GB/T 6078-2016Centre drills (English PDF)

Foreword

This standard was drafted in accordance with GB/T 1.1-2009 given rules.

This standard is GB/T 6078.1-1998 "Center drills Part 1. Centre without retaining cone drill -A type type and size", GB/T 6078.2-1998 "center drill Part 2. with care center cone -B type diamond type and size ", GB/T 6078.3-1998" center drill - part 3. arc-type center drill -R types and dimensions "and GB/T 6078.4-1998 "center drill Part 4. technology" combined with changes.

This standard replaces GB/T 6078.1-1998, GB/T 6078.2-1998, GB/T 6078.3-1998 and GB/T 6078.4-1998.

This standard and GB/T 6078.1-1998, GB/T 6078.2-1998, GB/T 6078.3-1998 and GB/T 6078.4-1998 compared to, the following technical differences.

4 section --- the original standards into a single standard;

--- Added "can also use high speed steel (Code HSS-E) to create" (see 5.3);

--- Remove the ISO foreword;

--- Appendix B to increase in the test parameters of high speed steel drill center.

This standard uses redrafted law revision of international standards ISO 866. 1975 "centers without retaining cone drill -A type", ISO 2540. 1973 "center with nursing cone drill -B type" and ISO 2541. 1972 "Arc -R-type center drill. " this standard and ISO 866. 1975, ISO 2540. 1973 and ISO 2541. 1972 compared to major differences are.

--- Marking an increase of 4, 5 Technical requirements 6 performance tests, marking and packaging 7, Annex A, Annex B.

The standard proposed by China Machinery Industry Federation.

This standard tool by the National Standardization Technical Committee (SAC/TC91) centralized.

This standard is mainly drafted by. Sichuan days tiger Tools Co., Ltd., Ningbo Chong Heng Tools Co., Ltd. Chengdu Tool Research Institute.

1 Scope

This standard specifies the basic requirements for the center drill type and size, technical requirements, labeling and packaging.

This standard applies to the processing GB/T 145 in A, B type, R-type center hole drilled in the center.

2 Normative references

The following documents for the application of this document is essential. For cited documents with dates, only the dated edition applies to this document. For undated references, the latest edition (including any amendments) applies to this document.

GB/T 145 center hole

3 Type and size

3.1 A-type center drill pattern in Figure 1, in line with the size dimension series in Table 1.

Figure 1 A-type center drill

Table 1 A-type center drill size in millimeters

Basic size limit deviation basic size limit deviation