GB/T 10878-2026 Special taps of taper threads for gas cylinders 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
CCS
National Standard of the People's Republic of China
GB/T 10878-2026
Special taps of taper threads for gas cylinders
气瓶锥螺纹丝锥
Issue date: 2026-09-28 Implementation date: 2027-01-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Types and dimensions
5 Technical requirements
5.1 Materials and hardness
5.2 Appearance and surface roughness
5.3 Thread profile
5.4 Connection requirements
5.5 Thread base diameter
5.6 Square head dimensional tolerances
5.7 Positional tolerances
6 Performance tests
6.1 Test requirements and methods
6.2 Test conditions
6.3 Evaluation of test results
7 Marking and packaging
7.1 Marking
7.2 Packaging
Figure 1 — Types and dimensions of taper thread
Figure 2 — Thread profile and dimensions of taper thread
Table 1 — Taper thread dimensions
Table 2 — Thread profile dimensions of taper thread
Table 3 — Maximum allowable values of taper thread surface roughness
Table 4 — Circular runout tolerances of various parts of taper thread
Table 5 — Cutting specifications
Taper thread taps for gas cylinders
1 Scope
This document specifies the types and dimensions, technical requirements, performance tests, and marking and packaging of taper thread taps for gas cylinders.
This document is applicable to taps for machining internal taper threads conforming to GB/T 8335.
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 145, Centre holes
GB/T 8335, Special threads for gas cylinders
3 Terms and definitions
No terms and definitions are required to be defined in this document.
4 Types and dimensions
4.1 The types and dimensions of the taps are specified in Figure 1 and Table 1.
4.3 The centre holes at both ends of the tap shall be made in accordance with Type A of GB/T 145.
4.4 The bisector of the thread profile angle shall be perpendicular to the generatrix of the cone.
4.5 The pitch shall be measured parallel to the generatrix of the cone.
4.6 The nominal cutting angles of the tap are recommended as follows:
a) Rake angle not less than 8°;
b) Relief angle not less than 4°.
4.7 Marking examples are as follows:
A taper thread tap for gas cylinders with a basic thread size of 27.8 is marked as: PZ27.8 GB/T 10878—2026.
5 Technical requirements
5.1 Materials and hardness
5.1.1 Materials
The thread part of the tap shall be made of high-speed steel such as W6Mo5Cr4V2 or steel of equivalent or higher performance. The welded shank shall be made of 40Cr or steel of equivalent or higher performance.
5.1.2 Hardness
The hardness of the thread part of the tap shall not be less than 63 HRC, and the hardness of the square shank part shall not be less than 30 HRC.
5.2 Appearance and surface roughness
5.2.1 Appearance
The surface of the tap shall be free from defects such as cracks, chipping, burns and grinding burns that affect performance.
5.2.2 Surface roughness
The maximum allowable values of surface roughness of the tap shall comply with the provisions of Table 3.
Table 3 — Maximum allowable values of tap surface roughness
Standard
GB/T 10878-2026 Special taps of taper threads for gas cylinders (English)
GB/T 10878-2026 Special taps of taper threads for gas cylinders 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
CCS
National Standard of the People's Republic of China
GB/T 10878-2026
Special taps of taper threads for gas cylinders
气瓶锥螺纹丝锥
Issue date: 2026-09-28 Implementation date: 2027-01-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Types and dimensions
5 Technical requirements
5.1 Materials and hardness
5.2 Appearance and surface roughness
5.3 Thread profile
5.4 Connection requirements
5.5 Thread base diameter
5.6 Square head dimensional tolerances
5.7 Positional tolerances
6 Performance tests
6.1 Test requirements and methods
6.2 Test conditions
6.3 Evaluation of test results
7 Marking and packaging
7.1 Marking
7.2 Packaging
Figure 1 — Types and dimensions of taper thread
Figure 2 — Thread profile and dimensions of taper thread
Table 1 — Taper thread dimensions
Table 2 — Thread profile dimensions of taper thread
Table 3 — Maximum allowable values of taper thread surface roughness
Table 4 — Circular runout tolerances of various parts of taper thread
Table 5 — Cutting specifications
Taper thread taps for gas cylinders
1 Scope
This document specifies the types and dimensions, technical requirements, performance tests, and marking and packaging of taper thread taps for gas cylinders.
This document is applicable to taps for machining internal taper threads conforming to GB/T 8335.
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 145, Centre holes
GB/T 8335, Special threads for gas cylinders
3 Terms and definitions
No terms and definitions are required to be defined in this document.
4 Types and dimensions
4.1 The types and dimensions of the taps are specified in Figure 1 and Table 1.
4.3 The centre holes at both ends of the tap shall be made in accordance with Type A of GB/T 145.
4.4 The bisector of the thread profile angle shall be perpendicular to the generatrix of the cone.
4.5 The pitch shall be measured parallel to the generatrix of the cone.
4.6 The nominal cutting angles of the tap are recommended as follows:
a) Rake angle not less than 8°;
b) Relief angle not less than 4°.
4.7 Marking examples are as follows:
A taper thread tap for gas cylinders with a basic thread size of 27.8 is marked as: PZ27.8 GB/T 10878—2026.
5 Technical requirements
5.1 Materials and hardness
5.1.1 Materials
The thread part of the tap shall be made of high-speed steel such as W6Mo5Cr4V2 or steel of equivalent or higher performance. The welded shank shall be made of 40Cr or steel of equivalent or higher performance.
5.1.2 Hardness
The hardness of the thread part of the tap shall not be less than 63 HRC, and the hardness of the square shank part shall not be less than 30 HRC.
5.2 Appearance and surface roughness
5.2.1 Appearance
The surface of the tap shall be free from defects such as cracks, chipping, burns and grinding burns that affect performance.
5.2.2 Surface roughness
The maximum allowable values of surface roughness of the tap shall comply with the provisions of Table 3.
Table 3 — Maximum allowable values of tap surface roughness
