QC/T 1263-2025 Automobile engines—Round wire retaining rings for piston pin bore English, Anglais, Englisch, Inglés, えいご
This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered.
ICS
T
Professional Standard of the People's Republic of China
QC/T 1263-2025
Automobile engines - Round wire retaining rings for piston pin bore
汽车发动机 活塞销孔用钢丝挡圈
(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 Types and Nomenclature of Parts
5 Technical Requirements
5.1 General Requirements
5.2 Material
5.3 Specification Identification
5.4 Surface Treatment
5.5 Surface Quality
5.6 Dimensions and Tolerances
5.7 Radial Clearance
5.8 Distortion
5.9 Elasticity
5.10 Assembly Performance
5.11 Cleanliness
6 Inspection Rules
7 Marking, Packaging, Transportation and Storage
Wire Snap Rings for Piston Pin Holes in Automotive Engines
1 Scope
This document specifies the terms and definitions, types and nomenclature of parts, technical requirements and test methods, inspection rules, marking, packaging, transportation, and storage for wire snap rings used in piston pin holes of automotive engines (hereinafter referred to as "snap rings").
This document applies to round wire snap rings for piston pin holes in automotive engines with nominal diameters ranging from 10 mm to 40 mm.
2 Normative References
The contents of the following documents become essential provisions of this document through normative reference herein. For dated references, only the edition corresponding to that date applies. For undated references, the latest edition (including all amendments) applies.
GB/T 2828.1 Sampling Procedures for Inspection by Attributes-Part 1: Sampling Schemes Indexed by Acceptance Quality Limit (AQL) for Lot-by-Lot Inspection
GB/T 4357-2022 Cold-Drawn Carbon Spring Steel Wires
GB/T 18983-2017 Quenched and Tempered Spring Steel Wires
JB/T 14615-2024 Internal Combustion Engines-Piston Assembly-Cleanliness Limits and Test Methods
3 Terms and Definitions
This document does not contain any terms or definitions that require definition.
4 Types and Nomenclature of Parts
The main types of wire snap rings for piston pin holes in automotive engines include Type A and Type C. The main type and dimensions of Type A snap rings are as shown in Figure 1, and the main type and dimensions of Type C snap rings are as shown in Figure 2. The main structure and dimensions of the snap ring groove in the piston pin hole are as shown in
Figure 3. Other snap rings with similar structures may refer to this standard for classification.
Index and Notation Description:
d₂ – Nominal diameter of the wire;
d₃ – Outer diameter of the snap ring in the free state;
h – Height of the Type A snap ring in the opening direction in the free state;
r – Inner diameter of the hook section of the Type A snap ring;
m₁ – Opening dimension when the snap ring is compressed to the nominal diameter d of the pin hole;
b – Length of the hook of the Type A snap ring.
Figure 1 Type A Snap Ring and Main Dimensions
5 Technical Requirements and Inspection Methods
5.1 General Requirements
Products shall be manufactured in accordance with product drawings and technical documentation approved through specified procedures.
5.2 Material
The material for snap rings should be Grade DH material specified in GB/T 4357-2022 or FDSiCr material specified in GB/T 18983-2017, or as agreed between the supplier and purchaser.
5.3 Specification Identification
Usually expressed as "Snap Ring Type – Nominal Diameter of Piston Pin Hole × Nominal Diameter of Wire Snap Ring".
Example: "C 18×1.3" indicates a Type C snap ring for a piston pin hole with a nominal diameter of 18 mm and a wire nominal diameter of 1.3 mm.
5.4 Surface Treatment
The surface of the snap ring is generally protected by applying rust-preventive oil. If the customer has special requirements, follow the customer's specifications.
5.5 Surface Quality
5.5.1 The surface of the snap ring shall be free from visible rust or cracks.
5.5.2 The protruding part formed by extrusion at the end of the snap ring during processing is called the extruded edge, and the maximum radial dimension t of the cross-sectional protruding part is the extruded edge size. The direction of extruded edge formation shall follow Figure 4 and Figure 5. For Type A snap rings, the extruded edge size at the cut of the hook section shall not exceed 0.3 × d₂. For Type C snap rings, the limit for extruded edge size t shall follow Table 1.
5.6 Dimensions and Tolerances
The main dimensions and tolerances of the snap rings shall follow Table 2.
5.7 Radial Clearance
Place the snap ring into a ring gauge with nominal diameter d and measure the radial clearance between them. The radial clearance shall meet the requirements in Table 3. During measurement, the part opposite the snap ring opening, the two opening ends, or the area near the hook radius shall be in contact with the ring gauge.
Table 3 Radial Clearance Requirements
5.8 Distortion
5.8.1 Measurement of distortion under no load shall follow Figure 6. The snap ring shall be able to pass through two vertically placed gap gauges spaced at c₁ under its own weight. c₁ shall follow Table 4.
QC/T 1263-2025 Automobile engines—Round wire retaining rings for piston pin bore English, Anglais, Englisch, Inglés, えいご
This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered.
ICS
T
Professional Standard of the People's Republic of China
QC/T 1263-2025
Automobile engines - Round wire retaining rings for piston pin bore
汽车发动机 活塞销孔用钢丝挡圈
(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 Types and Nomenclature of Parts
5 Technical Requirements
5.1 General Requirements
5.2 Material
5.3 Specification Identification
5.4 Surface Treatment
5.5 Surface Quality
5.6 Dimensions and Tolerances
5.7 Radial Clearance
5.8 Distortion
5.9 Elasticity
5.10 Assembly Performance
5.11 Cleanliness
6 Inspection Rules
7 Marking, Packaging, Transportation and Storage
Wire Snap Rings for Piston Pin Holes in Automotive Engines
1 Scope
This document specifies the terms and definitions, types and nomenclature of parts, technical requirements and test methods, inspection rules, marking, packaging, transportation, and storage for wire snap rings used in piston pin holes of automotive engines (hereinafter referred to as "snap rings").
This document applies to round wire snap rings for piston pin holes in automotive engines with nominal diameters ranging from 10 mm to 40 mm.
2 Normative References
The contents of the following documents become essential provisions of this document through normative reference herein. For dated references, only the edition corresponding to that date applies. For undated references, the latest edition (including all amendments) applies.
GB/T 2828.1 Sampling Procedures for Inspection by Attributes-Part 1: Sampling Schemes Indexed by Acceptance Quality Limit (AQL) for Lot-by-Lot Inspection
GB/T 4357-2022 Cold-Drawn Carbon Spring Steel Wires
GB/T 18983-2017 Quenched and Tempered Spring Steel Wires
JB/T 14615-2024 Internal Combustion Engines-Piston Assembly-Cleanliness Limits and Test Methods
3 Terms and Definitions
This document does not contain any terms or definitions that require definition.
4 Types and Nomenclature of Parts
The main types of wire snap rings for piston pin holes in automotive engines include Type A and Type C. The main type and dimensions of Type A snap rings are as shown in Figure 1, and the main type and dimensions of Type C snap rings are as shown in Figure 2. The main structure and dimensions of the snap ring groove in the piston pin hole are as shown in
Figure 3. Other snap rings with similar structures may refer to this standard for classification.
Index and Notation Description:
d₂ – Nominal diameter of the wire;
d₃ – Outer diameter of the snap ring in the free state;
h – Height of the Type A snap ring in the opening direction in the free state;
r – Inner diameter of the hook section of the Type A snap ring;
m₁ – Opening dimension when the snap ring is compressed to the nominal diameter d of the pin hole;
b – Length of the hook of the Type A snap ring.
Figure 1 Type A Snap Ring and Main Dimensions
5 Technical Requirements and Inspection Methods
5.1 General Requirements
Products shall be manufactured in accordance with product drawings and technical documentation approved through specified procedures.
5.2 Material
The material for snap rings should be Grade DH material specified in GB/T 4357-2022 or FDSiCr material specified in GB/T 18983-2017, or as agreed between the supplier and purchaser.
5.3 Specification Identification
Usually expressed as "Snap Ring Type – Nominal Diameter of Piston Pin Hole × Nominal Diameter of Wire Snap Ring".
Example: "C 18×1.3" indicates a Type C snap ring for a piston pin hole with a nominal diameter of 18 mm and a wire nominal diameter of 1.3 mm.
5.4 Surface Treatment
The surface of the snap ring is generally protected by applying rust-preventive oil. If the customer has special requirements, follow the customer's specifications.
5.5 Surface Quality
5.5.1 The surface of the snap ring shall be free from visible rust or cracks.
5.5.2 The protruding part formed by extrusion at the end of the snap ring during processing is called the extruded edge, and the maximum radial dimension t of the cross-sectional protruding part is the extruded edge size. The direction of extruded edge formation shall follow Figure 4 and Figure 5. For Type A snap rings, the extruded edge size at the cut of the hook section shall not exceed 0.3 × d₂. For Type C snap rings, the limit for extruded edge size t shall follow Table 1.
5.6 Dimensions and Tolerances
The main dimensions and tolerances of the snap rings shall follow Table 2.
5.7 Radial Clearance
Place the snap ring into a ring gauge with nominal diameter d and measure the radial clearance between them. The radial clearance shall meet the requirements in Table 3. During measurement, the part opposite the snap ring opening, the two opening ends, or the area near the hook radius shall be in contact with the ring gauge.
Table 3 Radial Clearance Requirements
5.8 Distortion
5.8.1 Measurement of distortion under no load shall follow Figure 6. The snap ring shall be able to pass through two vertically placed gap gauges spaced at c₁ under its own weight. c₁ shall follow Table 4.
