GB/T 847-2017Cross-recessed raised countersunk (oval) head tapping screws (English PDF)

Foreword

This standard is "self-tapping screws" one of the national standards. This series includes.

--- GB/T 845 cross pan head self-tapping screws;

--- GB/T 846 countersunk countersunk head self-tapping screws;

--- GB/T 847 cross recessed countersunk head self-tapping screws;

--- GB/T 2670.1 hexagonal flower-shaped pan head tapping screws;

--- GB/T 2670.2 hexagonal flower-shaped countersunk head self-tapping screws;

--- GB/T 2670.3 hexagonal flower-shaped semi-countersunk head self-tapping screws;

--- GB/T 5282 slotted plate self-tapping screws;

--- GB/T 5283 Slotted countersunk head tapping screws;

--- GB/T 5284 Slotted semi-countersunk head self-tapping screws;

--- GB/T 5285 hex head self-tapping screws;

--- GB/T 9456 cross recessed hexagonal head self-tapping screws;

--- GB/T 13806.2 precision machinery fasteners cross-slotted tapping screw scraping end;

--- GB/T 16824.1 Hex flange self-tapping screws;

--- GB/T 16824.2 Hex flange self tapping screws.

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

This standard replaces GB/T 847-1985 "Cross recessed countersunk head self-tapping screws", compared with GB/T 847-1985, the main technical changes

as follows.

--- Increased R type (see Figure 1 and Table 1);

--- Increase the general technical conditions according to GB/T 16938 (see Chapter 2, Table 2);

--- Steel screws, non-treated zinc and non-electrolytic coating technology requirements according to GB/T 5267.2 (see Table 2);

--- Increase the stainless steel screw products and technical requirements (see Table 2);

--- Added "For other technical requirements or surface treatment, by the supply and demand agreement" (see Table 2).

This standard uses redrafted Law revision using ISO 7051.2011 "cross recessed half countersunk head self-tapping screws."

Technical differences from ISO 7051.2011 and their causes are as follows.

--- Normative references, with our standard instead of international standards (see Chapter 2), increase the reference GB/T 90.2 (see Table 2) and

GB/T 1237 (see 5.1), in line with China's basic standards fasteners;

--- Increase packaging technology requirements (see Table 2), in line with China's basic standards fasteners;

--- Modify the mark example To simplify the mark example (see 5.2), to comply with the provisions of GB/T 1237.

This standard is proposed by the China Machinery Industry Federation.

This standard by the National Standardization Technical Committee fasteners (SAC/TC85) centralized.

This standard is drafted by. Machine Productivity Promotion Center.

Participated in the drafting of this standard. Zhejiang Jingyi Standard Parts Co., Ltd..

This standard by the National Standardization Technical Committee fasteners responsible for the interpretation.

This standard replaces the standards previously issued as.

--- GB/T 847-1976, GB/T 847-1985.

Cross recessed countersunk head self tapping screws

1 Scope

This standard specifies the cross-groove semi-countersunk head tapping screws type size, technical conditions and marking.

This standard applies to thread specifications for the ST2.2 ~ ST9.5, product grade A cross recessed countersunk head self-tapping screws.

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated version applies to this article

Pieces. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 90.1 fastener inspection (GB/T 90.1-2002, idtISO 3269.2000)

GB/T 90.2 Fasteners signs and packaging

GB/T 944.1 screws with a cross slot (GB/T 944.1-1985, eqvISO 4757.1983)

GB/T 1237 fastener marking method (GB/T 1237-2000, eqvISO 8991.1986)

GB/T 3098.5 mechanical properties of fasteners Self-tapping screws (GB/T 3098.5-2016, ISO 2702.2011, MOD)

GB/T 3098.21 Mechanical properties of fasteners Stainless steel self-tapping screws (GB/T 3098.21-2014, ISO 3506-4.2008,

MOD)

GB/T 3103.1 Fasteners Tolerances Bolts, screws, studs and nuts (GB/T 3103.1-2002, idtISO 4759-1.2000)

GB/T 5267.1 fastener plating (GB/T 5267.1-2002, ISO 4042.1999, IDT)

GB/T 5267.2 fasteners non-electrolytic zinc coating (GB/T 5267.2-2002, ISO 10683.2000, IDT)

GB/T 5267.4 Fastener surface treatment corrosion-resistant stainless steel passivation treatment (GB/T 5267.4-2009, ISO 16048.2003,

IDT)

GB/T 5276 Fasteners - Bolts, screws, studs and nuts Dimensions Code and Notations (GB/T 5276-2015, ISO 225.

2010, MOD)

GB/T 5279 countersunk head screw head shape and measurement (GB/T 5279-1985, idtISO 7721.1983)

GB/T 5279.2 Countersunk head screw Part 2. Cross recessed depth (GB/T 5279.2-1997, idtISO 7721-2.1990)

GB/T 5280 self-tapping screws (GB/T 5280-2002, idtISO 1478.1999)

GB/T 16938 General requirements for fasteners bolts, screws, studs and nuts (GB/T 16938-2008, ISO 8992.

2005, IDT)

3 type size

Self-tapping screw type size shown in Figure 1 and Table 1.

Size code and label should be consistent with GB/T 5276.