steel mandrel. The mandrel diameter D1 shall be calculated according to Formula (1). The worm shall be turned until the torque reaches 10 Nm, and this torque shall be maintained for 2 minutes. After unloading, the clamp shall be visually inspected. No defects affecting performance are allowed, and the clamp shall be reusable.
6.8.4 Failure Torque
The clamp shall be assembled on a steel mandrel. The mandrel diameter D1 shall be calculated according to Formula (1). The worm shall be turned until failure. The failure torque shall be greater than 12 Nm.
6.9 Sealing Performance
The test method for sealing performance shall be determined by the supplier and purchaser based on the actual working conditions of the clamp. It shall ensure no leakage in the piping system.
7 Product Numbering
The product numbering of the clamp shall comply with the provisions of QC/T 326.
8 Assembly Torque
The user shall determine the assembly torque based on the sealing medium, hose material, and working conditions, ensuring no leakage or loosening in the piping system. The rotational speed of the assembly tool is recommended not to exceed 350 r/min. The assembly torque is recommended to be selected within the range of 5.5 to 9 Nm.
9 Marking, Acceptance, and Packaging
