ASTM A193 TECHNICAL DATA

Order A193 B7 Stud Bolts Order A193 B8 Stud Bolts Order A193 B8M Stud Bolts Order A193 B16 Stud Bolts

ASTM A193 Grades and Markings

The ASTM A193 specification encompasses the standard that covers high-strength low-alloy steel shapes for bolting material used for pressure valves, flanges, vessels, and fittings for high-temperature applications.  For this specification, it covers wire, bars, bolts, studs, stud bolts, and screws. They are mainly used in chemical construction and petroleum applications. Although, this material is often utilized in national coarse thread pitches, but threads are specified 8 threads per inch (tpi) for diameters above 1 inch when being used in traditional applications.

Grades and Markings

ASTM A193 Mechanical Properties

ASTM A193 Specifications for Mechanical Properties governs the material specification defining mechanical properties, chemical composition, and preferential heat treatment. In addition, it governs product marking, hardness requirements, certifications, and more. ASTM A193 defines both SI (Metric) and inch-pound units.

Marking of Ferritic Steels
Grade Grade
B5B5
B6B6
B6XB6X
B7B7
B7MB7M or B7M
B16B16
B16+B16R

Marking of Austenitic Steels
Class GradeGrade Symbol
Class 1B8
B8C
B8M
B8P
B8T
B8LN
B8LMLN
B8CLN
B8ML4CuN
B8
B8C
B8M
B8P
B8T
B8F or B8LN
B8G or B8MLN
B8Y or B8CLN
B8YY or B8ML4CuN
Class 1AB8A
B8CA
B8MA
B8PA
B8TA
B8LNA
B8LMLNA
B8NA
B8MNA
B8MLCuNA
B8CLNA
B8ML4CuNA
B8A
B8B or B8CA
B8D or B8MA
B8D or B8MA
B8H or B8PA
B8J or B8TA
B8L or B8LNA
B8K or B8MLNA
B8V or B8MA
B8W or B8MNA
B9K or B8MLCuNA
B8Z or B8CLNA
B8ZZ or B8MLCuNA
Class 1BB8N
B8MN
B8MLCuN
B8N
B8Y or B8MN
B9J or B8MLCuN
Class 1CB8R
B8RA
B8S
B8SA
B9A or B8R
B9B or B8RA
B9D or B8S
B9F or B8SA
Class 1DB8
B8M
B8P
B8LN
B8MLN
B8N
B8MN
B8R
B8S
B8CLN
B8ML4CuN
B94
B95
B96
B97
B98
B99
B100
B101
B102
B103
B104
Class 2B8
B8C
B8P
B8T
B8N
B8M
B8MN
B8MLCuN
B8SH
B8CSH
B8PSH
B8TSH
B8NSH
B8MSH
B8YSH
B8JSH
Class 2BB8M2
B8
B9G or B8M2
B9
Class 2CB8M3 B9H or B8M3

MECHANICAL PROPERTIES

GradeDescription and UNS Diameter, in.Minimum Tempering Temperatur, FTensile Strength,
min,
ksi
Yield Strength,
min,
0.2 % offset,
ksi
Elongation in 4D,
min,
%
Reduction of Area,
min,
%
Hardness,
max
B5 4 to 6 % chromiumup to 4, incl1100100801650...
B6 13 % chromiumup to 4, incl1100100851550...
B6x 13 % chromiumup to 4, incl11009070165026 HRC
B7 Chromium-molybdenum2 1/2 and under
over 2 1/2 to 4
over 4 to 7
1100
1100
1100
125
115
100
105
95
75
16
16
18
50
50
50
321 HBW or 35 HRC
321 HBW or 35 HRC
221 HBW or 35 HRC
B7MA Chromium-molybdenum4 and under
over 4 to 7
1150
1150
100
100
80
75
18
18
50
50
235 HBW or 99 HRB
235 HBW or 99 HRB
B16 Chromium-molybdenum-vanadium2 1/2 and under
over 2 1/2 to 4
over 4 to 8
1200
1200
1200
125
110
100
105
95
85
18
17
16
50
45
45
321 HBW or 35 HRC
321 HBW or 35 HRC
321 HBW or 35 HRC
Grade, Diameter, in.Heat TreatmentBTensile Strength,
min,
ksi
Yield Strength,
min,
0.2 % offset, ksi
Elongation in 4D,
min,
%
Reduction of Area,
min,
%
Hardness, max
Classes 1 and 1D; B8, B8M, B8P, B8LN, B8MLN, B8CLN, all diametersCarbide solution treated75303050223 HBW or 96 HRBC
Classes 1 and 1 D: B8ML4CuN, diametersall carbide solution treated7025355090 HRB
Class 1 :B8C, B8T, all diameterscarbide solution treated75303050223 HBW or 96HRBC
Class 1A: B8A, B8CA, B8CLNA, B8MA, B8PA, B8TA, B8LNA, B8MLNA, B8NA, B8MNA,

B8MLCuNA, all diameters
carbide solution treated in the finished condition75303050192 HBW or 90HRB
Class 1A: B8ML4CuNA, all diameterscarbide solution treated7025355090 HRB
Classes 1B and 1D: B8N, B8MN, B8MLCuN, all diameterscarbide solution treated80353040223 HBW or 96 HRBC
Classes 1C and 1D: B8R, all diameterscarbide solution treated100553555271 HBW or 28 HRC
Class 1 C: B8RA, all diameterscarbide solution treated in the finished condition100553555271 HBW or 28 HRC
Classes 1C and 1D: B8S, all diameterscarbide solution treated in the finished condition95503555271 HBW or 28 HRC
Classes 1C: B8SA, all diameterscarbide solution treated in the finished condition95503555271 HBW or 28 HRC
Class 2: B8, B8C, B8P, B8T B8N,D3/4 and under

over 3/4 to 1, incl
over 1 to 1 1/4, incl
over 1 1/4 to 1 1/2, incl
carbide solution treated in the finished condition125

115
105
100
100

80
65
50
12

15
20
28
35

35
35
45
321 HBW or 35 HRC

321 HBW or 35 HRC
321 HBW or 35 HRC
321 HBW or 35 HRC
Class 2: B8M, B8MN, B8MLCuND3/4 and under

over 3/4 to 1, incl
over 1 to 1 1/4, incl
over 1 1/4 to 1 1/2, incl
carbide solution treated in the finished condition110

100
95
90
95

80
65
50
15

20
25
30
45

45
45
45
321 HBW or 35 HRC

321 HBW or 35 HRC
321 HBW or 35 HRC
321 HBW or 35 HRC
Class 2 B: B8, B8M2D 2 and under

over 2 to 2 1/2 incl
over 21/2 to 3 incl
carbide solution treated in the finished condition95

90
80
75

65
55
25

30
30
40

40
40
321 HBW or 35 HRC

321 HBW or 35 HRC
321 HBW or 35 HRC
Class 2C: B8M3D 2 and under

over 2
carbide solution treated in the finished condition85

85
65

60
30

30
60

60
321 HBW or 35 HRC

321 HBW or 35 HRC

A To meet the tensile requirements, the Brinell hardness shall be over 200 HBW (93 HRB).
B Class 1 is solution treated. Class 1A is solution treated in the finished condition for corrosion resistance; heat treatment is critical due to physical property requirement.
Class 2 is solution treated and strain hardened. Austenitic steels in the strain-hardened condition may not show uniform properties throughout the section particularly in sizes over 3⁄4 in. in diameter.
C For sizes 3⁄4 in. in diameter and smaller, a maximum hardness of 241 HBW (100 HRB) is permitted.
D For diameters 11⁄2 and over, center (core) properties may be lower than indicated by test reports which are based on values determined at 1⁄2 radius.

ASTM A193 Materials & Chemical Properties

Material and Chemical Property Requirements for the ASTM A193 governs minimum and maximum carbon, phosphorus, manganese, sulfur, silicon, chromium, nickel, and molybdenum percent content of steel fasteners within the ASTM A193 specification. The properties also include the minimum tempering temperature requirements. 

MATERIALS & CHEMICAL PROPERTIES

Ferritic Steels
Grade Description and UNS DesignationClassCarbonManganesePhosphorousSulfurSiliconChromiumNickelMolybdenumCooperColumbiumTitaniumVanadiumAluminumNitrogen
B55% Chromium 0.10 min1.000.0400.0301.004.0-6.0...0.40-0.65..................
Product Analysis VariationB0.010.030.0050.0050.050.10...0.05..................
B6, B6X12% Chromium (410),S41000 0.08-0.151.000.0400.0301.0011.5-13.5........................
Product Analysis VariationB0.01 over0.030.0050.0050.050.15........................
B7, B7MChromium- MolybdenumC 0.38-0.48D0.75-1
0.0350.0400.15-0.35
0.80-1.10...0.15-0.25...... .........
Product Analysis VariationB0.020.040.0500.0050.020.05...0.02..................
B16Chromium-Molybdenum-Vanadium 0.36-0.470.45-0.700.0350.0400.15-0.350.80-1.15...0.50-0.65.........0.25-0.350.015E...
Product Analysis VariationB0.020.030.0050.0050.020.05...0.03.........0.03......

 

Austenitic Steels
GradeDescription and UNS DesignationClassCarbonManganesePhosphorousSulfurSiliconChromiumNickelMolybdenumCooperColumbiumTitaniumVanadiumAluminumNitrogen
B8, B8A 304, S304001, 1A, 1D, 20.082.000.0450.0301.0018.0-20.0 8.0-11.0 .....................
Product Analysis VariationB0.010.040.0100.0050.050.20.15.....................
B8C, B8CA 347, S316001, 1A, 1D, 20.082.000.0450.0301.0017.0-19.0 9.0-12.0 ......10 x C to 1.10............
Product Analysis VariationB0.010.040.0100.0050.050.20.15......0.05 under... .........
B8M, B8MA, B8M2, B8M3316, S316001, 1A, 1D, 20.082.000.0450.0301.0016.0-18.0 10.0-14.0 2.00-3.00 ..................
Product Analysis VariationB0.010.040.0100.0050.20.150.1.....................
B8P, B8PA S305001, 1A, 1D, 20.122.000.0450.0301.0017.0-19.0 11.0-13.0 .....................
Product Analysis VariationB0.010.040.0100.0050.050.20.15.....................
B8N, B8NA 304N, S304511A, 1B, 1D, 20.082.000.0450.0301.0018.0-20.0 8.0-11.0 ...............0.10-0.16
Product Analysis VariationB0.010.040.0100.0050.050.20.15..................0.01
B8MN, B8MNA316N, S316511A, 1B, 1D, 20.082.000.0450.0301.0016.0-18.0 10.0-13.0 2.00-3.00 ...............0.10.-0.16
Product Analysis VariationB0.010.040.0100.0050.050.20.150.1...............0.01
M8MLCuN, B8MLCuNAS312541A, 1B, 1D, 20.021.000.0300.0100.8019.5-20.5 17.5-18.5 6.0-6.5 0.50-1.00 0.18-0.25
Product Analysis VariationB0.010.030.0050.0020.050.20.150.1...............0.02
B8T, B8TA 321, S321001, 1A, 20.082.000.0450.0301.0017.0-19.0 9.0-12.0 .........5 x(C + N) to 0.70......0.1
Product Analysis VariationB0.010.040.0100.0050.050.20.15 ......0.05 under .........
B8R, B8RA S209101C, 1D0.064.0-6.0 0.0450.0301.0020.5-23.5 11.5-13.5 1.50-3.00 ...0.10-0.30 ...0.10-0.30 ...0.20-0.40
Product Analysis VariationB0.010.050.0050.0050.050.250.150.1...0.05...0.02...0.02
B8S, B8SA S218001C, 1D0.107.0-9.0 0.0600.0303.5-4.5 16.0-18.0 8.0-9.0 ..................0.08-0.18
Product Analysis VariationB0.010.060.0050.0050.150.20.1..................0.1
B8LN, B8LNAS304531, 1A, 1D0.032.000.0450.0301.0018.0-20.0 8.00-11.0 ..................0.10-0.16
Product Analysis VariationB0.010.040.0100.0050.050.20.150.1...............0.01
B8CLN, B8CLNA347LN, 2347511, 1A, 1D0.005-0.0202.000.0450.0301.0017.0-19.0 9.0-13.0 ......0.020-0.050; 15 x carboncontent, min.........0.06-0.10
Product Analysis VariationB0.002 under, 0.01 over0.040.0100.0050.050.20.15......0.05.........0.01
B8ML4CuN, B8ML4CuNAS317301, 1A, 1Dover 0.03 2.000.0400.0101.0017.0-19.0 15.0-16.5 3.0-4.0 4.0-5.0 ............0.045
Product Analysis VariationB0.010.040.0050.0020.050.20.150.10.15............0.01

 

A Values are maximums unless a range or a minimum is indicated. Where ellipses appear in this table, there is no requirement and the element need not be determined or reported. The intentional addition of Bi, Se, Te, and Pb is not permitted.
B Product Analysis—Individual determinations sometimes vary from the specified limits as shown in the tables. The several determinations of any individual element in a heat may not vary both above and below the specified range. Product variation limits are over for maximums, over or under for ranges, and under for minimums, unless otherwise indicated.
C Typical steel compositions used for this grade include 4140, 4142, 4145, 4140H, 4142H, and 4145H. ^D For bar sizes over 31⁄2 in. [90 mm], inclusive, the carbon content may be 0.50 % max. For the B7M grade, a minimum carbon of 0.28 % is permitted, provided that the required tensile properties are met in the section sizes involved, the use of AISI 4130 or 4130H is allowed.
D For bar sizes over 31⁄2 in. [90 mm], inclusive, the carbon content may be 0.50 % max. For the B7M grade, a minimum carbon of 0.28 % is permitted, provided that the required tensile properties are met in the section sizes involved, the use of AISI 4130 or 4130H is allowed.
E Total of soluble and insoluble.