GB/T 3098.15-2023Mechanical properties of fasteners - Stainless steel nuts (English PDF)

Foreword

This document was drafted in accordance with the provisions of GB/T 1.1-2020

"Directives for standardization - Part 1.Rules for the structure and drafting of

standardizing documents".

This document is Part 15 of GB/T 3098 "Mechanical properties of fasteners". GB/T

3098 has published the following parts.

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

- GB/T 3098.2 Mechanical properties of fasteners - Nuts;

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

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

- GB/T 3098.6 Mechanical properties of corrosion-resistant stainless-steel fasteners

- Part 1.Bolts, screws and studs;

- GB/T 3098.7 Mechanical properties of fasteners - Thread rolling screws;

- GB/T 3098.8 Mechanical properties of fasteners - Parts for bolted connections for

use at temperatures from -200 °C ~ +700 °C;

- GB/T 3098.9 Mechanical properties of fasteners - Prevailing torque type steel nuts;

- GB/T 3098.10 Mechanical properties of fasteners - Bolts, screws, studs and nuts

made of non-ferrous metals;

- GB/T 3098.11 Mechanical properties of fasteners - Drilling screws with taping

screw thread;

- GB/T 3098.12 Mechanical properties of fasteners - Cone proof load test on nuts;

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

torques for bolts and screws with nominal diameters 1 mm to 10 mm;

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

- GB/T 3098.15 Mechanical properties of fasteners - Nuts made of stainless-steel;

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

steel;

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

of hydrogen embrittlement - Parallel bearing surface method;

- GB/T 3098.18 Mechanical properties of fasteners - Blind rivets testing;

- GB/T 3098.19 Mechanical properties of fasteners - Blind rivets with break pull

mandrel;

- GB/T 3098.20 Mechanical properties of fasteners - Wing nuts with specified proof

torque;

- GB/T 3098.21 Mechanical properties of fasteners - Part 21.Tapping screws of

stainless-steel;

- GB/T 3098.22 Mechanical properties of fasteners made of the fine grain non-heat

treatment steel - Bolts, screws and studs.

- GB/T 3098.23 Mechanical properties of fasteners - M42 ~ M72 bolts, screws and

studs;

- GB/T 3098.24 Mechanical properties of fasteners - Stainless steel and nickel alloys

bolts, screws, studs and nuts for high temperature applications;

- GB/T 3098.25 Mechanical properties of fasteners - Guidance for the selection of

stainless steels and nickel alloys for fasteners;

- GB/T 3098.26 Mechanical properties of fasteners - Flat washers.

This document replaces GB/T 3098.15-2014 "Mechanical properties of fasteners - Nuts

made of stainless-steel". Compared with GB/T 3098.15-2014, in addition to structural

adjustments and editorial changes, the main technical changes are as follows.

a) ADD the nut type information (see 5.1);

b) ADD the duplex (austenite-ferrite) stainless steel with performance levels of 70,

80, 100 (see Figure 1);

c) ADD the austenitic stainless steel performance level 100 and group A8 (see Figure

1);

d) ADD the design of stainless steel bolt and nut assemblies (see Chapter 6) and the

design principles of stainless steel nuts (see Appendix A);

e) CHANGE the surface finishing (see 7.3; 4.3 of the 2014 edition);

f) ADD the calculated value of the nut proof load and the principle of numerical

rounding (see Tables 5 ~ 8);

g) ADD the inspection procedure requirements and guidance (see Chapter 9);

h) ADD the thread size requirements for the mandrel of the nut proof load test (see

Appendix B);

i) CHANGE the proof load and hardness test methods (see Chapter 10; Chapter 7 of

the 2014 edition);

j) CHANGE the nut marking and labeling, adding the marking method for thin nuts

with reduced load capacity (see Chapter 11; 4.2 of the 2014 edition);

k) DELETE the common appendixes in the series of standards for mechanical

properties of stainless steel fasteners (see Appendix A ~ Appendix E of the 2014

edition).

This document modifies and adopts ISO 3506-2.2020 "Fasteners - Mechanical

properties of corrosion-resistant stainless steel fasteners - Part 2.Nuts of specified

groups and performance levels".

Compared with ISO 3506-2.2020, this document has made the following structural

adjustments.

- 10.2.2.1, 10.2.2.2, 10.2.2.3 correspond to 10.2.2 in ISO 3506-2.2020;

- ADD Figure 4; Figure 5 corresponds to Figure 4 in ISO 3506-2.2020, Figure 6

corresponds to Figure 5 in ISO 3506-2.2020, Figure 7 corresponds to Figure 6 in

ISO 3506-2.2020, Figure 8 corresponds to Figure 7 in ISO 3506-2.2020, Figure 9

corresponds to Figure 8 in ISO 3506-2.2020.

The technical differences between this document and ISO 3506-2.2020 and their

reasons are as follows.

- USE the normative reference GB/T 3098.25 to replace ISO 3506-6, to adapt to

China's technical conditions (see 7.1);

- USE the normative reference GB/T 39310 to replace ISO 16228, to adapt to China's

technical conditions (see 9.4);

- USE the normative reference GB/T 16825.1 to replace ISO 7500-1, to adapt to

China's technical conditions (see 10.1.3);

- USE the normative reference GB/T 228.1 to replace ISO 6892-1, to adapt to China's

technical conditions (see 10.1.5);

- USE the normative reference GB/T 3098.1 to replace ISO 898-1, to adapt to China's

technical conditions (see 10.1.6);

- USE the normative reference GB/T 4340.1 to replace ISO 6507-1, to adapt to

China's technical conditions (see 10.2.2.1);

- USE the normative reference GB/T 230.1 to replace ISO 6508-1, to adapt to China's

technical conditions (see 10.2.2.1);

- USE the normative reference GB/T 231.1 to replace ISO 6506-1, to adapt to China's

technical conditions (see 10.2.2.1);

- USE the normative reference GB/T 3099.4 to replace ISO 1891-4, to adapt to

China's technical conditions (see 11.4);

- DELETE the "soft" state of austenitic stainless steel performance grade 70 fasteners,

to meet the processing state of austenitic stainless steel fasteners (see Figure 1).

This document has made the following editorial changes.

- CHANGE the standard name to "Mechanical properties of fasteners - Stainless

steel nuts";

- USE the Chinese documents to replace the normative reference international

documents;

- CHANGE that "Stainless steel group marking (Part 1) consists of one letter..." to

"Stainless steel group marking (Part 1) consists of one letter and one digit..." (see

5.2.2);

- CHANGE the maximum and minimum values of the fixture apertures

corresponding to M5 and M6 after calculation according to tolerance grade D11

(see Table 9).

Please note that some contents of this document may involve patents. The issuing

agency of this document does not assume the responsibility for identifying patents.

This document was proposed by the China Machinery Industry Federation.

This document shall be under the jurisdiction of the National Technical Committee for

Standardization of Fasteners (SAC/TC 85).

Drafting organizations of this document. China Machinery Productivity Promotion

Center Co., Ltd., Shanghai Jiyoubiaowu High Strength Fastener Co., Ltd., Fu'an

Aozhan Industrial Co., Ltd., Hebei Wuwei Avionics Technology Co., Ltd., Wuxi

Standard Parts Factory Co., Ltd., and the Quality Supervision and Inspection Center for

General Parts of the Machinery Industry.

This document is interpreted by the National Technical Committee for Standardization

of Fasteners.

1 Scope

This document specifies the mechanical and physical properties of coarse and fine

thread nuts made of corrosion-resistant stainless steel, when tested at an ambient

temperature of 10 °C ~ 35 °C. The performance grades corresponding to the austenitic,

martensitic, ferritic and duplex (austenitic-ferritic) stainless steel nut groups are

specified.

2 Normative references

The contents of the following documents constitute the essential terms of this document

through normative references in the text. Among them, for dated references, only the

version corresponding to that date applies to this document; for undated references, the

latest version (including all amendments) applies to this document.

3 Terms and definitions

The following terms and definitions apply to this document.

4 Symbols

The following symbols apply to this document.

5 Marking system

The stainless steel group marking (Part 1) consists of a letter and a digit, wherein the

letter specifies the stainless steel category.

6 Design of bolt and nut connection pairs

The combination of performance grades of nuts and bolts, screws and studs shall be as

specified in Table 1.

7 Materials

Unless otherwise specified, nuts conforming to this document shall be cleaned and

polished.

To prevent corrosion, nuts should be used with bolts, screws, studs, washers of the same

stainless steel group (e.g., A2 nuts with A2 bolts). Other combinations may be used

(e.g., A4 nuts with D4 bolts), provided that.

8 Mechanical and physical properties

Whether during the manufacturing process or at the final product inspection, nuts of

specified stainless steel groups and performance grades shall meet the proof load and

hardness requirements specified in Tables 3 ~ 8, when tested at ambient temperatures

of 10 °C ~ 35 °C according to the methods specified in Chapter 10.

9 Inspection

The supplier may choose its own method (regularly evaluate the manufacturer, verify

the test results provided by the manufacturer, test the actual nuts, etc.), to control and/or

test the nuts provided by the manufacturer, to ensure that they meet the chemical

composition, mechanical and physical property requirements specified in Chapters 7

......