ASTM A193 Bolts

ASTM A193 specification covers alloy steel and stainless steel bolting material for pressure vessels, valves, flanges, and fittings for high temperature or high pressure service, or other special purpose applications. Ferritic steels are heat treated as best suits the high temperature characteristics of each grade. Immediately after rolling or forging, the bolting material shall be allowed to cool to a temperature below the cooling transformation range.

ASTM A193 Bolts, Screws, Studs, Stud Bolts, Threaded Rod Manufacturers and Suppliers

A193 Bolting Materials and bolting components supplied to this specification shall conform to the requirements of Specification A962/A962M. These requirements include test methods, finish, thread dimensions, macroetch (alloy steels only), marking, certification, optional supplementary requirements, and others. Failure to comply with the requirements of Specification A962/A962M constitutes nonconformance with this specification. In case of conflict between this specification and Specification A962/A962M, this specification shall prevail.ASTM A193 Bolts,screws,studs,andstud bolts shall be pointed and shall have a workmanlike finish. Points shall be flat and chamfered or rounded at option of the manufacturer. Length of point on studs and stud bolts shall be not less than one nor more than two complete threads as measured from the extreme end parallel to the axis. Length of studs and stud bolts shall be measured from first thread to first thread.

Most Common Grades of ASTM A193 Bolts

ASTM A193 Grade B5 Bolts – Quenched and tempered Stainless Steel 501

ASTM A193 Grade B6 Bolts – Martensitic Stainless Steel 410

ASTM A193 Grade B7 Bolts – Alloy Steel AISI 4140/4135/4142 Quenched and Tempered

ASTM A193 Grade B7M Bolts – ASTM A193 Grade B7M Bolts Alloy Steel AISI 4140/4135/4142 Quenched, Tempered & 100% Hardness Tested

ASTM A193 Grade B16 Bolts – Chromium- Molybdenum-Vanadium Alloy Steel Quenched and Tempered

ASTM A193 Grade B8 Bolts – Class1 Stainless Steel 304 Carbide solution Treated

ASTM A193 Grade B8M Bolts – Class1 Stainless Steel 316 Carbide solution Treated

ASTM A193 Grade B8M Bolts – Class 2 Stainless Steel 316 Carbide solution Treated and Strain Hardened

ASTM A193 Grade B8MLCuN Bolts – 254 Smo Stainless Steel Solution Annealed

Chemical Composition

ASTM A193 Chemical Composition

Type Ferritic Steels
Grade B5 B6 and B6X
UNS Designation 5% Chromium 12% Chromium
S 41000 (410)
Range Product Variation, Over or Under Range Product Variation, Over or Under
Carbon 0.1 min 0.01 under 0.15 max 0.01 over
Manganese, MAX 1.00 0.03 over 1.00 0.03 over
Phosphorus, MAX 0.040 0.005 over 0.040 0.005 over
Sulfur, MAX 0.030 0.005 over 0.030 0.005 over
Silicon 1.00 max 0.05 over 1.00 max 0.05 over
Chromium 4.0-6.0 0.10 11.5-13.5 0.15
Molybdenum 0.40-0.65 0.05

FERRITIC STEELS

Grade B7, B7M B16
Description Chromium-Molybdenum Chromium-Molybdenum-Vanadium
Range Product Variation, Over or Under Range Product Variation, Over or Under
Carbon 0.37-0.49 0.01 0.36-0.47 0.02
Manganese 0.65-1.10 0.04 0.45-0.70 0.03
Phosphorus, MAX 0.035 0.005 over 0.035 0.005 over
Sulfur, MAX 0.040 0.005 over 0.040 0.005 over
Silicon 0.15-0.35 0.02 0.15-0.35 0.02
Chromium 0.75-1.20 0.05 0.80-1.15 0.05
Molybdenum 0.15-0.25 0.02 0.50-0.65 0.03
Vanadium 0.25-0.35 0.03
Aluminum, MAX % 0.015

AUSTENITIC STEEL, CLASSES 1, 1A, 1D, AND 2

GradeB8, B8AB8C, B8CAB8M, B8MA, B8M2, B8M3B8P, B8PA

UNS Designation S 30400 (304) S 34700 (347) S 31600 (316) S 30500
Range Product Variation, Over or Under Range Product Variation, Over or Under Range Product Variation, Over or Under Range Product Variation, Over or Under
Carbon, MAX 0.08 0.01 over 0.08 0.01 over 0.08 0.01 over 0.12 0.01 over
Manganese, MAX 2.00 0.04 over 2.00 0.04 over 2.00 0.04 over 2.00 0.04 over
Phosphorus, MAX 0.045 0.010 over 0.045 0.010 over 0.045 0.010 over 0.045 0.010 over
Sulfur, MAX 0.030 0.005 over 0.030 0.005 over 0.030 0.005 over 0.030 0.005 over
Silicon MAX 1.00 0.05 over 1.00 0.05 over 1.00 0.05 over 1.00 0.05 over
Chromium 18.0-20.0 0.20 17.0-19.0 0.20 16.0-18.0 0.20 17.0-19.0 0.20
Nickel 8.0-11.0 0.15 9.0-12.0 0.15 10.0-14.0 0.15 11.0-13.0 0.15
Molybdenum 2.00-3.00 0.10
Columbium + Tantalum 10 x carbon content, min; 1.10 max 0.05 under

AUSTENITIC STEEL, CLASSES 1A, 1B, 1D, AND 2

GradeB8N, B8NAB8MN, B8MNAB8MLCuN, B8MLCuNA

UNS Designation S 30451 (304N) S 31651 (316N) S 31254
  Range Product Variation, Over or Under Range Product Variation, Over or Under Range
Carbon, MAX 0.08 0.01 over 0.08 0.01 over 0.020 0.01 over
Manganese, MAX 2.00 0.04 over 2.00 0.04 over 1.00 0.04 over
Phosphorus, MAX 0.045 0.010 over 0.045 0.010 over 0.030 0.010 over
Sulfur, MAX 0.030 0.005 over 0.030 0.005 over 0.010 0.005 over
Silicon, MAX 1.00 0.05 over 1.00 0.05 over 0.80 0.05 over
Chromium 18.0-20.0 0.20 16.0-18.0 0.20 19.5-20.5 0.20
Nickel 8.0-11.0 0.15 10.0-13.0 0.15 17.5-18.5 0.15
Molybdenum 2.00-3.00 0.10 6.0-6.5 0.10
Niltrogen 0.10-0.16 0.01 0.10-0.16 0.01 0.18-0.22
Copper 0.50-1.00

AUSTENITIC STEEL, CLASSES 1, 1A, AND 2

Grade B8T, B8TA
UNS Designation S 32100 (321)
Range Product Variation, Over or Under
Carbon, MAX 0.08 0.01 over
Manganese, MAX 2.00 0.04 over
Phosphorus, MAX 0.045 0.010 over
Sulfur, MAX 0.030 0.005 over
Silicon, MAX 1.00 0.05 over
Nickel 9.0-12.0 0.15
Chromium 17.0-19.0 0.20
Titanium 5 x (C + N) min, 0.70 max 0.05 under

Austenitic Steel, Classes 1C and 1D

Grade B8R, B8RA B8S, B8SA
UNS Designation S 20910 S 21800
Range Product Variation, Over or Under Range Product Variation, Over or Under
Carbon, max 0.06 0.01 over 0.10 0.01 over
Manganese 4.0-6.0 0.05 7.0-9.0 0.06
Phosphorus, max 0.045 0.005 over 0.060 0.005 over
Sulfur, max 0.030 0.005 over 0.030 0.005 over
Silicon 1.00 max 0.05 over 3.5-4.5 0.15
Chromium 20.5-23.5 0.25 16.0-18.0 0.20
Nickel 11.5-13.5 0.15 8.0-9.0 0.10
Molybdenum 1.50-3.00 0.10
Niltrogen 0.20-0.40 0.02 0.08-0.18 0.01
Columbium + Tantalum 0.10-0.30 0.05
Vanadium 0.10-0.30 0.02

Austenitic Steel, Classes 1, 1A and 1D

Grade B8LN, B8LNA B8MLN, B8MLNA
UNS Designation S 30453 S 31653
Range Product Variation, Over or Under Range Product Variation, Over or Under
Carbon, max 0.030 0.005 over 0.030 0.005 over
Manganese 2.00 0.04 over 2.00 0.04 over
Phosphorus, max 0.045 0.010 over 0.045 0.010 over
Sulfur, max 0.030 0.005 over 0.030 0.005 over
Silicon 1.00 0.05 over 1.00 0.05 over
Chromium 18.0-20.0 0.20 16.0-18.0 0.20
Nickel 8.0-11.0 0.15 10.0-13.0 0.15
Molybdenum 2.00-3.00 0.10
Niltrogen 0.10-0.16 0.01 0.10-0.16 0.01

Mechanical Properties

ASTM A193 Mechanical Properties

Ferritic Steels

Grade Diameter, in. Minimum Tempering Temperature, °F Tensile Strength, min, ksi Yield Strength, min, 0.2% offset, ksi Elongation in 4D, min, % Reduction of Area, min, % Hardness, max
B5, 4 to 6% chromium up to 4, incl 1100 100 80 16 50
B6, 13% chromium up to 4, incl 1100 110 85 15 50
B6X, 13% chromium up to 4, incl 1100 90 70 16 50 26 HRC
B7, Chromium-molybdenum 2 1/2 and under 1100 125 105 16 50 321 HB or 35HRC
over 2 1/2 to 4 11OO 115 95 16 50 321 HB or 35HRC
over 4 to 7 1100 100 75 18 50 321 HB or 35HRC
B7M, Chromium-molybdenum 4 and under 1150 100 80 18 50 235 HB or 99HRB
over 4 to 7 1150 100 75 18 50 235 HB or 99HRB
B16, Chromium-molybdenum-vanadium 2 1/2 and under 1200 125 105 18 50 321 HB or 35HRC
over 2 1/2 to 4 1200 110 95 17 45 321 HB or 35HRC
over 4 to 8 1200 100 85 16 45 321 HB or 35HRC

Austenitic Steels

Grade Diameter, in. Heat Treatment Tensile 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 all diameters carbide solution treated 75 30 30 50 223 HB or 96 HRB
Classes 1: B8C, B8T all diameters carbide solution treated 75 30 30 50 223 HB or 96 HRB
Classes 1A: B8A, B8CA, B8MA, B8PA, B8TA, B8LNA, B8MLNA, B8NA, B8MNA, B8MLCuNA all diameters carbide solution treated in the finished condition 75 30 30 50 192 HB or 90 HRB
Classes 1B and 1D: B8N, B8MN, and B8MLCuN all diameters carbide solution treated 80 35 30 40 223 HB or 96 HRB
Classes 1C and 1D: B8R all diameters carbide solution treated 100 55 35 55 271 HB or 28 HRC
Classes 1C: B8RA all diameters carbide solution treated in the finished condition 100 55 35 55 271 HB or 28 HRC
Classes 1C and 1D: B8S all diameters carbide solution treated 95 50 35 55 271 HB or 28 HRC
Classes 1C: B8SA all diameters carbide solution treated in the finished condition 95 50 35 55 271 HB or 28 HRC
Classes 2: B8, B8C, B8P, B8T, and B8N 3/4 and under carbide solution treated in the finished condition 125 100 12 35 321 HB or 35 HRC
over 3/4 to 1, incl 115 80 15 35 321 HB or 35 HRC
over 1 to 1 1/4, incl 105 65 20 35 321 HB or 35 HRC
over 1 1/4 to 1 1/2, incl 100 50 28 45 321 HB or 35 HRC
Classes 2: B8M, B8MN, B8MLCuN 3/4 and under carbide solution treated in the finished condition 110 95 15 45 321 HB or 35 HRC
over 3/4 to 1, incl 100 80 20 45 321 HB or 35 HRC
over 1 to 1 1/4, incl 95 65 25 45 321 HB or 35 HRC
over 1 1/4 to 1 1/2, incl 90 50 30 45 321 HB or 35 HRC
Class 2B: B8, B8M2 2 and under carbide solution treated in the finished condition 95 75 25 40 321 HB or 35 HRC
over 2 to 2 1/2 incl 90 65 30 40 321 HB or 35 HRC
over 2 1/2 to 3 incl 80 55 30 40 321 HB or 35 HRC
Class 2C: B8M3 2 and under carbide solution treated in the finished condition 85 65 30 60 321 HB or 35 HRC
over 2 85 60 30 60 321 HB or 35 HRC

Ferritic Steels

Class Diameter, (mm) Minimum Tempering Temperature, °C Tensile Strength, min, MPa Yield Strength, min, 0.2% offset, ksi Elongation in 4D, min, % Reduction of Area, min, % Hardness, max
B5, 4 to 6% chromium up to M100, incl 593 690 550 16 50
B6, 13% chromium up to M100, incl 593 760 585 15 50
B6X, 13% chromium up to M100, incl 593 620 485 16 50 26 HRC
B7, Chromium-molybdenum M64 and under 593 860 720 16 50 321 HB or 35HRC
over M64 to M100 593 795 655 16 50 321 HB or 35HRC
over M100 to M180 593 690 515 18 50 321 HB or 35HRC
B7M, Chromium-molybdenum M100 and under 620 690 550 18 50 235 HB or 99HRB
over M100 to M180 620 690 515 18 50 235 HB or 99HRB
B16, Chromium-molybdenum-vanadium M64 and under 650 860 725 18 50 321 HB or 35HRC
over M64 to M100 650 760 655 17 45 321 HB or 35HRC
over M100 to M180 650 690 588 16 45 321 HB or 35HRC

Austenitic Steels

Grade Diameter, (mm) Heat Treatment Tensile Strength, min, MPa Yield Strength, min, 0.2% offset, MPa Elongation in 4D, min, % Reduction of Area, min, % Hardness, max
Classes 1 and 1D: B8, B8M, B8P, B8LN, B8MLN all diameters carbide solution treated 515 205 30 50 223 HB or 96 HRB
Classes 1: B8C, B8T all diameters carbide solution treated 515 205 30 50 223 HB or 96 HRB
Classes 1A: B8A, B8CA, B8MA, B8PA, B8TA, B8LNA, B8MLNA, B8NA, B8MNA, B8MLCuNA all diameters carbide solution treated in the finished condition 515 205 30 50 192 HB or 90 HRB
Classes 1B and 1D: B8N, B8MN, and B8MLCuN all diameters carbide solution treated 550 240 30 40 223 HB or 96 HRB
Classes 1C and 1D: B8R all diameters carbide solution treated 690 360 35 55 271 HB or 28 HRC
Classes 1C: B8RA all diameters carbide solution treated in the finished condition 690 360 35 55 271 HB or 28 HRC
Classes 1C and 1D: B8S all diameters carbide solution treated 655 345 35 55 271 HB or 28 HRC
Classes 1C: B8SA all diameters carbide solution treated in the finished condition 655 345 35 55 271 HB or 28 HRC
Classes 2: B8, B8C, B8P, B8T, and B8N 3/4 and under carbide solution treated in the finished condition 860 690 12 35 321 HB or 35 HRC
over 3/4 to 1, incl 795 550 15 35 321 HB or 35 HRC
over 1 to 1 1/4, incl 725 450 20 35 321 HB or 35 HRC
over 1 1/4 to 1 1/2, incl 690 345 28 45 321 HB or 35 HRC
Classes 2: B8M, B8MN, B8MLCuN 3/4 and under carbide solution treated in the finished condition 760 665 15 45 321 HB or 35 HRC
over 3/4 to 1, incl 690 550 20 45 321 HB or 35 HRC
over 1 to 1 1/4, incl 655 450 25 45 321 HB or 35 HRC
over 1 1/4 to 1 1/2, incl 620 345 30 45 321 HB or 35 HRC
Class 2B: B8, B8M2 2 and under carbide solution treated in the finished condition 655 515 25 40 321 HB or 35 HRC
over 2 to 2 1/2 incl 620 450 30 40 321 HB or 35 HRC
over 2 1/2 to 3 incl 550 380 30 40 321 HB or 35 HRC
Class 2C: B8M3 2 and under carbide solution treated in the finished condition 585 450 30 60 321 HB or 35 HRC
over 2 585 415 30 60 321 HB or 35 HRC
Download PDF: ASTM A193 at ASTM.org

Related ASTM Specification

ASTM A320 / A320M – 15a : Standard Specification for Alloy-Steel and Stainless Steel Bolting for Low-Temperature Service

ASTM A194 / A194M – 16 : Standard Specification for Carbon Steel, Alloy Steel, and Stainless Steel Nuts for Bolts for High Pressure or High Temperature Service

ASTM F593 – 13a : Standard Specification for Stainless Steel Bolts, Hex Cap Screws, and Studs

ASTM F594 – 15 : Standard Specification for Stainless Steel Nuts

ASTM F2281 : Standard Specification for Stainless Steel and Nickel Alloy Bolts, Hex Cap Screws, and Studs, for Heat Resistance and High Temperature Applications Designation

Astm A193 Bolt Types

VIEW ALL PRODUCTS

Looking for Astm A193 Bolts

GET IN TOUCH
Rated 4 out of 5.0 for Astm A193 Bolts by 433+ OEMs and users on over 617+ projects.