ASTM A193 Specification

ASTM A193 Specification

ASTM 193/A 193M is the standard that covers alloy and stainless steel bolting material for pressure vessels, valves, flanges, and fittings for high-temperature service.   The term bolting material as used in this specification covers bars, bolts, screws, studs, stud bolts, and wire. Bars and wire shall be hot-wrought. The material may be further processed by centerless grinding or by cold drawing. Austenitic stainless steel may be carbide solution treated or carbide solution treated and strain-hardened.  One of the most common alloy and stainless industrial fasteners is the Grade B7 studs and Grade B8 stud respectively.

Several grades are covered, including ferritic steels and austenitic stainless steels designated B5, B8, and so forth. Selection will depend upon design, service conditions, mechanical properties, and high-temperature characteristics.

The chemical composition of the ASTM grades are listed below.

ASTM A193 TENSILE STRENGTH / HARDNESS CHART

Grade and ClassDiameterTensile Strength Min KSIYield Strength 0.2% Offset KSIElongation in 4D, Min, %Reduction of Area Min, %Hardness Max BrinellHardness Max Rockwell
B5up to 4" incl100801650--
B6up to 4" incl110851550--
B6Xup to 4" incl90701650-C26
B7to 2-1/2"1251051650-C35
over 2-1/2 to 4"115951650-C35
over 4" to 7"100751850-C35
B7Mup to 4" incl100801850235B99
over 4" to 7"100751850235B99
B16to 2-1/2"1251051850321C35
over 2-1/2" to 4"110951745321C35
over 4" to 7"100851645321C35
Classes 1 and 1D: B8, B8M, B8P, B8LN, B8MLALL75303050223B96
Class 1: B8C, B8TALL75303050223B96
Class 1A: B8A, B8CA, B8MA, B8PA, B8TA, B8LNA, B8MLNA, B8NA, B8MNA, B8MLCuNAALL75303050192B90
Classes 1B & 1D: B8N, B8MN, B8MLCuNALL80353040223B96
Class 1C and 1D: B8RALL100553555271C28
Class 1C: B8RAALL100553555271C28
Classes 1C and 1D: B8SALL95503555271C28
Classes 1C: B8SAALL95503555271C28
Class 2: B8, B8C, B8P, B8T, B8Nto 3/4"1251001235321C35
over 3/4" to 1"115801535321C35
over 1" to 1-1/4"105652045321C35
over 1-1/4 to 1-1/2" incl100502845321C35
Class 2 B8M, B8MN, B8MLCuNto 3/4"110961545321C35
over 3/4" to 1"100802045321C35
over 1" to 1-1/4"95652545321C35
over 1-1/4 to 1-1/2" incl90503045321C35
Class 2B: B8, B8M2to 2" incl95752540321C35
over 2" to 2-1/2" incl90653040321C35
over 2-1/2 " to 3" incl80553040321C35
Class 2C: B8M3to 2" incl85653060321C35
over2"85603060321C35

ASTM A193 Chemical Requirements

ASTM A193 B5, B6, B6X - Ferritic Steels

Type

Ferritic Steels   

Identification

B5

B6 and B6X - S41000

Grade

5% Chromium (Type 501)12% Chromium (Type 410)

Element

Range

Tolerance +/-

Range

Tolerance +/-

Carbon

.10 min

0.01 under

0.15 max

0.01 over

Manganese, max

1.00

0.03 under

1.00

0.03 over

Phosphorus, max

0.040

0.005 over

0.040

0.005 over

Sulfur, max

0.030

0.005 over

0.03

0.005 over

Silicon

1.00 max

0.05 over

1.00 max

0.05 over

Chromium

4.00 - 6.00

0.10

11.5 - 13.50

0.15

Molybdenum

0.40 - 0.65

0.05

ASTM A193 B7, B7M, B16

Identification

B7 & B7M B16 

Grade

Chromium - Molybdenum (C4140,4142,4145,4140 H, 4142 H, 4145H)Chromium - Molybdenum - Vanadium

Element

Range

Tolerance +/-

Range

Tolerance +/-

Carbon0.37 - 0.490.020.36 - 0.440.02
Manganese0.65 - 1.100.040.45 - 0.700.03
Phosphorus, max0.0350.005 over0.0350.005 over
Sulfur, max0.0400.005 over0.0400.005 over
Silicon0.15 - 0.350.020.15 - 0.350.02
Chromium0.75 - 1.200.050.8 - 1.150.05
Molybdenum0.15 - 0.250.020.50 - 0.650.03
Vanadium--0.25 - 0.350.03
Aluminum, max%--0.015-

ASTM A193 B8, B8A

IdentificationB8, B8A B8C, B8CA 
GradeUnstabilized 18 chromium - 8 Nickel (Type 304 Stainless)Stabilized 18 Chromium- 8 Nickel (Type 347 Stainless)

Element

Range

Tolerance +/-

Range

Tolerance +/-

Carbon, max0.080.01 over0.080.01 over
Manganese, max2.000.04 over2.000.04 over
Phosphorus, max0.0450.010 over0.0450.010 over
Sulfur, max0.0300.005 over0.0300.005 over
Silicon1.000.05 over1.000.05 over
Chromium18.00 - 20.000.2017.00 - 19.000.20
Nickel8.00 - 10.500.159.00 - 13.000.15
Molybdenum-
Columbium + Tantalum-10x carbon, min0.05 under

ASTM A193 B8M, B8MA, B8M2, B8M3, B8P, B8PA

IdentificationB8M, B8MA, B8M2, B8M3 B8P, B8PA 
Grade18 Chromium- 10 Nickel- 2 Molybdenum (Type 316 Stainless)Unstabilized 18 Chromium - 8 Nickel (Type 305 Nickel)

Element

Range

Tolerance +/-

Range

Tolerance +/-

Carbon, max0.080.01 over0.120.01 over
Manganese, max2.000.04 over2.000.04 over
Phosphorus, max0.0450.010 over0.0450.010 over
Sulfur, max0.0300.005 over0.0300.005 over
Silicon1.000.05 over1.000.05 over
Chromium16.00 - 18.000.2017.00 - 19.00.20
Nickel10.00 - 14.000.1511.00 - 13.000.15
Molybdenum2.00 - 3.000.10--
Columbium + Tantalum

ASTM A193 B8N, B8NA, B8MN, B8MNA, B8MLCuN, B8MLCuNa

IdentificationB8N, B8NA B8MN, B8MNA B8MLCuN, B8MLCuNa
Grade(TYPE 304N) s 30451(TYPE 316N) s 31651S 31254

Element

Range

Tolerance +/-

Range

Tolerance +/-

Range

Carbon, max0.080.01 over0.080.01 over0.020
Manganese, max2.000.04 over2.000.04 over1.00
Phosphorus, max0.0450.010 over0.0450.010 over0.030
Sulfur, max0.0300.005 over0.0300.005 over0.010
Silicon, max1.000.05 over1.000.05 over0.80
Chromium18.00 - 20.000.2016.00 - 18.000.2019.5 - 20.5
Nickel8.00 - 10.500.1510.00 - 14.000.1517.5 18.5
Molybdenum--2.00 - 3.000.106.0 6.5
Nitrogen0.10 - 0.160.010.10 - 0.160.010.18 - 0.22
Copper----0.50 - 1.00

ASTM A193 B8T, B8TA

IdentificationB8T, B8TA 
GradeStabilized 18 Chromium - 8 Nickel (Type 321)

Element

Range

Tolerance +/-

Carbon, max0.080.01 over
Manganese, max2.000.04 over
Phosphorus, max0.0450.010 over
Sulfur, max0.0300.005 over
Silicon, max1.000.05
Nickel9.00 - 12.000.15
Chromium17.00 - 19.000.20
Titanium5 X CARBON, MIN0.05 under

ASTM A193 B8R, B8RA, B8S, B8SA

IdentificationB8R, B8RA B8S, B8SA 
Grade22 Chromium - 13 Nickel - 5 Manganese18 Chromium - 8 Nickel - 4 Silicon + Nitrogen

Element

Range

Tolerance +/-

Range

Tolerance +/-

Carbon, max0.060.01 over0.100.01 over
Manganese, max4.00 - 6.000.057.00 - 9.000.06
Phosphorus, max0.0400.005 over0.0400.005 over
Sulfur, max0.0300.005 over0.0300.005 over
Silicon1.00 MAX0.05 over3.5 - 4.50.15
Chromium20.50 - 23.500.2516.00 - 18.000.20
Nickel11.50 - 13.500.158.00 - 9.000.10
Molybdenum1.50 - 3.000.10--
Nitrogen0.20 - 0.400.020.08 - 0.180.01
Columbium + Tantalum0.10 - 0.300.05--
Vanadium0.10 - 0.300.02--

ASTM A193 B8LN, B8LNA, B8MLN, B8LNA

IdentificationB8LN, B8LNA B8MLN, B8MLNA 
GradeTYPE 304N WITH RESTRICTED CARBONTYPE 316N WITH RESTRICTED CARBON

Element

Range

Tolerance +/-

Range

Tolerance +/-

Carbon, max0.0300.005 over0.0300.005 over
Manganese, max2.000.04 over2.000.04 over
Phosphorus, max0.0450.010 over0.0450.010 over
Sulfur, max0.0300.005 over0.0300.005 over
Silicon1.000.05 over1.000.05 over
Chromium18.00 - 20.000.2016.00 - 18.000.20
Nickel8.00 - 10.500.1510.00 - 14.000.15
Molybdenum--2.00 - 3.00.10
Nitrogen0.10 - 0.160.010.10 - 0.160.01

Why Lightning Bolt ASTM A193 Specification fasteners?

Lightning Bolt & Supply has been servicing North America’s industrial fastener needs for over 25 years.  Since then, our focus on the production of high quality parts at competitive pricing has allowed us to become an industry leader.  Our niche in exotic high nickel alloy fasteners include materials such as: hastelloy, Inconel, monel, A-286, 904L, Alloy-20, duplex stainless as well as many additional alloys.  Our nearly 100,000 square feet of production space allows us to have one of the largest specialty alloy inventories in the fastener industry.

Being centrally headquartered in Baton Rouge, Louisiana, we are capable of shipping to jobsites all over the world.  Many of our industrial projects that we supply material to include anchor bolts, and also stud bolts of many different ASTM grades.  These include B7, L7, B16, B8, B8M, stain hardened and many more.  In addition to being an ISO certified fastener manufacturer, we were awarded “Corporate Supplier of the Year” by WBENC.

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