GB/T 3098.7-2000Mechanical properties of fasteners. Thread rolling screws (English PDF)

Foreword

This Standard is identical to the international standard ISO 7085:1999

"Mechanical and performance requirements of case hardened and tempered

metric thread rolling screws".

The general title of GB/T 3098 is "Mechanical properties of fasteners", including

the following parts:

- GB/T 3098.1-2000 Mechanical properties of fasteners - Bolts, screws and

studs

- GB/T 3098.2-2000 Mechanical properties of fasteners - Nuts - Coarse

thread

- GB/T 3098.3-2000 Mechanical properties of fasteners - Set screws

- GB/T 3098.4-2000 Mechanical properties of fasteners - Nuts - Fine pitch

thread

- GB/T 3098.5-2000 Mechanical properties of fasteners - Tapping screws

- GB/T 3098.6-2000 Mechanical properties of fasteners - Stainless steel bolts,

screws and studs

- GB/T 3098.7-2000 Mechanical properties of fasteners - Thread rolling

screws

- GB/T 3098.8-1992 Mechanical properties of fasteners - Components for

bolted connections made mainly from materials with a high temperature

strength

- GB/T 3098.9-1993 Mechanical properties of fasteners - Prevailing torque

type steel hexagon nuts

- GB/T 3098.10-1993 Mechanical properties of fasteners - Bolts, screws,

studs and nuts made of non-ferrous metals

- GB/T 3098.11-1995 Mechanical properties of fasteners - Self-drilling

tapping screws

- GB/T 3098.12-1996 Mechanical properties of fasteners - Cone proof load

test on nuts

- GB/T 3098.13-1996 Mechanical properties of fasteners - Torsional test and

minimum torques for bolts and screws with nominal diameters from 1mm

to 10mm

- GB/T 3098.14-2000 Mechanical properties of fasteners - Widening test on

nuts

- GB/T 3098.15-2000 Mechanical properties of fasteners - Nuts made of

stainless-steel

- GB/T 3098.16-2000 Mechanical properties of fasteners - Set screws made

of stainless-steel

- GB/T 3098.17-2000 Mechanical properties of fasteners - Preloading test

for the detection of hydrogen embrittlement - Parallel bearing surface

method

ISO 7085 does not specify the content of footnote 1) (Clause 1).

This Standard is a revised edition of GB/T 3098.7-1986. The main changes are

as follows:

a) Modify the standard name;

b) Delete the mechanical property grades distinguished by materials and the

material designations for reference (Table 1);

c) ADD the provisions of "core hardness after retempering" (Table 2,

subclauses 4.9 and 5.8);

d) Delete the requirement of "anti-hydrogen embrittlement torque" and quote

the requirements of GB/T 3098.17 (Table 2, subclauses 4.8 and 5.7);

e) Adjust the provisions of "breaking torque" (Table 2, Table 3, subclauses

1 Scope

This Standard specifies the technical requirements for case hardened and

tempered thread rolling screws 1 ). Thread rolling screws according to this

Standard can produce various general female threads, in the range from 2 mm

~ 12 mm nominal thread diameter, for use in electromechanical products.

GB/T 3098.1 is not applicable to screws made according to this Standard.

2 Reference standards

The following standards contain provisions which, through reference in this

Standard, constitute provisions of this Standard. At the time of publication of

this Standard, the editions indicated are valid. All standards are subject to

revision. The parties who are using this Standard shall explore the possibility of

using the latest edition of the following standards.

GB/T 197-1981 General purpose screw threads - Tolerances and fits for

diameter from 1 to 355mm

GB/T 709-1988 Dimensions, shape, weight and tolerances for hot-rolled

plates and sheets

GB/T 3098.2-2000 Mechanical properties of fasteners - Nuts - Coarse thread

(idt ISO 898-2:1992)

GB/T 3098.17-2000 Mechanical properties of fasteners - Preloading test for

the detection of hydrogen embrittlement - Parallel bearing surface method

(idt ISO 15330:1999)

GB/T 4340.1-1999 Metallic materials - Vickers hardness test - Part 1: Test

method (eqv ISO 6507-1:1997)

GB/T 5267-1985 Electroplated coatings on threaded fasteners

1) It includes thread forming screws with a thread shank of arc-shaped triangular cross-

section in accordance with GB/T 6559.

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