GB/T 84-2018Square set screws with cup point (English PDF)

Foreword

This standard is one of the national standards for the "tightening screws" series. The series includes.

---GB/T 71 slotted tapered end set screws;

---GB/T 73 slotted flat end set screws;

---GB/T 74 slotted recessed set screws;

---GB/T 75 slotted long cylindrical end set screws;

---GB/T 77 hex flat end set screws;

---GB/T 78 hexagonal taper end set screws;

---GB/T 79 hexagonal cylindrical end set screws;

---GB/T 80 hex socket end set screws;

---GB/T 83 square head long cylindrical spherical end set screws;

---GB/T 84 square head concave end set screws;

---GB/T 85 square head long cylindrical end set screws;

---GB/T 86 square head short cylindrical cone end set screws;

---GB/T 821 square head flat end set screws.

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

This standard replaces GB/T 84-1988 "square head recessed set screws". Compared with GB/T 84-1988, the main technical changes are as follows.

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

---The mechanical performance grade of stainless steel was modified to. A1-12H, A2-12H, A2-21H and A4-21H (see Table 2);

--- Add non-ferrous metals CU2, CU3 (see Table 2);

--- For steel screws, remove surface oxidation treatment, increase the technical requirements of untreated and non-electrolytic zinc sheet coating according to GB/T 5267.2 (see Table 2);

--- For stainless steel screws, remove the untreated, add simple processing and passivation treatment technical requirements according to GB/T 5267.4 (see Table 2);

--- Add "If other technical requirements or surface treatment are required, the supply and demand agreement should be provided" (see Table 2);

--- Increase the surface defects of steel screws (see Table 2).

1 Scope

This standard specifies the type size, technical conditions and markings of the square head end set screws.

This standard is applicable to square head end set screws with thread specifications of M5~M20 and product grade A.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this document. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 90.1 fastener acceptance inspection

GB/T 90.2 Fastener Marking and Packaging

GB/T 193 Ordinary Thread Diameter and Pitch Series

GB/T 1237 fastener marking method

GB/T 2516 ordinary thread limit deviation

GB/T 3098.3 Fastener mechanical properties set screws

GB/T 3098.16 fastener mechanical properties stainless steel set screws

GB/T 3103.1 Fastener Tolerance Bolts, Screws, Studs and Nuts

GB/T 5267.1 fastener plating

GB/T 5267.2 fastener non-electrolytic zinc sheet coating

GB/T 5267.4 fastener surface treatment corrosion-resistant stainless steel passivation treatment

GB/T 5276 fastener bolts, screws, studs and nuts size code and label

GB/T 5779.1 fastener surface defects bolts, screws and studs are generally required

GB/T 9145 Ordinary thread medium precision, preferred series of extreme dimensions

GB/T 16938 fasteners, screws, studs and nuts - General technical requirements

3 Type size

The type and dimensions of the screws are shown in Figure 1 and Table 1. The size code and label should conform to GB/T 5276.