GOST ISO 3506-2-2014 Mechanical properties of corrosion-resistant stainless steel fasteners. Part 2. Nuts
GOST ISO 3506-2 · Nuts
This is an informational translation of a Russian national standard. The Russian original is authoritative.
GOST ISO 3506-2-2014
Group G33
INTERSTATE STANDARD
MECHANICAL PROPERTIES OF CORROSION-RESISTANT STAINLESS STEEL FASTENERS
Part 2
Nuts
Mechanical properties of corrosion-resistant stainless steel fasteners. Part 2. Nuts
ICS 21.060.20
OKP 16 8000
Effective date 2017-01-01
Foreword
The objectives, basic principles and basic procedure for interstate standardization work are established by GOST 1.0-92 and GOST 1.2-2009.
Information about the standard
1 Prepared by FGUP “VNIINMASH” on the basis of its own authentic translation of the standard specified in item 5.
2 Submitted by Technical Committee for Standardization TC 229 “Fasteners”.
3 Adopted by the Interstate Council for Standardization, Metrology and Certification (minutes dated October 20, 2014, No. 71-P). The following voted for adoption:
| Short name of the country according to MC (ISO 3166) 004-97 | Country code according to MC (ISO 3166) 004-97 | Abbreviated name of the national standardization body |
|---|---|---|
| Azerbaijan | AZ | Azstandard |
| Armenia | AM | Ministry of Economy of the Republic of Armenia |
| Belarus | BY | Gosstandart of the Republic of Belarus |
| Georgia | GE | Gruzstandart |
| Kazakhstan | KZ | Gosstandart of the Republic of Kazakhstan |
| Kyrgyzstan | KG | Kyrgyzstandart |
| Moldova | MD | Moldova-Standard |
| Russia | RU | Rosstandart |
| Tajikistan | TJ | Tajikstandart |
| Turkmenistan | TM | Main State Service “Turkmenstandartlary” |
| Uzbekistan | UZ | Uzstandard |
| Ukraine | UA | Ministry of Economic Development of Ukraine |
4 By Order of the Federal Agency for Technical Regulation and Metrology dated June 10, 2015, No. 607-st, the standard was put into effect on January 1, 2017.
5 The standard is identical to ISO 3506-2:2009 “Mechanical properties of corrosion-resistant stainless steel fasteners - Part 2: Nuts”. Developed by subcommittee ISO/TC 2/SC 1 “Mechanical properties of fasteners” of technical committee ISO/TC 2 “Fasteners”. Translated from English.
The standard includes additional Annex DA “Chemical composition of corrosion-resistant steels”. Information on the compliance of interstate standards with reference international standards is given in Annex DB. The degree of compliance is identical (IDT).
6 Introduced for the first time.
1 Scope
The standard establishes the mechanical properties of nuts made from austenitic, martensitic and ferritic grades of corrosion-resistant stainless steel, when tested under ambient conditions from 10°C to 35°C. Mechanical properties change with increasing or decreasing temperature.
The standard applies to nuts:
- with nominal thread diameter D≤39 mm;
- with triangular metric thread, with diameter and pitch in accordance with ISO 68-1, ISO 261 and ISO 262;
- of any design;
- with widths across flats in accordance with ISO 272;
- with nominal height m≥0.5D.
The standard does not apply to nuts with special properties: locking capability, weldability.
Note - The designation system may be used for sizes beyond the limit given in this section (for example, D>39 mm), provided that all relevant mechanical and physical requirements for the property classes are met.
The standard does not establish requirements for corrosion resistance or oxidation resistance under special environmental conditions. Some information on materials for special conditions is given in Annex D. Definitions of corrosion and corrosion resistance are in accordance with ISO 8044.
The standard establishes the classification of corrosion-resistant stainless steel nuts by property class. Some of these steels may be used at low temperatures down to minus 200°C, others at high ambient temperatures up to 800°C. Information on the effect of temperature on mechanical properties is given in Annex E.
Corrosion resistance, oxidizability and mechanical properties at elevated and reduced temperatures may be agreed between the manufacturer and the customer in each specific case. The change in the risk of intergranular corrosion with increasing temperature depending on carbon content is shown in Annex F.
All fasteners made from austenitic stainless steels are non-magnetic under normal conditions; magnetic properties may appear after cold forming (see Annex G).
2 Normative references
The following referenced documents are required for the application of this standard. For dated references, only the cited edition applies.
ISO 68-1:1998 ISO general purpose screw threads. Basic profile. Part 1. Metric screw threads
ISO 261:1998 ISO general purpose metric screw threads. General plan
ISO 262:1998 ISO general purpose metric screw threads. Selected sizes for screws, bolts and nuts
ISO 272:1982 Fasteners. Hexagon products. Widths across flats
ISO 898-2:2012 Mechanical properties of fasteners made of carbon steel and alloy steel. Part 2. Nuts with specified property classes with coarse thread and fine pitch thread (supersedes ISO 898-6:1994)
ISO 3651-1:1998 Determination of resistance to intergranular corrosion of stainless steels. Part 1. Austenitic and ferritic-austenitic (duplex) stainless steels. Corrosion test in nitric acid medium by measurement of loss in mass (Huey test)
ISO 3651-2:1998 Determination of resistance to intergranular corrosion of stainless steels. Part 2. Ferritic, austenitic and ferritic-austenitic (duplex) stainless steels. Corrosion test in media containing sulfuric acid
ISO 6506-1:2005 Metallic materials. Brinell hardness test. Part 1. Test method
ISO 6507-1:2005 Metallic materials. Vickers hardness test. Part 1. Test method
ISO 6508-1:2005 Metallic materials. Rockwell hardness test. Part 1. Test method (scales A, B, C, D, E, F, G, H, K, N, T)
ISO 16048:2003 Passivation of corrosion-resistant stainless steel fasteners
ISO 16426:2002 Fasteners. Quality assurance system
3 Symbols
D - nominal thread diameter m - nut height (nominal value) P - thread pitch R - lower yield strength R₀,₂ - proof strength at 0.2% permanent elongation s - width across flats S - stress under proof load μ - magnetic permeability
4.1 Designations
The designation system for stainless steel grades and nut property classes is given in Figure 1. The material designation consists of two parts separated by a hyphen: steel grade and property class.
The designation of the steel grade (first part) consists of a letter:
- A - austenitic steel,
- C - martensitic steel, or
- F - ferritic steel,
and a number indicating the range of limit values of the chemical composition of this steel class (see Table 1).
The designation of the property class (second part) consists of two digits for nuts with height m≥0.8D (type 1, type 2 or hexagon flange nuts), representing 0.1 of the stress under proof load, and of three digits for nuts with height 0.5D≤m<0.8D (low nuts/type 0), where the first digit “0” indicates reduced load-bearing capacity, and the following digits represent 0.1 of the stress under proof load.
Example 1
A2-70 means: austenitic stainless steel, cold-formed, with stress under proof load (type 1 nuts) not less than 700 MPa (nut with m≥0.8D).
Example 2
C4-70 means: martensitic steel, quenched and tempered, with stress under proof load not less than 700 MPa (nut with m≥0.8D).
Example 3
A2-035 means: austenitic steel, cold-formed, with stress under proof load not less than 350 MPa (nuts with 0.5D≤m<0.8D).
Figure 1 - Designation system for stainless steel grades and nut property classes
The steel classes classified according to Figure 1 are described in Annex A and defined by chemical composition in Table 2.
Austenitic stainless steels with a carbon content not exceeding 0.03% may be additionally marked with the letter “L” (example - A4L-80).
Passivated nuts in accordance with ISO 16048 may be additionally marked with the letter “P” (example - A4-80P).
4.2 Marking
4.2.1 General
Nuts manufactured in accordance with the requirements of this standard shall be designated in accordance with the designation system described in 4.1, and marked in accordance with 4.2.2 and 4.2.3. The designation system and marking conditions shall be used only when all relevant requirements of the standard are met.
Note - For marking of left-hand threads, see ISO 898-2.
4.2.2 Manufacturer’s trademark
The manufacturer’s trademark shall be applied during the manufacturing process to all nuts marked with the property class symbol, provided this is technically feasible. It is recommended that nuts not marked with the property class symbol also be marked with the manufacturer’s trademark.
4.2.3 Nuts
All nuts with a nominal thread diameter D≥5 mm shall have clear marking in accordance with 4.1 and Figures 1-3. Marking is mandatory and shall include the steel grade and property class. Marking may be applied to only one side of the nut and only as an indentation if applied to the bearing surface of the nut. Alternatively, marking is permitted on the side face of the nut.
Figure 2 - Marking with material designation and manufacturer’s trademark
1 - manufacturer’s trademark; 2 - steel grade; 3 - property class
Figure 3 - Alternative marking in the form of grooves (only for steel grades A2 and A4)
s - width across flats
4.2.4 Packaging
All packaging for all types and sizes of nuts shall be marked (for example, by means of a tag/label). The marking shall include the manufacturer and/or seller identification, the marking symbol for the steel grade and property class, and the production batch number, as defined in ISO 16426.
4.3 Finish
Unless otherwise specified, nuts are supplied without additional treatment. Passivation is recommended to achieve maximum corrosion resistance. If passivation is required, it shall be carried out in accordance with ISO 16048. Nuts that have undergone passivation may be additionally marked with the symbol “P” after the steel grade and property class symbol.
For nuts manufactured to special order, identical marking shall be applied to the fastener and to the label. For nuts delivered from stock, additional marking shall be applied to the label.
5 Chemical composition
The chemical composition of stainless steels for nuts according to this standard is given in Table 1.
Note - The chemical composition given in Table 1 corresponds to the chemical composition in ISO 3506-1:2009, Table 1, for the respective steel grades.
The choice of chemical composition within the limits established for the steel grade is at the manufacturer’s discretion, otherwise subject to prior agreement between the manufacturer and the purchaser.
Where there is a risk of intergranular corrosion, testing in accordance with ISO 3651-1 or ISO 3651-2 is recommended. In such cases it is recommended to use stabilized stainless steels of grades A3 and A5, or grades A2 and A4 steels with a carbon content not exceeding 0.03%.
Table 1 - Stainless steel grades. Chemical composition
| Steel class | Steel grades | Chemical composition, mass fraction, % | Footnote | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| C | Si | Mn | P | S | Cr | Mo | Ni | Cu | |||
| Austenitic | A1 | 0.12 | 1 | 6.5 | 0.2 | 0.15-0.35 | 16-19 | 0.7 | 5-10 | 1.75-2.25 | |
| A2 | 0.10 | 1 | 2 | 0.05 | 0.03 | 15-20 | - | 8-19 | 4 | ||
| A3 | 0.08 | 1 | 2 | 0.045 | 0.03 | 17-19 | - | 9-12 | 1 | ||
| A4 | 0.08 | 1 | 2 | 0.045 | 0.03 | 16-18.5 | 2-3 | 10-15 | 4 | ||
| A5 | 0.08 | 1 | 2 | 0.045 | 0.03 | 16-18.5 | 2-3 | 10.5-14 | 1 | ||
| Martensitic | C1 | 0.09-0.15 | 1 | 1 | 0.05 | 0.03 | 11.5-14 | - | 1 | - | |
| C3 | 0.17-0.25 | 1 | 1 | 0.04 | 0.03 | 16-18 | - | 1.5-2.5 | - | - | |
| C4 | 0.08-0.15 | 1 | 1.5 | 0.06 | 0.15-0.35 | 12-14 | 0.6 | 1 | - | ||
| Ferritic | F1 | 0.12 | 1 | 1 | 0.04 | 0.03 | 15-18 | - | 1 | - | |
| Maximum values are given unless otherwise specified. Sulphur may be replaced by selenium. If the nickel content is less than 8%, the manganese content shall be at least 5%. If the nickel content exceeds 8%, the lower limit for copper content does not apply. Molybdenum may be present at the steel manufacturer’s discretion. If the molybdenum content affects the conditions of use of the steel, its content may be agreed between the steel manufacturer and the purchaser. If the chromium content is less than 17%, the nickel content shall be at least 12%. For austenitic steels with a minimum carbon content of 0.03%, the nitrogen content shall not exceed 0.22%. For stabilization, the titanium content shall be at least 5%C but not more than 0.8%, or the niobium (columbium) and/or tantalum content shall be at least 10%C but not more than 1.0%, marked accordingly as specified in this table. At the steel manufacturer’s discretion, the carbon content may be higher where necessary to achieve special mechanical properties, but shall not exceed 0.12%. Molybdenum may be present at the steel manufacturer’s discretion. Here a titanium content of at least 5%C but not more than 0.8% is permitted. Here a niobium and/or tantalum content of at least 10%C but not more than 1.0% is permitted. | |||||||||||
| Notes: 1 - A description of the specified stainless steel grades, taking into account their properties and fields of application, is given in Annex A. 2 - Examples of stainless steels standardized in accordance with ISO 683-13 and ISO 4954 are given in Annexes B and C respectively. 3 - Some materials for special applications are described in Annex D. |
6 Mechanical properties
The mechanical properties of nuts shall comply with those specified in Tables 2 and 3.
The following test methods shall be used to determine the mechanical properties specified in this section:
- hardness determination in accordance with 7.1 (only for steel grades C1, C3 and C4, hardened and tempered);
- proof load testing in accordance with 7.2.
Note - Despite the large number of property classes specified in this standard, not all classes are suitable for all nuts. Further guidance on the application of specific property classes is given in the relevant product standards.
For non-standard nuts, similar standard nuts shall be selected wherever possible.
Table 2 - Mechanical properties of nuts made of austenitic steel grades
| Steel class | Steel grade | Property class | Proof load stress, S, MPa, min | ||
|---|---|---|---|---|---|
| Nuts with m0.8D | Nuts with 0.5Dm<0.8D | Nuts with m0.8D | Nuts with 0.5Dm<0.8D | ||
| Austenitic | A1, A2 | 50 | 025 | 500 | 250 |
| A3, A4 | 70 | 035 | 700 | 350 | |
| A5 | 80 | 040 | 800 | 400 |
Table 3 - Mechanical properties of nuts made of martensitic and ferritic steel grades
| Steel class | Steel grade | Property class | Proof load stress, S, MPa, min | Hardness | ||||
|---|---|---|---|---|---|---|---|---|
| Nuts with m0.8D | Nuts with 0.5Dm<0.8D | Nuts with m0.8D | Nuts with 0.5Dm<0.8D | HB | HRC | HV | ||
| Martensitic | C1 | 50 | 025 | 500 | 250 | 147-209 | - | 155-220 |
| 70 | - | 700 | - | 209-314 | 20-34 | 220-330 | ||
| 110 | 055 | 1100 | 550 | - | 36-45 | 350-140 | ||
| C3 | 80 | 040 | 800 | 400 | 228-323 | 21-35 | 240-340 | |
| C4 | 50 | - | 500 | - | 147-209 | - | 155-220 | |
| 70 | 035 | 700 | 350 | 209-314 | 20-34 | 220-330 | ||
| Ferritic | F1 | 45 | 020 | 450 | 200 | 128-209 | - | 135-220 |
| 60 | 030 | 600 | 300 | 171-271 | - | 180-285 | ||
| Hardening and tempering at a minimum tempering temperature of 275°C. Nominal thread diameter D not exceeding 24 mm. |
7.1 Hardness test HB, HRC or HV
Hardness testing of nuts made of martensitic and ferritic steels shall be carried out in accordance with ISO 6506-1 (HB), ISO 6508-1 (HRC) or ISO 6507-1 (HV). In disputed cases, the Vickers hardness test (HV) is the deciding criterion for acceptance.
Test methods - in accordance with ISO 898-2.
Hardness values shall be within the limits specified in Table 3.
7.2 Proof load
The proof load test method for nuts and the acceptance criteria are in accordance with ISO 898-2.
Annex A (informative). Description of stainless steel classes and grades
A.1 General
All parts of ISO 3506 describe steel grades A1 to A5, C1 to C4 and F1, belonging to the following steel classes:
- austenitic steel, A1 to A5;
- martensitic steel, C1 to C4;
- ferritic steel, F1.
The annex also provides information on the non-standardized FA steel class, which has a ferritic-austenitic structure.
A.2 Class A steels (austenitic structure)
All parts of ISO 3506 describe five basic austenitic steel grades - A1 to A5. Steels of these grades cannot be hardened and are generally non-magnetic. Copper may be added to grades A1 to A5 to improve wear resistance (see Table 1).
For non-stabilized grades A2 and A4: a low carbon content is important, since the high affinity of chromium for carbon causes chromium carbide to form instead of chromium oxide, especially at elevated temperatures (see Annex F).
For stabilized grades A3 and A5: the elements Ti, Nb or Ta react with the carbon and allow the chromium oxide to exhibit its properties fully.
For offshore or similar applications, steels with a chromium and nickel content of approximately 20% and a molybdenum content of 4.5% to 6.5% are required. Where there is a high probability of corrosion, consultation with experts should be sought.
A.2.2 Grade A1 steels
Developed for mechanical engineering applications. Due to their high sulphur content, they are less corrosion-resistant than other grades in this group.
A.2.3 Grade A2 steels
The most commonly used stainless steels. Used for kitchen equipment and chemical industry apparatus. Not suitable for use with non-oxidizing acids or chlorine-containing compounds, for example in seawater or swimming pools.
A.2.4 Grade A3 steels
Stabilized stainless steels with properties similar to grade A2 steels.
A.2.5 Grade A4 steels
Acid-resistant, alloyed with molybdenum, more corrosion-resistant. Most widely used in the paper industry (developed for use with sulphuric acid), and to some extent suitable for chlorine-containing environments. Also commonly used in the food and shipbuilding industries.
A.2.6 Grade A5 steels
Stabilized, acid-resistant steels with properties similar to grade A4 steels.
A.3 Class F steels (ferritic structure)
All parts of ISO 3506 describe one ferritic steel grade - F1. Steels of this class generally cannot be hardened and should not be hardened in cases where it is possible. Grade F1 steels are magnetic.
A.3.2 Grade F1 steels
Usually used for simple equipment, with the exception of superferritic steels, which have a very low carbon and nitrogen content. Such steels can replace grades A2 and A3 and can be used in high-chlorine environments.
A.4 Class C steels (martensitic structure)
The standard includes three types of martensitic steel grades: C1, C3 and C4. Steels of this class can be hardened to very high strength and are magnetic.
A.4.2 Grade C1 steels
Limited corrosion resistance. Used in turbines, pumps and for knives.
A.4.3 Grade C3 steels
Limited corrosion resistance, better than grade C1 steels. Used in pumps and valves.
A.4.4 Grade C4 steels
Limited corrosion resistance. Used in mechanical engineering, otherwise similar to grade C1 steels.
A.5 Class FA steels (ferritic-austenitic structure)
Class FA steels are not described in all parts of ISO 3506, but will probably be described in a future version of the standard. They are known as duplex steels. The first FA steels developed had shortcomings that were addressed in steels developed later. Class FA steels are better than grades A4 and A5, particularly in terms of strength characteristics, and have increased resistance to pitting corrosion and stress corrosion cracking.
Table A.1 - Examples of the composition of steels with a ferritic-austenitic structure
| Steel class | Chemical composition, mass fraction, % | ||||||
|---|---|---|---|---|---|---|---|
| C, max | Si | Mn | Cr | Ni | Mo | N | |
| Ferritic-austenitic | 0.03 | 1.7 | 1.5 | 18.5 | 5 | 2.7 | 0.07 |
| 0.03 | <1 | <2 | 22 | 5.5 | 3 | 0.14 |
Annex B (informative). Chemical composition of stainless steels
(Excerpts from ISO 683-13:1986)
Table B.1 - Chemical composition of stainless steels
| Steel type | Chemical composition, mass fraction, % | Steel grade designation | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| C | Si | Mn | P | S | N | AI | Cr | Mo | Nb | Ni | Se, min | Ti | Cu | ||
| max | |||||||||||||||
| Ferritic steels | |||||||||||||||
| 8 | 0.08 | 1.0 | 1.0 | 0.040 | 0.030 | - | - | 16.0-18.0 | - | - | 1.0 | - | - | - | F1 |
| 8b | 0.07 | 1.0 | 1.0 | 0.040 | 0.030 | - | - | 16.0-18.0 | - | - | 1.0 | - | 7%C11.0 | - | F1 |
| 9c | 0.08 | 1.0 | 1.0 | 0.040 | 0.030 | - | - | 16.0-18.0 | 0.90-1.30 | - | 1.0 | - | - | - | F1 |
| F1 | 0.025 | 1.0 | 1.0 | 0.040 | 0.030 | 0.025 | - | 17.0-19.0 | 1.75-2.50 | - | 0.60 | - | - | - | F1 |
| Martensitic steels | |||||||||||||||
| 3 | 0.09-0.15 | 1.0 | 1.0 | 0.040 | 0.030 | - | - | 11.5-13.5 | - | - | 1.0 | - | - | - | C1 |
| 7 | 0.08-0.15 | 1.0 | 1.5 | 0.060 | 0.15-0.35 | - | - | 12.0-14.0 | 0.60 | - | 1.0 | - | - | - | C4 |
| 4 | 0.16-0.25 | 1.0 | 1.0 | 0.040 | 0.030 | - | - | 12.0-14.0 | - | - | 1.0 | - | - | - | C1 |
| 9a | 0.10-0.17 | 1.0 | 1.5 | 0.060 | 0.15-0.35 | - | - | 15.5-17.5 | 0.60 | - | 1.0 | - | - | - | C3 |
| 9b | 0.14-0.23 | 1.0 | 1.0 | 0.040 | 0.030 | - | - | 15.0-17.5 | - | - | 1.5-2.5 | - | - | - | C3 |
| 5 | 0.26-0.35 | 1.0 | 1.0 | 0.040 | 0.030 | - | - | 12.0-14.0 | - | - | 1.0 | - | - | - | C1 |
| Austenitic steels | |||||||||||||||
| 10 | 0.03 | 1.0 | 2.0 | 0.045 | 0.030 | - | - | 17.0-19.0 | - | - | 9.0-12.0 | - | - | - | A2 |
| 11 | 0.07 | 1.0 | 2.0 | 0.045 | 0.030 | - | - | 17.0-19.0 | - | - | 8.0-11.0 | - | - | - | A2 |
| 15 | 0.08 | 1.0 | 2.0 | 0.045 | 0.030 | - | - | 17.0-19.0 | - | - | 9.0-12.0 | - | 5%C0.80 | - | A3 |
| 16 | 0.08 | 1.0 | 2.0 | 0.045 | 0.030 | - | - | 17.0-19.0 | - | 10%C1.0 | 9.0-12.0 | - | - | - | A3 |
| 17 | 0.12 | 1.0 | 2.0 | 0.060 | 0.15-0.35 | - | - | 17.0-19.0 | - | - | 8.0-10.0 | - | - | - | A1 |
| 13 | 0.10 | 1.0 | 2.0 | 0.045 | 0.030 | - | - | 17.0-19.0 | - | - | 11.0-13.0 | - | - | - | A2 |
| 19 | 0.03 | 1.0 | 2.0 | 0.045 | 0.030 | - | - | 16.5-18.5 | 2.0-2.5 | - | 11.0-14.0 | - | - | - | A4 |
| 20 | 0.07 | 1.0 | 2.0 | 0.045 | 0.030 | - | - | 16.5-18.5 | 2.0-2.5 | - | 10.5-13.5 | - | - | - | A4 |
| 21 | 0.08 | 1.0 | 2.0 | 0.045 | 0.030 | - | - | 16.5-18.5 | 2.0-2.5 | - | 11.0-14.0 | - | 5%C0.80 | - | A5 |
| 23 | 0.08 | 1.0 | 2.0 | 0.045 | 0.030 | - | - | 16.5-18.5 | 2.0-2.5 | 10%C1.0 | 11.0-14.0 | - | - | - | A5 |
| 19a | 0.030 | 1.0 | 2.0 | 0.045 | 0.030 | - | - | 16.5-18.5 | 2.5-3.0 | - | 11.5-14.5 | - | - | - | A4 |
| 20a | 0.07 | 1.0 | 2.0 | 0.045 | 0.030 | 16.5-18.5 | 2.5-3.0 | - | 11.0-14.0 | - | - | - | A4 | ||
| 10N | 0.030 | 1.0 | 2.0 | 0.045 | 0.030 | 0.12-0.22 | - | 17.0-19.0 | - | - | 8.5-11.5 | - | - | - | A2 |
| 19N | 0.030 | 1.0 | 2.0 | 0.045 | 0.030 | 0.12-0.22 | - | 16.5-18.5 | 2.0-2.5 | - | 10.5-13.5 | - | - | - | A4 |
| 19AN | 0.030 | 1.0 | 2.0 | 0.045 | 0.030 | 0.12-0.22 | - | 16.5-18.5 | 2.5-3.0 | - | 11.5-14.5 | - | - | - | A4 |
| Type numbers are provisional and subject to change when the corresponding former standard is revised. Elements not listed must not be added to the steel without agreement between the steel manufacturer and the purchaser, except for elements intended to complete the melting process. All necessary precautions must be taken to prevent elements from scrap and materials used in production, which could affect the strength, mechanical properties and applicability of the steel, from entering the steel. Tantalum is reported as niobium. Not per ISO 683-13. Maximum mass fraction of (C+N) is 0.040%. Mass fraction 8(C+N) ≤ mass fraction (Nb+Ti) ≤ 0.80%. By agreement, when placing an order, the steel may be supplied with a Mo mass fraction between 0.20% and 0.60%. (C+N) not more than 0.040%. High resistance to intergranular corrosion. Stabilized steels. The manufacturer may add a Mo mass fraction of less than 0.70%. The maximum Ni mass fraction for cold working of blanks in seamless dies may be increased by 0.5%. |
Annex C (informative). Stainless steels for cold heading and cold forming
(Extracts from ISO 4954:1993)
Table C.1 — Stainless steels for cold heading and cold forming
| Steel type designation | Chemical composition, mass fraction, % | Steel grade designation | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Number | Designation | Per ISO 4954:1979 | C | Si | Mn | P | S | Cr | Mo | Ni | Other | |
| max | ||||||||||||
| Ferritic steels | ||||||||||||
| 71 | X 3 Cr 17 E | - | 0.04 | 1.00 | 1.00 | 0.040 | 0.030 | 16.0-18.0 | 1.0 | F1 | ||
| 72 | X 6 Cr 17 E | D1 | 0.08 | 1.00 | 1.00 | 0.040 | 0.030 | 16.0-18.0 | 1.0 | F1 | ||
| 73 | X 6 CrMo 17 1 E | D2 | 0.08 | 1.00 | 1.00 | 0.040 | 0.030 | 16.0-18.0 | 0.90-1.30 | 1.0 | F1 | |
| 74 | X 6 CrTi 12 E | - | 0.08 | 1.00 | 1.00 | 0.040 | 0.030 | 10.5-12.5 | 0.50 | Ti: 6%C1.0 | F1 | |
| 75 | X 6 CrNb 2 E | - | 0.08 | 1.00 | 1.00 | 0.040 | 0.030 | 10.5-12.5 | 0.50 | Nb: 6%C1.0 | F1 | |
| Martensitic steels | ||||||||||||
| 76 | X 12 Cr 13 E | D 10 | 0.09-0.15 | 1.00 | 1.00 | 0.040 | 0.030 | 11.5-13.5 | 1.0 | C1 | ||
| 77 | X 19 CrNi 16 2 E | D 12 | 0.14-0.23 | 1.00 | 1.00 | 0.040 | 0.030 | 15.0-17.5 | 1.5-2.5 | C3 | ||
| Austenitic steels | ||||||||||||
| 78 | X 2 CrNi 18 10 E | D 20 | 0.03 | 1.00 | 2.00 | 0.045 | 0.030 | 17.0-19.0 | 9.0-12.0 | A2 | ||
| 79 | X 5 CrNi 18 9 E | D 21 | 0.07 | 1.00 | 2.00 | 0.045 | 0.030 | 17.0-19.0 | 8.0-11.0 | A2 | ||
| 80 | X 10 CrNi 18 9 E | D 22 | 0.12 | 1.00 | 2.00 | 0.045 | 0.030 | 17.0-19.0 | 8.0-10.0 | A2 | ||
| 81 | X 5 CrNi 18 12 E | D 23 | 0.07 | 1.00 | 2.00 | 0.045 | 0.030 | 17.0-19.0 | 11.0-13.0 | A2 | ||
| 82 | X 6 CrNi 18 16 E | D 25 | 0.08 | 1.00 | 2.00 | 0.045 | 0.030 | 15.0-17.0 | 17.0-19.0 | A2 | ||
| 83 | X 6 CrNiTi 18 10 E | D 26 | 0.08 | 1.00 | 2.00 | 0.045 | 0.030 | 17.0-19.0 | 9.0-12.0 | Ti: 5%C0.80 | A3 | |
| 84 | X 5 CrNiMo 17 12 2 E | D 29 | 0.07 | 1.00 | 2.00 | 0.045 | 0.030 | 16.5-18.5 | 2.0-2.5 | 10.5-13.5 | A4 | |
| 85 | X 6 CrNiMoTi 17 12 2 E | D 30 | 0.08 | 1.00 | 2.00 | 0.045 | 0.030 | 16.5-18.5 | 2.0-2.5 | 11.0-14.0 | A5 | |
| 86 | X 2 CrNiMo 17 13 3 E | - | 0.03 | 1.00 | 2.00 | 0.045 | 0.030 | 16.5-18.5 | 2.5-3.0 | 11.5-14.5 | Ti: 5%C0.80 | A4 |
| 87 | X 2 CrNiMoN 17 13 3 E | - | 0.03 | 1.00 | 2.00 | 0.045 | 0.030 | 16.5-18.5 | 2.5-3.0 | 11.5-14.5 | N: 0.12-0.22 | A4 |
| 88 | X 3 CrNiCu 18 9 3 E | D 32 | 0.04 | 1.00 | 2.00 | 0.045 | 0.030 | 17.0-19.0 | 8.5-10.5 | Cu: 3.00-4.00 | A2 | |
| The first column gives sequential numbers. The second column gives designations according to the system proposed by International Technical Committee ISO/TC 17/SC 2. The third column gives obsolete numbers per ISO 4954:1979 (revised as ISO 4954:1993). Elements not listed in this table must not be added to the steel without agreement between the steel manufacturer and the purchaser, except for elements intended to complete the melting process. All necessary precautions must be taken to prevent elements from scrap and materials used in production, which could affect the strength, mechanical properties and applicability of the steel, from entering the steel. Not per ISO 4954. Very high resistance to intergranular corrosion. Stabilized steels. |
Annex D (informative). Austenitic stainless steels with special resistance to stress-corrosion cracking caused by chlorides
(Extracts from EN 10088-1:2005)
The risk of failure of bolts, screws and studs due to chloride-induced corrosion (for example, inside swimming pools) can be reduced by using the materials specified in Table D.1.
Table D.1 — Austenitic stainless steels with special resistance to stress-corrosion cracking caused by chlorides
| Austenitic stainless steels (designation/material number) | Chemical composition, mass fraction, % | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| C | Si | Mn | P | S | N | Cr | Mo | Ni | Cu | |
| max | ||||||||||
| X2CrNiMoN17-13-5 (1.4439) | 0.030 | 1.00 | 2.00 | 0.045 | 0.015 | 0.12- 0.22 | 16.5- 18.5 | 4.0- 5.0 | 12.5- 14.5 | |
| X1NiCrMoCu25-20-5 (1.4539) | 0.020 | 0.70 | 2.00 | 0.030 | 0.010 | 0.15 | 19.0- 21.0 | 4.0- 5.0 | 24.0- 26.0 | 1.20- 2.00 |
| X1NiCrMoCuN25-20-7 (1.4529) | 0.020 | 0.50 | 1.00 | 0.030 | 0.010 | 0.15- 0.25 | 19.0- 21.0 | 6.0- 7.0 | 24.0- 26.0 | 0.50- 1.50 |
| X2CrNiMoN22-5-3 (1.4462) | 0.030 | 1.00 | 2.00 | 0.035 | 0.015 | 0.10- 0.22 | 21.0- 23.0 | 2.5- 3.5 | 4.5- 6.5 | |
| Ferritic-austenitic stainless steel. |
Annex E (informative). Mechanical properties at elevated temperatures, use at low temperatures
Note — If bolts, screws and studs are correctly designed, the mating nuts automatically correspond to them. Therefore, for use at elevated or low temperatures it is sufficient to consider only the mechanical properties of the bolts, screws and studs.
E.1 Reduction in yield strength or proof strength at elevated temperatures
The values given in this annex are for information only. In practice, the chemical environment, the loading of the fasteners and the surrounding environment may differ significantly. In cases of fluctuating loads, prolonged exposure to elevated temperatures, or a high likelihood of stress corrosion, the purchaser should consult the manufacturer.
The values of yield strength R or proof strength R0.2 at elevated temperatures, expressed as a percentage of the values at room temperature, are given in Table E.1.
Table E.1 — Effect of temperature on R and R0.2
| Steel grade | R and R, %, at temperature | |||
|---|---|---|---|---|
| 100°C | 200°C | 300°C | 400°C | |
| A2, A3, A4, A5 | 85 | 80 | 75 | 70 |
| C1 | 95 | 90 | 80 | 65 |
| C3 | 90 | 85 | 80 | 60 |
| Note — The values apply only to property classes 70 and 80. |
E.2 Use at low temperatures
For the use of bolts, screws and studs made of stainless steel at low temperatures, see Table E.2.
Table E.2 — Use of bolts, screws and studs made of stainless steel at low temperatures (austenitic steels only)
| Steel grade | Lower limit of operating temperature for sustained exposure | |
|---|---|---|
| A2, A3 | -200°C | |
| A4, A5 | bolts and screws | -60°C |
| Studs | -200°C | |
| Due to the presence of the alloying element Mo, the stability of the austenite decreases and the transition temperature shifts toward higher values if the fasteners were subjected to a high degree of deformation during manufacture. |
Annex F (informative). Time-temperature diagram of intergranular corrosion in austenitic stainless steel grade A2 (18/8 steel)
Figure F.1 shows the approximate time for the risk of intergranular corrosion to appear for austenitic stainless steel grade A2 (18/8 steel) with various carbon contents, at temperatures from 550°C to 925°C.
Note — As the carbon content decreases, resistance to intergranular corrosion improves.
X — time, expressed in minutes; Y — temperature, expressed in degrees Celsius
Figure F.1 — Time-temperature diagram of intergranular corrosion in austenitic stainless steel grade A2
Annex G (informative). Magnetic properties of austenitic stainless steels
Where special magnetic properties are required, an experienced metallurgist should be consulted.
All fasteners made of austenitic stainless steels are non-magnetic under normal conditions, but some magnetic properties may appear after cold forming.
Every material is characterized by its ability to become magnetized, and this also applies to stainless steels. Only a vacuum can be completely non-magnetic. The magnetic permeability of a material is denoted by the coefficient μ, which represents the ratio of the material’s magnetic permeability to the magnetic permeability of a vacuum. A material has low magnetic permeability if its coefficient is close to 1.
Example 1: A2: μ=1.8.
Example 2: A4: μ=1.015.
Example 3: A4L: μ=1.005.
Example 4: F1: μ=5.
Annex DA (informative). Chemical composition of corrosion-resistant steels
(Extracts from GOST 5632-2014)
Table DA.1 — Chemical composition of corrosion-resistant steels
| Steel grade | Chemical composition, % | Designation of fastener grade | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Grade No. | Class name, steel grade | C | Si max | Mn max | P max | S max | Cr | Mo | Ni | Ti | |
| Ferritic steels | |||||||||||
| 3-7 | 12X17 | 0.12 max | 0.8 | 0.8 | 0.035 | 0.025 | 16-18 | - | - | - | F1 |
| 3-3 | 08X17T | 0.08 max | 0.8 | 0.8 | 0.035 | 0.025 | 16-18 | - | - | 5C - 0.8 | F1 |
| Martensitic steels | |||||||||||
| 2-3 | 12X13 | 0.09-0.15 | 0.8 | 0.8 | 0.030 | 0.025 | 12-14 | - | - | - | C1 |
| 1-12 | 20X17H2 | 0.17-0.25 | 0.8 | 0.8 | 0.035 | 0.025 | 16-18 | - | 1.5-2.5 | - | C3 |
| Austenitic steels | |||||||||||
| 6-4 | 03Kh17N14M3 | 0.03 max | 0.4 | 1-2 | 0.030 | 0.020 | 16.8-18.3 | 2.2-2.8 | 13.5-15 | - | A4 |
| 6-20 | 08X17H13M2T | 0.08 max | 0.8 | 2 | 0.035 | 0.020 | 16-18 | 2-3 | 12-14 | 5C - 0.7 | A5 |
| 6-35 | 10X17H13M2T | 0.10 max | 0.8 | 2.0 | 0.035 | 0.020 | 16-18 | 2-3 | 12-14 | 5C - 0.7 | A5 |
| 6-36 | 10Kh17N13M3T | 0.10 max | 0.8 | 2.0 | 0.035 | 0.020 | 16-18 | 3-4 | 12-14 | 5C - 0.7 | A5 |
| 6-40 | 12X18H9 | 0.12 max | 0.8 | 2.0 | 0.035 | 0.020 | 17-19 | - | 8-10 | - | A1 |
| 6-41 | 12X18H9T | 0.12 max | 0.8 | 2.0 | 0.035 | 0.020 | 17-19 | - | 8-10 | 5C - 0.8 | A3 |
| 6-11 | 04X18H10 | 0.04 max | 0.8 | 2.0 | 0.030 | 0.020 | 17-19 | - | 9-11 | - | A2 |
| 6-22 | 08X18H10 | 0.08 max | 0.8 | 2.0 | 0.035 | 0.020 | 17-19 | - | 9-11 | - | A2 |
| 6-23 | 08X18H10T | 0.08 max | 0.8 | 2.0 | 0.035 | 0.020 | 17-19 | - | 9-11 | 5C - 0.7 | A3 |
| 6-42 | 12X18H10T | 0.12 max | 0.8 | 2.0 | 0.035 | 0.020 | 17-19 | - | 9-11 | 5C - 0.8 | A3 |
| 6-6 | 03X18H11 | 0.03 max | 0.8 | 2.0 | 0.030 | 0.020 | 17-19 | - | 10.5-12.5 | - | A2 |
| 6-14 | 06X18H11 | 0.06 max | 0.8 | 2.0 | 0.035 | 0.020 | 17-19 | - | 10-12 | - | A2 |
| 6-7 | 03X18H12 | 0.03 max | 0.4 | 0.4 | 0.030 | 0.020 | 17-19 | - | 11.5-13.0 | 0.005 max | A2 |
| 6-24 | 08X18H12T | 0.08 max | 0.8 | 2.0 | 0.035 | 0.020 | 17-19 | - | 11-13 | 5C - 0.6 | A3 |
| Designation not per GOST 5632-2014. Not permitted for use in newly developed or upgraded equipment. |
Annex DB (informative). Information on the conformity of interstate standards to referenced international standards
Table DB.1 — Information on the conformity of interstate standards to referenced international standards
| Designation and title of the referenced international standard | Degree of conformity | Designation and title of the interstate standard |
|---|---|---|
| ISO 68-1:1998 ISO general purpose screw threads. Basic profile. Part 1. Metric screw threads | MOD | GOST 9150-2002 (ISO 68-1:1998)* Basic standards of interchangeability. Metric thread. Profile |
| ISO 261:1998 ISO general purpose metric screw threads. General plan | MOD | GOST 8724-2002 (ISO 261:1998)* Basic standards of interchangeability. Metric thread. Diameters and pitches |
| ISO 262:1998 ISO general purpose metric screw threads. Selected sizes for screws, bolts and nuts | - | ** |
| ISO 272:1982 Fasteners. Hexagon products. Widths across flats | NEQ | GOST 24671-84 Bolts, screws, and wood screws with hexagon head, and hexagon nuts. Width across flats |
| ISO 898-2:2012 Mechanical properties of fasteners made of carbon steel and alloy steel. Part 2: Nuts with specified property classes, coarse and fine pitch thread | IDT | GOST ISO 898-2… Mechanical properties of fasteners made of carbon steel and alloy steel. Part 2. Nuts with specified property classes, coarse and fine pitch thread |
| ISO 3651-1:1998 Determination of resistance to intergranular corrosion of stainless steels. Part 1. Austenitic and ferritic-austenitic (duplex) stainless steels. Corrosion test in nitric acid medium by measurement of loss in mass (Huey test) | MOD | GOST 6032-2003 (ISO 3651-1:1998, ISO 3651-2:1998)* Corrosion-resistant steels and alloys. Methods for testing resistance to intergranular corrosion. |
| ISO 3651-2:1998 Determination of resistance to intergranular corrosion of stainless steels. Part 2. Ferritic, austenitic and ferritic-austenitic (duplex) stainless steels. Corrosion test in media containing sulfuric acid | MOD | GOST 6032-2003 (ISO 3651-1:1998, ISO 3651-2:1998)* Corrosion-resistant steels and alloys. Methods for testing resistance to intergranular corrosion. |
| ISO 6506-1:2005 Metallic materials — Determination of Brinell hardness — Part 1: Test method | NEQ | GOST 9012-59 Metals. Method of Brinell hardness measurement |
| ISO 6507-1:2005 Metallic materials — Determination of Vickers hardness — Part 1: Test method | NEQ | GOST 2999-75 Metals and alloys. Method for measuring Vickers hardness |
| ISO 6508-1:2005 Metallic materials — Determination of Rockwell hardness — Part 1: Test method | NEQ | GOST 9013-59 Metals. Method of Rockwell hardness measurement |
| ISO 16048:2003 Passivation of corrosion-resistant stainless steel fasteners | IDT | GOST ISO 16048-2014 Passivation of fasteners made of corrosion-resistant stainless steel |
| ISO 16426:2002 Fasteners. Quality assurance system | IDT | GOST ISO 16426… Fasteners. Quality assurance system |
| * The technical deviations introduced ensure compliance with the requirements of this standard. ** There is no corresponding interstate standard. Until it is approved, it is recommended to use the Russian translation of this international standard. Note - The following symbols for the degree of conformity of standards are used in this table: - IDT - identical standards; - MOD - modified standards; - NEQ - non-equivalent standards. |
The standard is under development. GOST R ISO 898-2-2013 (ISO 898-2:2012, IDT) is in effect in Russia.
GOST R ISO 6507-1-2007 (ISO 6507-2:2005, IDT) is in effect in Russia.
The standard is under development. GOST R ISO 16426-2009 (ISO 16426:2002, IDT) is in effect in Russia.
Estimate for the “GOST ISO 3506-2” category
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