ASTM A1082 Specification

This specification covers high strength stainless steel bolting materials and bolting components for special purpose applications such as pressure vessels. Several grades of precipitation-hardened and duplex (ferritic-austenitic) stainless steels are covered. Selection will depend upon design, service conditions, mechanical properties and characteristics related to the application.

Chemical Composition

UNS DesignationB TypeB Carbon Manganese Phosphorus Sulfur Silicon Chromium Nickel Molybdenum Nitrogen Other Elements
Duplex (Ferritic-Austenitic) Grades
S31100 ... 0.06 1.00 0.045 0.030 1.00 25.0-27.0 6.0-7.0 ... ... Ti 0.25
S31260 ... 0.030 1.00 0.030 0.030 0.75 24.0-26.0 5.5-7.5 2.5-3.5 0.10-0.30 Cu 0.20-0.80,
W 0.10-0.50
S31803 ... 0.030 2.00 0.030 0.020 1.00 21.0-23.0 4.5-6.5 2.5-3.5 0.08-0.20 ...
S32101 ... 0.040 4.0-6.0 0.040 0.030 1.00 21.0-22.0 1.35-1.70 0.10-0.80 0.20-0.25 Cu 0.10-0.80
S32202 ... 0.030 2.00 0.040 0.010 1.00 21.5-24.0 1.0-2.80 0.45 0.18-0.26 ...
S32205 2205 0.030 2.00 0.030 0.020 1.00 22.0-23.0 4.5-6.5 3.0-3.5 0.14-0.20 ...
S32304 2304 0.030 2.50 0.040 0.030 1.00 21.5-24.5 3.0-5.5 0.05-0.60 0.05-0.20 Cu 0.05-0.60
S32506 -- 0.030 1.00 0.040 0.015 0.90 24.0-26.0 5.5-7.2 3.0-3.5 0.08-2.0 w 0.05-0.30
S32550 255 0.040 1.50 0.040 0.030 1.00 24.0-27.0 4.5-6.5 2.9-3.9 0.10-0.25 Cu 1.50-2.50
S32750 2507 0.030 1.20 0.035 0.020 0.80 24.0-26.0 6.0-8.0 3.0-5.0 0.24-0.32 Cu 0.50
S32760 -- 0.030 1.00 0.030 0.010 1.00 24.0-26.0 6.0-8.0 3.0-4.0 0.20-0.30 Cu 0.50-1.00,
W 0.50-1.00,
%Cr+3.3x%Mo
+16x%N≥40
S32906 ... 0.030 0.80-1.50 0.030 0.030 0.50 28.0-30.0 5.8-7.5 1.50-2.60 0.30-0.40 Cu 0.80
S32950 ... 0.030 2.00 0.035 0.010 0.60 26.0-29.0 3.5-5.2 1.00-2.50 0.15-0.35 ...
S39277 ... 0.025 0.80 0.025 0.002 0.80 24.0-26.0 6.5-8.0 3.0-4.0 0.23-.033 Cu 1.20-2.00,
W 0.80-1.20
Precipitation Hardening Grades
S15700 632 0.09 1.00 0.040 0.030 1.00 14.0-16.0 6.5-7.7 2.00-3.00 ... Al  0.75-1.50
S17400 630 0.07 1.00 0.040 0.030 1.00 15.0-17.0 3.0-5.0 ... ... Cu 3.0-5.0,
S17600 635 0.08 1.00 0.040 0.030 1.00 16.0-17.5 6.0·7.5 ... ... Cb +Ta 0.15·0.45
Al 0.40,
S17700 631 0.09 1.00 0.040 0.030 1.00 16.0·18.0 6.5·7.7 ... ... Ti 0.40·1.20
Al  0.75·1.50
S35500 634 0.10-0.15 0.50 1.25 0.040 0.030 0.50 15.0·16.0 4.0·5.0 2.5 3.2 0.07 0.13 Cb 0.10 0.50
Note:

A. Maximum or range unless otherwise indicated.
B. See Guide A959/A959M.

Mechanical Properties

Samples taken from product (see the section in Specification A962/A962M titled “Mechanical Properties”) shall conform to the mechanical properties of Tables 2-4.

Age hardened bolting material shall be capable of meeting the requirements prescribed in Table 3. Impact testing is required when S1 is invoked in the purchase order or contract.

Number of Tests:
Bolting Material— See 8.4 for hardness testing of bar. See the section in Specification A962/A962M titled “Number of Tests” for all other tests except those covered in 8.3.2.
Full Size Bolting Components— Headed bolts with a 1 1 ⁄ 2 in. [37 mm] body diameter and smaller, with a body length three times the diameter or longer and a required maximum tensile load of 160 000 lb/f [705 kN], produced by upsetting or forging (hot or cold) shall be subjected to full size testing. The testing shall be in addition to the tensile testing specified in above Bolting Point. The lot size shall be as shown in Specification A962/A962M (see the section titled Number of Tests). Failure shall occur in the body or threaded section with no failure, or indications of failure, such as cracks, at the junction of the head and shank. Wedge tensile testing is not required for flat countersunk head or socket button products.

Hardness Test:
Bolting Material Bars 2 in. [50 mm] and Over— One test on each mill-treated length.
Bolting Material Bars Under 2 in. [50 mm]— One test on at least 10 % of the mill treated lengths.

Mechanical Properties for PH Grades A

UNS Designation Type Solution TreatmentB,C °F [°C] Mechanical Property Requirements in the Solution Treated Condition
Tensile Strength ksi [MPa] Yield Strength ksi [MPa] Elongation in 2” [50 mm] or 4D, min. % Reduction of Area, min. % HardnessD
Rockwell, maximum Brinell, maximum
S15700 632 ... ... ... ... ... 100 HRB 269
S17400 630 Cool to below 90 [32] ... ... ... ... 38 HRC 363
S17600 635 Air Cool 120 [825] 75 [515] 10 45 32 HRC 302
S17700 631 ... ... ... ... ... 98 HRB 229
S35500 634 Hold at ≤ -100 [-73] for at least 3 hours ... ... ... ... ... 363
Note:

A. Values shown are minimums or ranges unless maximum is indicated.
B. 1900 [1040] ± 25°F [15°C].
C. Quenched in water unless the table specifies another media.
D. Either Rockwell or Brinell testing is permitted unless thickness is below 1⁄2 ” in which case Rockwell is preferred.

Age Hardening Heat Treatment and Mechanical Properties for PH Grades A

Type Condition Suggested Hardening and/or Aging Temperatures, Time at Temperature, and Quench Media °F [°C] B,C,D,E Maximum Thickness inch [mm] inclusive Mechanical Properties
Tensile Strength ksi [MPA] Yield Strength ksi [MPA] Elongation in 2” [50 mm] or 4D % Reduction of Area, % HardnessF Impact Ft-lbf [J]
Rockwell, HRC Brinell
630 H900 900 [480], 1 hour 8 190 [1310] 170 [1170] 10 35 40 388 ...
630 H925 925 [495], 4 hours 8 170 [1170] 155 [1070] 10 38 38 375 5 [6.8]
630 H1025 1025 [550], 4 hours 8 155 [1070] 145 [1000] 12 45 35 331 15 [20]
630 H1075 1075 [580], 4 hours 8 145 [1000] 125 [860] 13 45 32 311 20 [27]
630 H1100 1100 [595], 4 hours 8 140 [965] 115 [795] 14 45 31 302 25 [34]
630 H1150 1150 [620], 4 hours 8 135 [930] 105 [725] 16 50 28 277 30 [41]
630 H1150D 1150 [620] for 4 hrs., air cool plus
1150 [620] for 4 hrs., air cool 		8 125 [860] 105 [725] 16 50 24-33 255-311 30 [41]
630 H1150M 1400 [760] for 2 hrs., air cool plus
1150 [620] for 4 hrs., air cool 		8 115 [795] 75 [520] 18 55 24 255 55 [75]
631 RH950 1750 [955] for 10 min. to 1 h, rapidly cool to room temperature. Cool within 24 hrs. to -100 ± 10 [-75 ± 5], hold 8 hrs. min. Warm in air to room temperature. Heat to 950 [510] hold 1 h, air cool. 4 185 [1280] 150 [1030] 6 10 41 388 ...
631 TH1050 1400 [760] for 90 min. Cool to 55 ± 5 [15 ± 3] within 1 h, hold 1⁄2 h min., heat to 1050 [565], hold for 90 min., air cool 6 170 [1170] 140 [965] 6 25 38 352 ...
632 RH950 Same as Type 631 4 200 [1380] 175 [1210] 7 25 44 415 ...
632 TH1050 Same as Type 631 6 180 [1240] 160 [1100] 8 25 38 375 ...
634 H1000 1750 [955] for 10 min. to 1 h, water quench. Cool to -100 [75] min., hold 3 hrs. min. Temper at 1000 [540] hold for 3 h min, air cool. ... 170 [1170] 155 [1070] 12 25 37 341 ...
635 H950 950 [510], 1⁄2 h ... 190 [1310] 170 [1170] 8 25 39 363 ...
635 H1000 1000 [540], 1⁄2 h ... 180 [1240] 160 [1100] 8 30 37 352 ...
635 H1050 1050 [565], 1⁄2 h ... 170 [1170] 150 [1035] 10 40 35 331 ...
Note:

A. Values shown are minimums or ranges unless maximum is indicated.
B. ± 25°F [15°C].
C. Temperatures are suggested and may be varied to obtain the required tensile properties.
D. Time refers to the minimum time the material is at temperature and may be extended to obtain required ductility properties.
E. Quenching shall be accomplished using air or gas cooling unless the table specifies another media.
F. Either Rockwell or Brinell testing is permitted unless thickness is below 1⁄2 ” in which case Rockwell is preferred.

Heat Treatment and Mechanical Property Requirements for Duplex Grades A

UNS Designation Solution Temperature, °F [°C] B,C Size Range Mechanical Properties
Tensile Strength, ksi [MPA] Yield Strength, ksi [MPA] Elongation in 2” [50 mm] or 4D % HardnessD
Rockwell, HRC maximum Brinell, maximum
S31100 1900 [1040] -- 90 [620] 65 [450] 20 30 290
S31260 1870 to 2010
[1020 to 1100]		 -- 100 [690] 70 [485] 20 31 297
S31803 1900 [1040] -- 90 [620] 65 [450] 25 30 290
S32101 1870 [1020] -- 94 [650] 65 [450] 30 30 290
S32202 1800 to 1975
[980 to 1080]		 -- 94 [650] 65 [450] 30 30 290
S32205 1900 [1040] -- 95 [655] 65 [450] 25 30 290
S32304 1800 [980] -- 90 [620] 65 [450] 18 32 302
S32506 1870 - 2050 -- 90[620] 65 [450] 18 32 302
-- [1020 - 1120] --
S32550 1900 [1040] -- 110[760] 80 [550] 15 31 297
S32750 1880 - 2060
[1025 - 1125]		 2 in. and under 116[800] 80 [550] 15 33 310
>2 in. 110 [760] 75 [515] 15 33 310
S32760 2010 [1100] -- 109 (750] 80 [550] 25 30 290
S32900 1750 [955] -- 90 [620] 70 [485] 15 30 290
S32906 1830 to 2100 -- 109 [750] 80 [550] 25 33 310
[1000 to 1150]
Note:

A. Values shown are minimums or ranges unless maximum is indicated.
B. ± 25°F [15°C].
C. Quenched in water.
D. Either Rockwell or Brinell testing is permitted unless thickness is below 1⁄2 ” in which case Rockwell is preferred.

Nuts

Nuts made from the grades listed in this specification shall be furnished when specified in the purchase order. The mechanical test requirements of Section 8 apply in addition to requirements specified in the purchase order or contract. Hardness testing shall be done following the completion of all production heat treatment operations. See S5 for proof load testing and S6 for cross-sectional hardness testing.

Product Marking

UNS Designation Type Condition Grade Symbol
Duplex (Ferritic-Austenitic) Grade
S31100 -- -- 31100
S31260 -- -- 31260
S31803 -- -- 31803
S32101 -- -- 32101
S32202 -- -- 32202
S32205 2205 -- 32205
S32304 2304 -- 32304
S32506 -- -- 32506
S32550 255 -- 32550
S32750 2507 -- 32750
S32760 -- -- 32760
S32900 -- -- --
S32906 -- -- 32906
Precipitation Hardening Grades
S15700 632 -- 157
S15700 632 RH95 157A
S15700 632 TH1050 157B
S17400 630 -- 174
S17400 630 H900 174A
S17400 630 H925 174B
S17400 630 H1025 174C
S17400 630 H1075 174D
S17400 630 H1100 174E
S17400 630 H1150 174G
S17400 630 H1150D 174H
S17400 630 H1150M 174J
S17600 635 -- 176
S17600 635 H950 176A
S17600 635 H1000 176B
S17600 635 H1050 176C
S17700 631 -- 177
S17700 631 RH95 177A
S17700 631 TH1050 177B
S35500 634 -- 355
S35500 634 H1000 355A

Supplementary Requirements

S1. Charpy Impact Test

Charpy impact tests shall be run on samples representative of age hardened bolting material and shall meet the requirements of Table 3.

S2. Product Marking

Marking shall be applied to one end of studs and to the heads of bolts of all sizes. If the available area is inadequate the grade symbol may be marked on one end with the manufacturer’s identification symbol on the other end. For bolts smaller than 1 ⁄ 4 in. [6 mm] in diameter and studs smaller than 3 ⁄ 8 in. [10 mm] in diameter and for 1 ⁄ 4 in. [6 mm] in diameter studs requiring more than a total of three symbols, the marking shall be a matter of agreement between the purchaser and manufacturer.

S3. Stress Relieving

A stress-relieving operation shall follow straightening after heat treatment.

The stress-relieving temperature shall be 50 to 100°F [28 to 55°C] below the tempering temperature. Tests for mechanical properties shall be performed after stress-relieving.

S4. Non-Destructive Inspection

Each bar or forged blank of starting bolting material shall be subjected to NDE following final heat treatment. The method used shall be Eddy Current (EC), Magnetic Particle (MPI) (wet or dry), Liquid Penetrant (LPI), Ultrasonic (UT), or Visual Testing (VT), at the option of the producer. For LPI or MPI, linear indications (those indications longer than 1 ⁄ 16 in. [1.5 mm] with a length greater than three times their width) are unacceptable. For UT or ET, reject levels for linear indications shall be based on the alarm response from a surface notch with a maximum depth of 0.012 in. [0.30 mm] in a calibration bar. Product being subjected to VT shall be pickled prior to inspection. VT indications longer than 1 ⁄ 8 in. [3.2 mm] are prohibited.

Personnel performing the ultrasonic examinations shall be qualified and certified in accordance with a written procedure conforming to ASNT SNT-TC-1A (2006 or later) or another national standard that is acceptable to both the purchaser and the supplier.

S5. Proof Load Testing

Proof load testing of nuts is required. The number of tests and proof loads required shall be a matter of agreement between the purchaser and manufacturer.

S6. Cross-Sectional Hardness Testing on Nuts

Cross-sectional hardness testing of nuts is required in accordance with AnnexA3 of Test Methods A370. The number of tests required shall be a matter of agreement between the purchaser and manufacturer.

Referenced Document

ASTM Standards:
A276/A276M Specification for Stainless Steel Bars and Shapes.
A370 Test Methods and Definitions for Mechanical Testing of Steel Products.
A479/A479M Specification for Stainless Steel Bars and Shapes for Use in Boilers and Other Pressure Vessels.
A564/A564M Specification for Hot-Rolled and ColdFinished Age-Hardening Stainless Steel Bars and Shapes.
A959/A959M Guide for Specifying Harmonized Standard Grade Compositions for Wrought Stainless Steels.
A962/A962M Specification for Common Requirements for Bolting Intended for Use at Any Temperature from Cryogenic to the Creep Range.
ASNT Documents:
ASNT SNT-TC-1A Recommended Practice for Personnel Qualification and Certification in Nondestructive Testing.

Keywords

age-hardening stainless steel; bolts–stainless steel; duplex stainless steel; bolting components–stainless steel; high strength stainless steels; marking; nuts; precipitation hardening stainless steel; stainless steel bars; stainless steel bolting components