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ASTM F593 Bolting Specification

Stainless steel Bolts, Hex cap screws, and Studs intended for service applications requiring general corrosion resistance

ASTM F593 Hex Bolts, Heavy Hex Bolts, Studs, Socket Head Cap Screws, Threaded Rods

ASTM F593 specification covers the requirements for stainless steel bolts, hex cap screws, and studs 1/4 inch to 1 1/2 inch inclusive, in nominal diameter in a number of alloys in common use and intended for service applications requiring general corrosion resistance. Seven groups of stainless steel alloys are covered, including fourteen austenitic, two ferritic, four martensitic, and one precipitation hardening. Suitable nuts for use with bolts, hex cap screws, and studs included in this specification are covered by Specification F594. Unless otherwise specified, all nuts used on these fasteners shall conform to the requirements of Specification F594, shall be of the same alloy group, and shall have a specified minimum proof stress equal to or greater than the specified minimum full-size tensile strength of the externally threaded fastener. Specifications A276, A493, A564/A564M, and A582/A582M are noted for information only as suitable sources of material for the manufacture of bolts, hex cap screws, and studs to this specification.

ASTM F593 Scope

Group AlloysA ConditionB Optional Conditions (must be specified) Alloy Type
1 304, 305, 384, 304 L, (CW) cold workedC AF, A, SH Austenitic
18-9LW, 302HQ, 304J3D
2 316, 316 L CW) cold workedC
3 321, 347 (CW) cold workedC
4 430E (CW) cold workedC A Ferritic
5 410F (H) hardened and tempered HT Martensitic
6 431 (H) hardened and tempered
7 630 (AH) age hardened none Precipitation Hardening
  • A) Unless otherwise specified on the inquiry and order, the choice of an alloy from within a group shall be at the discretion of the fastener manufacturer.
  • (B) See 4.2 for options.
  • (C) Sizes 0.75 in. and larger may be hot worked and solution annealed, provided the bolts comply with the cold worked (CW) mechanical property requirements.
  • (D) When approved by the purchaser, Alloys 303, 303Se, or XM1 may be furnished.
  • (E) When approved by the purchaser, Alloy 430F may be furnished.
  • (F) When approved by the purchaser, Alloys 416 or 416Se may be furnished.
  • A - Machined from annealed or solution-annealed stock thus retaining the properties of the original material; or hot-formed and solution annealed.
  • properties of the original material; or hot-formed and solution annealed.
  • AF - Headed and rolled from annealed stock and then reannealed.
  • AH - Solution-annealed and age-hardened after forming.
  • CW - Headed and rolled from annealed stock thus acquiring a degree of cold work. Sizes 0.75 in. and larger may be hot-worked and solution-annealed.
  • H - Hardened and tempered at 1050°F (565°C) minimum.
  • HT - Hardened and tempered at 525°F (274°C) minimum.
  • SH - Machined from strain-hardened stock or cold-worked to develop the specific properties.

ASTM F593 Chemical Composition

Alloy Group Alloys
1 304, 304 L, 305, 384, 18-9LW, 302HQ, 304J3A
2 316, 316 L
3 321, 347
4 430B
5 410C
6 431
7 630
  • (A) When approved by the purchaser, Alloys 303, 303Se, or XM1 may be furnished.
  • (B) When approved by the purchaser, Alloy 430F may be furnished.
  • (C) When approved by the purchaser, Alloys 416 or 416Se may be furnished.

ASTM F593 Chemical Requirements

Alloy Group UNS Designation Alloy Carbon Manganese Phosphorus Sulfur Silicon Chromium Nickel Copper Molybdenum Others
1 S30300 303 0.15 2.00 0.20 0.15 min 1.00 17.0 to 19.0 8.0 to 10.0 . . . 0.60 maxA . . .
S30323 303 Se 0.15 2.00 0.20 0.060 1.00 17.0 to 19.0 8.0 to 10.0 . . . . . . Se 0.15 min
S30400 304 0.08 2.00 0.045 0.030 1.00 18.0 to 20.0 8.0 to 10.5 1.00 . . . . . .
S30403 304 L 0.03 2.00 0.045 0.030 1.00 18.0 to 20.0 8.0 to 12.0 1.00 . . . . . .
S30500 305 0.12 2.00 0.045 0.030 1.00 17.0 to 19.0 10.5 to 13.0 1.00 . . . . . .
S38400 384 0.08 2.00 0.045 0.030 1.00 15.0 to 17.0 17.0 to 19.0 . . . 0.50 maxA . . .
S20300 XM1 0.08 5.0 to 6.5 0.040 0.18 to 0.35 1.00 16.0 to 18.0 5.0 to 6.5 1.75 to 2.25 . . . . . .
S30430 18-9LW 0.10 2.00 0.045 0.030 1.00 17.0 to 19.0 8.0 to 10.0 3.0 to 4.0 . . . . . .
S30433 302HQ 0.03 2.00 0.045 0.030 1.00 17.0 to 19.0 8.0 to 10.0 3.0 to 4.0 . . . . . .
. . . 304J3B 0.08 2.00 0.045 0.030 1.00 17.0 to 19.0 8.0 to 10.5 1.00 to 3.00 . . . . . .
2 S31600 316 0.08 2.00 0.045 0.030 1.00 16.0 to 18.0 10.0 to 14.0 . . . 2.00 to 3.00 . . .
S31603 316 L 0.03 2.00 0.045 0.030 1.00 16.0 to 18.0 10.0 to 14.0 . . . 2.00 to 3.00 . . .
3 S32100 321 0.08 2.00 0.045 0.030 1.00 17.0 to 19.0 9.0 to 12.0 . . . . . . Ti 5× C min
S34700 347 0.08 2.00 0.045 0.030 1.00 17.0 to 19.0 9.0 to 13.0 . . . . . . Cb+Ta 10 × C min
4 S43000 430 0.12 1 0.04 0.030  1 16.0 to 18.0 . . . . . . 0.60 maxA . . .
S43020 430F 0.12 1.25 0.06 0.15 min 1 16.0 to 18.0 . . . . . . . . . . . .
5 S41000 410 0.15 1 0.04 0.03 1 11.5 to 13.5 . . . . . . 0.60 maxA Se 0.15 min
S41600 416 0.15 1.25 0.06 0.15 min 1 12.0 to 14.0 . . . . . . . . . . . .
S41623 416Se 0.15 1.25 0.06 0.06 1 12.0 to 14.0 . . . . . . . . . . . .
6 S4310 431 0.20 1.00 0.040 0.030 1.00 15.0 to 17.0 1.25 to 2.50 . . . . . . . . .
7 S17400 630 0.07 1.00 0.040 0.030 1.00 15.0 to 17.5 3.0 to 5.0 3.0 to 5.0 . . . Cb+Ta 0.15-0.45
  • (A) At manufacturer's option, determined only when intentionally added.
  • (B) 304J3 from JIS Standard G4309.

ASTM F593 Mechanical Requirements

Stainless Alloy Group ConditionB Alloy Mechanical Property Marking Nominal Diameter, in. Full-Size Tests Machined Specimen Tests
Tensile Strength ksiC Yield Strength, ksiD,C Rockwell Hardness Tensile Strength ksiC Yield Strength, ksiD,C Elongation in 4 D, %
1 (303, 304,304 L, 305,384,XM1, 18-9LW, 302HQ, 304J3, 303Se) AF F593A 1/4 to 11/2 , incl 65 to 85 20 B85 max 60 20 40
A F593B 1/4 to 11/2 , incl 75 to 100 30 B65 to 95 70 30 30
CW1 F593C 1/4 to 5/8 , incl 100 to 150 65 B95 to C32 95 60 20
CW2 F593D 3/4 to 11/2 , incl 85 to 140 45 B80 to C32 80 40 25
SH1 F593A 1/4 to 5/8 , incl 120 to 160 95 C24 to C36 115 90 12
SH2 F593B 3/4 to 1, incl 110 to 150 75 C20 to C32 105 70 15
SH3 F593C 11/8 to 11/4 , incl 100 to 140 60 B95 to C30 95 55 20
SH4 F593D 13/8 to 11/2 , incl 95 to 130 45 B90 to C28 90 40 28
2 (316,316L) AF F593E 1/4 to 11/2 , incl 65 to 85 20 B85 max 60 20 40
A F593F 1/4 to 11/2 , incl 75 to 100 30 B65 to 95 70 30 30
CW1 F593G 1/4 to 5/8 , incl 100 to 150 65 B95 to C32 95 60 20
CW2 F593H 3/4 to 11/2 , incl 85 to 140 45 B80 to C32 80 40 25
SH1 F593E 1/4 to 5/8 , incl 120 to 160 95 C24 to C36 115 90 12
SH2 F593F 3/4 to 1, incl 110 to 150 75 C20 to C32 105 70 15
SH3 F593G 11/8 to 11/4 , incl 100 to 140 60 B95 to C30 95 55 20
SH4 F593H 13/8 to 11/2 , incl 95 to 130 45 B90 to C28 90 40 28
3 (321, 347) AF F593J 1/4 to 11/2 , incl 65 to 85 20 B85 max 60 20 40
A F593K 1/4 to 11/2 , incl 75 to 100 30 B65 to 95 70 30 30
CW1 F593L 1/4 to 5/8 , incl 100 to 150 65 B95 to C32 95 60 20
CW2 F593M 3/4 to 11/2 , incl 85 to 140 45 B80 to C32 80 40 25
SH1 F593J 1/4 to 5/8 , incl 120 to 160 95 C24 to C36 115 90 12
SH2 F593K 3/4 to 1, incl 110 to 150 75 C20 to C32 105 70 15
SH3 F593L 11/8 to 11/4 , incl 100 to 140 60 B95 to C30 95 55 20
SH4 F593M 13/8 to 11/2 , incl 95 to 130 45 B90 to C28 90 40 28
4 (430, 430F) AF F593X 1/4 to 11/2 , incl 55 to 75 30 B85 max 50 25 . . .
A F593N 1/4 to 11/2 , incl 55 to 75 30 B85 max 50 25 . . .
CW1 F593V 1/4 to 5/8 , incl 60 to 105 40 B75 to 98 55 35 . . .
CW2 F593W 3/4 to 11/2 , incl 55 to 100 30 B65 to 95 50 25 . . .
5 (410, 416, 416Se) H F593P 1/4 to 11/2 , incl 110 to 140 90 C20 to 30 110 90 18
HT F593R 1/4 to 11/2 , incl 160 to 190 120 C34 to 45 160 120 12
6 (431) H F593S 1/4 to 11/2 , incl 125 to 150 100 C25 to 32 125 100 15
HT F593T 1/4 to 11/2 , incl 180 to 220 140 C40 to 48 180 140 10
7 (630) AH F593U 1/4 to 11/2 , incl 135 to 170 105 C28 to 38 135 105 16
  • (A) Minimum values except where shown as maximum or as a range.
  • (B) Legend of conditions: 
    • A-Machined from annealed or solution-annealed stock thus retaining the properties of the original material, or hot-formed and solution-annealed.
    • AF-Headed and rolled from annealed stock and then reannealed.
    • AH-Solution annealed and age-hardened after forming.
    • CW-Headed and rolled from annealed stock thus acquiring a degree of cold work; sizes 0.75 in. and larger may be hot worked and solution-annealed.
    • H-Hardened and tempered at 1050°F (565°C) minimum.
    • HT-Hardened and tempered at 525°F (274°C) minimum.
    • SH-Machined from strain hardened stock or cold-worked to develop the specified properties.
  • (C) The yield and tensile strength values for full-size products shall be computed by dividing the yield and maximum tensile load values by the stress area for the product size and thread series determined in accordance with Test Methods F606/F606M.
  • (D) Yield strength is the stress at which an offset of 0.2 % gage length occurs.

Mechanical Test Requirements for Bolts and Studs

Item Nominal Length Tensile Load, lbf Full-Size Tests Machined Specimen Tests
Diameters3/4in. and Less Diameters Over3/4in. Wedge Tensile Strength Axial Tensile Strength Yield Strength Rockwell Hardness Tensile Strength Yield Strength Elongation
Square and hexbolts and hexcap screws less than 21/4D less than 3D all Option A B B Option C B B B
21/4Dand longer 3Dand longer 120000 max mandatory B mandatory B B B B
over 120000 Option A B Option A B Option B Option B Option B
Studs and otherbolts less than 21/4D less than 3D all B Option A B Option C B B B
21/4Dand longer 3D and longer 120000 max B mandatory mandatory B B B B
over 120000 B Option A Option A B Option B Option B Option B
SpecialsC all all all B B B mandatory B B B
  • (A) Where options are given, all the tests under an option shall be performed. Option A, Option B, and Option C indicates manufacturer may perform all Option A (full-size), all Option B (machined specimen), or all Option C tests whichever is preferred. Option A tests should be made whenever feasible.
  • (B) Tests that are not mandatory.
  • (C) Special fasteners are those fasteners with special configurations including drilled heads, reduced body, etc., that are weaker than the threaded section. Special fasteners having full-size heads shall be tested as specified for studs and other bolts.

Tensile Stress Areas and Threads (Inch)

Nominal Size, in. (D) Coarse Threads-UNC Fine Threads-UNF Thread Series-8 UN
Threads/in. Stress AreaA, in.2 Threads/in. Stress AreaA, in.2 Threads/in. Stress AreaA, in.2
1/4 (0.250) 20 0.0318 28 0.0364 . . . . . .
5/16 (0.3125) 18 0.0524 24 0.0580 . . . . . .
3/18 (0.375) 16 0.0775 24 0.0878 . . . . . .
7/16 (0.4375) 14 0.1063 20 0.1187 . . . . . .
1/2 (0.500) 13 0.1419 20 0.1599 . . . . . .
9/16 (0.5625) 12 0.1820 18 0.2030 . . . . . .
5/8 (0.625) 11 0.2260 18 0.2560 . . . . . .
3/4 (0.750) 10 0.3340 16 0.3730 . . . . . .
7/8 (0.875) 9 0.4620 14 0.5090 . . . . . .
1.000 8 0.6060 12 0.6630 . . . . . .
11/8 (1.125) 7 0.7630 12 0.8560 8 0.790
11/4 (1.250) 7 0.9690 12 1.0730 8 1.000
13/8 (1.375) 6 1.1550 12 1.3150 8 1.233
11/2 (1.500) 6 1.4050 12 1.5810 8 1.492
  • (A) Tensile stress areas are computed using the following formula:
  • As = 0.7854 [D - 0.9743/n]2
  • where:
  • As = tensile stress area, in.2,
  • D = nominal size (basic major diameter), in., and
  • n = number of threads per inch.

ASTM F593 Bolting Surface Treatment Specifications

ASTM F593 Bolting Components Marking

Product Shall be Marked with our manufacturing trade mark "TorqBolt" or "TB" along with the designated Grade.
Grade and manufacturer’s identification symbols shall be applied to one end of studs and to the heads of bolts and screws of all sizes. (If the available area is inadequate, the grade symbol may be marked on one end and the manufacturer’s identification symbol marked on the other end.) For bolts and screws 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 the manufacturer.

ASME Dimensional Standards

B18.31.2 Imperial Continious Thread, Double End Reduced & Full Body Studs
B18.31.3 Threaded Rods (Inch Series)
B16.5 Imperial Full Thread Stud Bolts
B16.5 Metric Full Thread Stud Bolts
B18.2.1 Imperial Square and Hex Bolts and Screws
B18.3 Imperial Hexagon Socket and Spline Socket Screws

ASTM F593 Bolting Certifications

  • EN 10204 3.1
  • EN 10204 3.2
  • PED 2014/68/EC
  • MERKBLATT AD 2000 W2/W7/W10
  • API 20 E BSL 1/ BSL 2
  • NACE MR 0175
  • NACE MR 0103

ASTM F593 Testing Standards

E18 Test Methods for Rockwell Hardness of Metallic Materials
E21 Test Methods for Elevated Temperature Tension Tests of Metallic Materials
E112 Test Methods for Determining Average Grain Size
E139 Test Methods for Conducting Creep, Creep-Rupture,and Stress-Rupture Tests of Metallic Materials
E150 Recommended Practice for Conducting Creep and Creep-Rupture Tension Tests of Metallic Materials Under Conditions of Rapid Heating and Short Times
E151 Recommended Practice for Tension Tests of Metallic Materials at Elevated Temperatures with Rapid Heating and Conventional or Rapid Strain Rates
E292 Test Methods for Conducting Time-for-Rupture Notch Tension Tests of Materials
E328 Test Methods for Stress Relaxation for Materials and Structures
E566 Practice for Electromagnetic (Eddy Current) Sorting of Ferrous Metals
E709 Guide for Magnetic Particle Testing
F606/F606M Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets
F1940 Test Method for Process Control Verification to Prevent Hydrogen Embrittlement in Plated or Coated Fasteners
A962/A962M Specification for Common Requirements for Bolting Intended for Use at Any Temperature from Cryogenic to the Creep Range
A788/A788M for Steel Forgings, General Requirements

ASME Threading Specifications

ASME B1.1 Unified Inch Screw Threads (UN and UNR Thread Form)
ASME B1.3 Screw Thread Gaging System for Dimensional Acceptability - Inch Screw Threads (IN, UNR, and UNJ)