ASTM F593 is the Standard Specification for Stainless Steel Bolts, Hex Cap Screws and Stud Bolts. This specification covers imperial sizes from 1/4 inch to 1-1/2 inches and includes seven alloy groups comprising twelve austenitic, two ferritic, four martensitic and one precipitation hardening stainless steel alloy. These fasteners are specified for applications requiring general corrosion resistance and mechanical properties suitable for service environments across industries including chemical processing, food & beverage, marine hardware, architectural construction and water treatment.
Jade Alloys manufactures these ASTM F593 fasteners in hex bolts, stud bolts, threaded rods, socket head cap screws, U-bolts, lag bolts, eye bolts, and other configurations. All fasteners must be tested and certified to EN 10204 Type 3.1 or 3.2 standards.
ASTM F593 Supply Conditions
ASTM F593 bolts are supplied in four distinct supply conditions that define the heat treatment, cold working, and mechanical property levels. The condition marking appears on the bolt head or packaging and is critical for proper specification.
| Condition Code | Definition | Applicable Alloy Groups | Typical Applications |
|---|---|---|---|
| AF | As Fabricated (annealed or hot worked) | Groups 1, 2, 3, 4 | Maximum ductility, lowest strength applications |
| A | Annealed or Solution Treated | Groups 1, 2, 3, 4 | General corrosion resistance, moderate strength |
| CW | Cold Worked (strain hardened) | Groups 1, 2, 3, 4 | Higher strength than annealed, reduced ductility |
| SH | Strain Hardened (high cold work) | Groups 1, 2, 3 | Maximum strength in austenitic alloys |
| H | Hardened and Tempered | Groups 5, 6 | Martensitic alloys, heat-treated for strength |
| AH | Age Hardened (precipitation hardening) | Group 7 (630) | 17-4 PH stainless steel, heat-treated |
Legend: AF = As Fabricated (annealed or hot worked) — lowest strength, maximum ductilityA = Annealed or Solution Treated — baseline condition for austenitic alloysCW = Cold Worked — strain hardened to increase tensile and yield strengthSH = Strain Hardened — highest strength austenitic condition, cold worked beyond CW levelsH = Hardened and Tempered — heat-treated martensitic alloysAH = Age Hardened — precipitation hardening treatment for 630 (17-4 PH) alloy
ASTM F593 Alloy Groups
ASTM F593 categorizes stainless steel alloys into seven groups based on metallurgical structure and composition. Each group includes specific alloys with defined supply conditions and mechanical properties.
| Group | Alloys | Condition |
|---|---|---|
| 1 | 304, 305, 384, 304L, 18-9LW, 302HQ | AF, A, CW, SH |
| 2 | 316, 316L | AF, A, CW, SH |
| 3 | 321, 347 | AF, A, CW, SH |
| 4 | 430, 430F | AF, A, CW |
| 5 | 410, 416, 416Se | H (Hardened and Tempered) |
| 6 | 431 | H (Hardened and Tempered) |
| 7 | 630 (17-4 PH) | AH (Age Hardened) |
Tensile Stress Area for ASTM F593 Bolts
The tensile stress area (At) is the effective cross-sectional area used to calculate bolt tension, clamp load, and proof load. Values vary by thread series (UNC, UNF, 8UN) and are critical for torque calculations and structural design.
| Nominal Size | UNC (sq in) | UNF (sq in) | 8UN (sq in) |
|---|---|---|---|
| 1/4″ | 0.0318 | 0.0364 | — |
| 5/16″ | 0.0524 | 0.0580 | — |
| 3/8″ | 0.0775 | 0.0878 | — |
| 7/16″ | 0.1063 | 0.1187 | — |
| 1/2″ | 0.1419 | 0.1599 | 0.1450 |
| 9/16″ | 0.1819 | 0.2030 | — |
| 5/8″ | 0.2260 | 0.2560 | 0.2260 |
| 3/4″ | 0.3340 | 0.3730 | 0.3510 |
| 7/8″ | 0.4620 | 0.5090 | 0.4800 |
| 1″ | 0.6060 | 0.6630 | 0.6250 |
| 1-1/8″ | 0.7630 | 0.8560 | 0.7900 |
| 1-1/4″ | 0.9690 | 1.0730 | 1.0000 |
| 1-3/8″ | 1.1550 | 1.3150 | 1.2330 |
| 1-1/2″ | 1.4050 | 1.5810 | 1.4920 |
ASTM F593 Chemical Composition
Chemical composition requirements per ASTM F593 for all austenitic, ferritic, martensitic, and precipitation hardening alloys. Composition values are % maximum except where shown as ranges.
| Alloy | UNS | C Max | Cr | Ni | Mo | Others |
|---|---|---|---|---|---|---|
| 304 | S30400 | 0.08 | 18.0-20.0 | 8.0-10.5 | — | — |
| 304L | S30403 | 0.03 | 18.0-20.0 | 8.0-12.0 | — | — |
| 316 | S31600 | 0.08 | 16.0-18.0 | 10.0-14.0 | 2.0-3.0 | — |
| 316L | S31603 | 0.03 | 16.0-18.0 | 10.0-14.0 | 2.0-3.0 | — |
| 321 | S32100 | 0.08 | 17.0-19.0 | 9.0-12.0 | — | Ti ≥5×C |
| 347 | S34700 | 0.08 | 17.0-19.0 | 9.0-13.0 | — | Nb ≥10×C |
| 410 | S41000 | 0.15 | 11.5-13.5 | — | — | — |
| 630 | S17400 | 0.07 | 15.0-17.5 | 3.0-5.0 | — | Nb 0.15-0.45 |
Mechanical Properties of ASTM F593 Bolts
Mechanical properties per ASTM F593 including tensile strength, yield strength, elongation, and hardness by alloy group, supply condition, and nominal diameter. Properties govern pressure class suitability and load-bearing capacity.
| Alloy Group | Condition | Size Range | Tensile (ksi) | Yield (ksi) | Elongation (%) |
|---|---|---|---|---|---|
| 1 (304) | CW1 | 1/4 to 5/8″ | 100-150 | 65 | 20 |
| 1 (304) | CW2 | 3/4 to 1-1/2″ | 85-140 | 45 | 25 |
| 2 (316) | CW1 | 1/4 to 5/8″ | 100-150 | 65 | 20 |
| 2 (316) | CW2 | 3/4 to 1-1/2″ | 85-140 | 45 | 25 |
| 5 (410) | H | 1/4 to 1-1/2″ | 110-140 | 90 | 18 |
| 7 (630) | AH | 1/4 to 1-1/2″ | 135-170 | 105 | 16 |
ASTM F593 Hex Bolt Dimensions
Dimensional specifications per ASME B18.2.1 for ASTM F593 hex head bolts including body diameter, head height, across flats (F), across corners (C), and thread lengths.
Inch Series Dimensions
| Diameter | Body Dia MAX | Head Height MAX | Across Flats MAX | Across Corners MAX |
|---|---|---|---|---|
| 1/4″ | 0.260 | 0.188 | 0.438 | 0.505 |
| 5/16″ | 0.324 | 0.220 | 0.500 | 0.577 |
| 3/8″ | 0.388 | 0.268 | 0.563 | 0.650 |
| 1/2″ | 0.515 | 0.364 | 0.875 | 1.010 |
| 5/8″ | 0.642 | 0.444 | 1.062 | 1.227 |
| 3/4″ | 0.768 | 0.524 | 1.250 | 1.443 |
| 1″ | 1.022 | 0.700 | 1.625 | 1.876 |
| 1-1/4″ | 1.277 | 0.876 | 2.000 | 2.309 |
| 1-1/2″ | 1.531 | 1.036 | 2.375 | 2.742 |
Metric Series Dimensions
| Size | Body Dia MAX | Head Height MAX | Across Flats MAX | Across Corners MAX |
|---|---|---|---|---|
| M10 | 10.00 | 6.63 | 17.00 | 18.48 |
| M12 | 12.00 | 7.76 | 19.00 | 20.78 |
| M16 | 16.00 | 10.32 | 24.00 | 27.71 |
| M20 | 20.00 | 12.88 | 30.00 | 34.64 |
| M24 | 24.00 | 15.44 | 36.00 | 41.57 |
| M30 | 30.00 | 19.48 | 46.00 | 53.12 |
ASTM F593 Torque Specifications
Recommended torque values for ASTM F593 bolts and threaded rods showing 30% initial torque, 70% intermediate torque, and 100% final torque in both FT-LBS and Newton-meters (Nm). These values assume clean, dry threads with no lubricant and should be adjusted based on actual friction conditions and assembly requirements.
| Bolt Diameter | 30% Initial (FT-LBS) | 70% (FT-LBS) | 100% Final (FT-LBS) | 30% Initial (Nm) | 100% Final (Nm) |
|---|---|---|---|---|---|
| 1/2″ | 16 | 36 | 52 | 22 | 71 |
| 5/8″ | 31 | 73 | 104 | 42 | 141 |
| 3/4″ | 55 | 129 | 184 | 75 | 249 |
| 7/8″ | 71 | 166 | 237 | 96 | 321 |
| 1″ | 107 | 249 | 356 | 145 | 483 |
| 1-1/4″ | 179 | 417 | 596 | 243 | 808 |
| 1-1/2″ | 246 | 574 | 821 | 334 | 1113 |
Equivalent International Standards
International equivalent grades for ASTM F593 alloys across UNS, EN/DIN, AISI, and other global standards.
| ASTM F593 Alloy | UNS | AISI | EN/DIN | JIS |
|---|---|---|---|---|
| 304 | S30400 | 304 | X5CrNi18-10 (1.4301) | SUS 304 |
| 304L | S30403 | 304L | X2CrNi18-9 (1.4307) | SUS 304L |
| 316 | S31600 | 316 | X5CrNiMo17-12-2 (1.4401) | SUS 316 |
| 316L | S31603 | 316L | X2CrNiMo17-12-2 (1.4404) | SUS 316L |
| 321 | S32100 | 321 | X6CrNiTi18-10 (1.4541) | SUS 321 |
| 630 (17-4) | S17400 | 630 | X5CrNiCuNb16-4 (1.4542) | SUS 630 |
Types of ASTM F593 Fasteners
ASTM F593 fasteners are manufactured in multiple configurations including hex bolts, heavy hex bolts, stud bolts, threaded rods, socket head cap screws, U-bolts, eye bolts, lag bolts, flange bolts, and square head bolts. Each type must conform to the material, mechanical property, and dimensional requirements specified in ASTM F593.
Applications of ASTM F593 Fasteners
ASTM F593 bolts are specified across industries requiring corrosion-resistant stainless steel fasteners with defined mechanical properties and chemical composition.
- Water & Wastewater Treatment: Pumps, valves, filtration equipment
- Food & Beverage Processing: Hygienic equipment, tank connections, conveyor systems
- Chemical Processing: Reactor vessels, piping systems, heat exchangers
- Architectural & Construction: Curtain walls, railings, structural connections
- Marine Hardware: Deck fittings, rigging, offshore platforms
- Power Generation: Boilers, turbines, cooling towers
- Petrochemical: Refinery equipment, process vessels, piping flanges
ASTM F593 Thread Requirements
Thread specifications per ASME B1.1 for unified inch threads (UNC and UNF) and ASME B1.13M for metric threads (6h tolerance class). Standard thread class is Class 2A for inch fasteners and 6h for metric fasteners. Class 3A threads available on request for tighter tolerance requirements.
Frequently Asked Questions
What nuts are compatible with ASTM F593 bolts?
ASTM F593 bolts require ASTM F594 hex nuts of matching stainless steel alloy group and supply condition. For example, an F593 Group 1 (304) bolt in CW condition should be paired with an F594 Group 1 nut in CW1 or CW2 condition depending on diameter. Never mix austenitic bolts with martensitic nuts — galvanic corrosion will occur.
What is the difference between ASTM A193 and ASTM F593?
ASTM A193 covers hot-forged stainless steel bolts for high-temperature service (primarily pressure vessels and boilers). ASTM F593 covers cold-formed and strain-hardened stainless steel bolts for general corrosion resistance at ambient temperatures. A key difference: F593 requires intergranular corrosion susceptibility testing (per ASTM A262 Practice E), which is not required in A193.
What does the condition marking on F593 bolts mean?
The condition marking (AF, A, CW, SH, H, AH) indicates the heat treatment and cold working history of the fastener, which directly controls tensile strength, yield strength, and ductility. For example, CW (Cold Worked) means the bolt was strain hardened after annealing to increase strength. SH (Strain Hardened) is even higher strength than CW. The condition must match your design load requirements.
Can ASTM F593 bolts be used in high-temperature applications?
ASTM F593 bolts are not recommended for sustained high-temperature service above 800°F (427°C). For elevated temperature applications, specify ASTM A193 Grade B8 (304) or B8M (316) instead. A193 bolts are hot-forged and have verified high-temperature mechanical properties, whereas F593 is specified for ambient to moderate temperatures.
Related Products
ASTM F593 Bolts Supplier & Manufacturer
Jade Alloys manufactures and supplies ASTM F593 bolts, stud bolts, hex cap screws, and threaded rods in all alloy groups (1-7) and supply conditions (AF, A, CW, SH, H, AH). All fasteners are manufactured from certified mill material and supplied with EN 10204 Type 3.1 Material Test Certificates. Third-party inspection available on request.
