ASTM F594 Specification for Stainless Steel Nuts
ASTM F594 includes chemical and mechanical specifications of stainless steel nutswith a diameter of 1/4 -1-1/2 inclusive and in use with fasteners meeting ASTM F593. These ASTM F594 Nuts are general purpose nuts that are offered in seven alloy groups. The following is a rudimentary outline of the typical grades of the ASTM F594 specification.
ASTM F594 standard outlines the specifications of stainless steel hex nut in imperial sizes of between 1/4 inch to 1 1/2 inches. This specification is important to service applications that need general corrosion resistance and can cover a large spectrum of alloys, comprising seven different groups of stainless steel. These are further subdivided into twelve austenitic, two ferritic, four martensitic and one precipitation hardening alloy type. These nuts are commonly referred to as F594A, F594C, F594D, F594F, F594G and F594H, which are also commonly made. Jade Alloys manufactures these hex nuts according to the ASTM standard, ensuring they are duly tested and supplied with EN 10204 Type 3.1 Certification.
Quick Section Links
- ASTM F594 Specification for Stainless Steel Nuts
- ASTM F594 Stainless Steel Nuts Manufacturer & Supplier in India
- Quality Certifications
- ASTM F594 Alloy Groups
- Types of ASTM F594 Fasteners
- ASTM F594 Nuts Specifications
- ASTM F594 Chemical Composition
- ASTM F594 Mechanical Properties by Condition
- ASTM F594 Equivalent Grades
- ASTM F594 Hex Nut Dimensions (Imperial)
- ASTM F594 Heavy Hex Nut Dimensions (Imperial)
- ASTM F594 Nut Size Chart – Metric (M2 to M20)
- Heat Treatment Temperatures of ASTM F594 Nuts
- ASTM A594 Nuts Inventory
- Manufacturing Process & Quality Assurance
- What is the difference between ASTM F594 and A194?
- Applications of ASTM F594 Stainless Steel Nuts
- Frequently Asked Questions
- ASTM F594 Nuts Price in India
ASTM F594 Stainless Steel Nuts Manufacturer & Supplier in India
Jade Alloys is a leading manufacturer, stockist, and exporter of ASTM F594 Stainless Steel Nuts, based in Mumbai, India. We supply to 50+ countries worldwide with EN 10204 Type 3.1 Mill Test Certificates on every shipment.
ASTM F594 covers chemical and mechanical requirements for stainless steel nuts in imperial sizes 1/4″ to 1-1/2″. It covers seven alloy groups spanning austenitic, ferritic, martensitic, and precipitation-hardening stainless steels, designed for use with ASTM F593 bolts in general-purpose corrosion-resistant applications.
Quality Certifications
ISO 9001:2015
Quality Management System Certified
Third-party certified QMS covering manufacturing, inspection, and dispatch.
PED 97/23/EC
Pressure Equipment Directive
EU export-ready compliance for pressure equipment requirements.
NACE MR0175 / ISO 15156
Sour Service / H₂S Environment
Approved for hydrogen-sulfide environments used in oil & gas industries.
EN 10204 Type 3.1
Material Test Certificate
Complete traceability verified by independent third-party inspection.
AD 2000 Merkblatt W2
German Pressure Vessel Standard
Engineered to meet German requirements for pressure-bearing fasteners.
ASTM F594 Alloy Groups
ASTM F594 covers seven alloy groups. Each group designates a family of stainless steels sharing similar corrosion-resistance characteristics and heat-treatment conditions.
| Group | Alloys Covered | Condition |
|---|---|---|
| 1 | 304, 305, 384, 304L, 18-9LW, 302HQ | (CW) Cold Worked |
| 2 | 316, 316L | (CW) Cold Worked |
| 3 | 321, 347 | (CW) Cold Worked |
| 4 | 430F | (CW) Cold Worked |
| 5 | 410F | (H) Hardened & Tempered |
| 6 | 431 | (H) Hardened & Tempered |
| 7 | 630 | (AH) Age Hardened |
Types of ASTM F594 Fasteners
ASTM F594 Hex Nuts
ASTM F594 Heavy Hex Nuts
ASTM F594 Lock Nuts
ASTM F594 Coupling Nuts
ASTM F594 Square Nuts
ASTM F594 Flange Nuts
ASTM F594 Acorn / Dome Nuts
ASTM F594 Wing Nuts
ASTM F594 Panel Nuts / T-Slot Nuts
ASME SF594 Eye Nuts
ASTM F594 Slotted / Castle Nuts
ASTM F594 Serrated Flange Nuts
ASTM F594 Nylon Insert (Nylock) Nuts
ASTM F594 2-Way Lock Nuts
ASTM F594 Nuts Specifications
| Parameter | Details |
|---|---|
| Standard | ASTM F594 |
| Dimensions | ASME B18.2.1, B18.3 |
| Thread Configuration | ASME B1.1 2A/3A Inch Unified & B1.13M 6h Metric Coarse |
| Melt Origin | East Europe / South America / Korea / Japan |
| Product Origin | Made in India |
| Certification | Dual Certified — ASTM & ASME Codes |
| Additional Certifications | PED 97/23/EC, Merkblatt AD 2000 W2 |
| Coatings | Black Oxide, Cadmium, Galvanized, Teflon, Xylan, Zinc |
| Mandatory Requirements | Free from Mercury & Radioactive Contamination |
| Additional Requirements | NACE MR0103 / MR0175 / ISO 15156 Compliance |
| Delivery Time | Regular: 7-15 days; Custom: per requirement |
ASTM F594 Chemical Composition
The table below shows elemental composition limits for the two most common alloy groups. Groups 3-7 have separate composition requirements defined in the full ASTM F594 standard.
| Element (max unless noted) | Group 1 — Type 304 | Group 2 — Type 316 |
|---|---|---|
| Carbon | 0.08% | 0.08% |
| Manganese | 2.00% | 2.00% |
| Phosphorus | 0.045% | 0.045% |
| Sulfur | 0.030% | 0.030% |
| Silicon | 1.00% | 1.00% |
| Chromium | 18.0 to 20.0% | 16.0 to 18.0% |
| Nickel | 8.0 to 10.5% | 10.0 to 14.0% |
| Copper | 1.00% | — |
| Molybdenum | — | 2.00 to 3.00% |
ASTM F594 Mechanical Properties by Condition
The following table details proof stress and hardness values for Groups 1 and 2. The marking code (e.g. F594A, F594C) is stamped on each nut and identifies the alloy group and condition for full field traceability.
| Alloy Group | Condition | Marking | Diameter Range | Proof Stress Hex Nuts (ksi) | Proof Stress Heavy Hex (ksi) | Rockwell Hardness |
|---|---|---|---|---|---|---|
| 1 | AF | F594A | 1/4 to 1-1/2 | 70 | 76 | B85 max |
| 1 | A | F594B | 1/4 to 1-1/2 | 75 | 81 | B65 to 95 |
| 1 | CW1 | F594C | 1/4 to 5/8 | 100 | 108 | B95 to C32 |
| 1 | CW2 | F594D | 3/4 to 1-1/2 | 85 | 92 | B80 to C32 |
| 2 | AF | F594E | 1/4 to 1-1/2 | 70 | 76 | B85 max |
| 2 | A | F594F | 1/4 to 1-1/2 | 75 | 81 | B65 to 95 |
| 2 | CW1 | F594G | 1/4 to 5/8 | 100 | 108 | B95 to C32 |
| 2 | CW2 | F594H | 3/4 to 1-1/2 | 85 | 92 | B80 to C32 |
AF = Annealed & Fully Softened | A = Annealed | CW1 = Cold Worked (small sizes) | CW2 = Cold Worked (large sizes)
ASTM F594 Equivalent Grades
Cross-reference F594 designations with international standards including UNS, EN/DIN, ISO 3506-2, and JIS.
| Alloy Group | Common Grade | F594 Marking | UNS | EN/DIN W.Nr. | ISO Property Class | JIS |
|---|---|---|---|---|---|---|
| Group 1 | 304 SS | F594A/B/C | S30400 | 1.4301 | A2-70, A2-80 | SUS 304 |
| Group 1 | 304L SS | F594A/B/D | S30403 | 1.4307 | A2-70, A2-80 | SUS 304L |
| Group 2 | 316 SS | F594E/F/G | S31600 | 1.4401 | A4-70, A4-80 | SUS 316 |
| Group 2 | 316L SS | F594E/F/H | S31603 | 1.4404/1.4435 | A4-70, A4-80 | SUS 316L |
| Group 3 | 321 SS | F594J/K/L | S32100 | 1.4541 | A3 or A5 | SUS 321 |
| Group 3 | 347 SS | F594J/K/M | S34700 | 1.4550 | A3 or A5 | SUS 347 |
| Group 4 | 430 SS | F594N/V | S43000 | 1.4016 | F1 | SUS 430 |
| Group 5 | 410 SS | F594P/R | S41000 | 1.4006 | C1, C3 | SUS 410 |
| Group 7 | 630 (17-4PH) | F594U | S17400 | 1.4542 | — | SUS 630 |
ASTM F594 Hex Nut Dimensions (Imperial)
All dimensions in inches. Compliant with ASME B18.2.2. Width Across Corners (G) values show the Max-Min range.
| Nominal Size | Thread Diameter | Width Across Flats (F) | Width Across Corners (G) Max-Min | Thickness (H) |
|---|---|---|---|---|
| 1/4 | 0.2500 | 7/16 | 0.505 to 0.488 | 0.505 |
| 5/16 | 0.3125 | 1/2 | 0.577 to 0.557 | 0.577 |
| 3/8 | 0.3750 | 9/16 | 0.650 to 0.628 | 0.650 |
| 1/2 | 0.5000 | 3/4 | 0.866 to 0.840 | 0.866 |
| 9/16 | 0.5625 | 7/8 | 1.010 to 0.982 | 1.010 |
| 5/8 | 0.6250 | 15/16 | 1.083 to 1.051 | 1.083 |
| 3/4 | 0.7500 | 1-1/8 | 1.299 to 1.240 | 1.299 |
| 7/8 | 0.8750 | 1-5/16 | 1.516 to 1.447 | 1.516 |
| 1 | 1.0000 | 1-1/2 | 1.732 to 1.653 | 1.732 |
| 1-1/8 | 1.1250 | 1-11/16 | 1.949 to 1.859 | 1.949 |
| 1-3/8 | 1.3750 | 2-1/16 | 2.382 to 2.273 | 2.382 |
| 1-1/2 | 1.5000 | 2-1/4 | 2.598 to 2.480 | 2.598 |
ASTM F594 Heavy Hex Nut Dimensions (Imperial)
Heavy hex nuts have a larger wrench flat and greater thickness than standard hex nuts. All values in inches per ASME B18.2.2.
| Nominal Size | Thread Dia. | WAF Basic | WAF Max | WAF Min | WAC Max | WAC Min | Thick Basic | Thick Max | Thick Min |
|---|---|---|---|---|---|---|---|---|---|
| 1/4 | .2500 | 1/2 | .500 | .488 | .577 | .556 | 15/64 | .250 | .218 |
| 5/16 | .3125 | 9/16 | .562 | .546 | .650 | .622 | 19/64 | .314 | .280 |
| 3/8 | .3750 | 11/16 | .688 | .669 | .794 | .763 | 23/64 | .377 | .341 |
| 7/16 | .4375 | 3/4 | .750 | .728 | .866 | .830 | 27/64 | .441 | .403 |
| 1/2 | .5000 | 7/8 | .875 | .850 | 1.010 | .969 | 31/64 | .504 | .464 |
| 5/8 | .6250 | 1-1/16 | 1.062 | 1.031 | 1.227 | 1.175 | 39/64 | .631 | .587 |
| 3/4 | .7500 | 1-1/4 | 1.250 | 1.212 | 1.443 | 1.382 | 47/64 | .758 | .710 |
| 1 | 1.0000 | 1-5/8 | 1.625 | 1.575 | 1.876 | 1.796 | 63/64 | 1.012 | .956 |
| 1-1/4 | 1.2500 | 2 | 2.000 | 1.938 | 2.309 | 2.209 | 1-7/32 | 1.251 | 1.187 |
| 1-1/2 | 1.5000 | 2-3/8 | 2.375 | 2.300 | 2.742 | 2.622 | 1-15/32 | 1.505 | 1.433 |
| 2 | 2.0000 | 3-1/8 | 3.125 | 3.025 | 3.608 | 3.449 | 1-31/32 | 2.013 | 1.925 |
| 2-1/2 | 2.5000 | 3-7/8 | 3.875 | 3.750 | 4.474 | 4.275 | 2-29/64 | 2.505 | 2.401 |
| 3 | 3.0000 | 4-5/8 | 4.625 | 4.475 | 5.340 | 5.102 | 2-61/64 | 3.013 | 2.893 |
| 4 | 4.0000 | 6-1/8 | 6.125 | 5.925 | 7.073 | 6.755 | 3-15/16 | 4.014 | 3.862 |
WAF = Width Across Flats | WAC = Width Across Corners
ASTM F594 Nut Size Chart – Metric (M2 to M20)
Although ASTM F594 is primarily an imperial standard, metric equivalents are frequently requested. The table below provides dimensions for metric-equivalent F594 stainless steel nuts.
| Size (mm) | Dia. Across Flats (mm) | Hex Nut Height (mm) | Jam Nut Height (mm) | Nylock Nut Height (mm) |
|---|---|---|---|---|
| M2 | 4 | 1.6 | 1.2 | — |
| M2.5 | 5 | 2 | 1.6 | — |
| M3 | 5.5 | 2.4 | 1.8 | 4 |
| M4 | 7 | 3.2 | 2.2 | 5 |
| M5 | 8 | 4 | 2.7 | 5 |
| M6 | 10 | 5 | 3.2 | 6 |
| M7 | 11 | 5.5 | 3.5 | — |
| M8 | 13 | 6.5 | 4 | 8 |
| M10 | 17 | 8 | 5 | 10 |
| M12 | 19 | 10 | 6 | 12 |
| M14 | 22 | 11 | 7 | 14 |
| M16 | 24 | 13 | 8 | 16 |
| M18 | 27 | 15 | 9 | 18.5 |
| M20 | 30 | 16 | 10 | 20 |
Thread Specifications
ASTM F594 nuts are produced in two thread systems:
- Inch Unified Threads: ASME B1.1, Class 2B (standard) and 3B (close tolerance) — UNC form for most sizes.
- Metric Threads: ASME B1.13M, Class 6H — Coarse-pitch metric threads per ISO 262.
Go/No-Go thread gauges are used during 100% in-process inspection at our Mumbai facility.
Coating & Surface Finish Options
Standard F594 nuts are supplied in the as-manufactured (bright) condition. Additional surface treatments available on request:
- Black Oxide — mild corrosion resistance; maintains tight dimensional tolerances.
- Galvanized (Hot-Dip or Electro) — zinc coating for atmospheric corrosion protection.
- Teflon (PTFE) — chemical resistance; reduces galling risk during installation.
- Xylan — dry-film fluoropolymer; excellent for sour-service environments.
- Zinc Plating — cost-effective electroplated zinc for mild-exposure applications.
- Cadmium Plating — available on request for aerospace and military specifications.
Heat Treatment Temperatures of ASTM F594 Nuts
Heat treatment conditions are determined by alloy class, as required by ASTM F594.
| Alloy Type | Alloys Covered | Heat Treatment Temperature |
|---|---|---|
| Austenitic | 303, 304, 304L, 305, 316, 316L, 321, 347 | 1900 +/- 50 deg F (1038 +/- 28 deg C) |
| Ferritic | 430, 430F | 1450 +/- 50 deg F (788 +/- 28 deg C) |
| Martensitic | 410, 416, 416Se | 1850 +/- 50 deg F (1010 +/- 28 deg C) |
| Precipitation Hardening | 630 (17-4PH) | 1038 +/- 14 deg C (Age Hardening) |
ASTM A594 Nuts Inventory
ASTM F594 Hex Nuts
ASTM F594 Lock Nuts
ASTM F594 Wing Nuts
Manufacturing Process & Quality Assurance
Cold Forming vs Hot Forging
Most F594 nuts in sizes 1/4″ to 1″ are produced by cold forming — a process that work-hardens the material and produces tight dimensional tolerances. Larger sizes (1-1/8″ and above) may be hot forged and finish-machined.
Quality Testing at Jade Alloys
Our Mumbai facility conducts the following inspections on every batch:
- Dimensional inspection: micrometers, thread gauges (Go/No-Go), optical comparators.
- Hardness testing: Rockwell B/C scale to verify condition compliance.
- Proof load testing: hydraulic fixtures for 100% lot verification on critical orders.
- Tensile testing: universal testing machine to verify proof stress values per ASTM F594.
- Chemical analysis: optical emission spectrometry (OES) to verify alloy composition.
- Surface finish: visual inspection and surface roughness measurement.
All test records are retained for 10+ years and supplied with each shipment as part of the EN 10204 3.1 MTC.
What is the difference between ASTM F594 and A194?
Both F594 and A194 are ASTM nut standards but serve distinct applications. Use this table to determine which to specify.
| Feature | ASTM F594 | ASTM A194 |
|---|---|---|
| Material | Stainless steel (7 alloy groups) | Carbon & alloy steel (multiple grades) |
| Primary Use | General-purpose corrosion-resistant fastening | High-temperature & high-pressure service |
| Size Range | 1/4 in. to 1-1/2 in. imperial | 1/4 in. to 4 in. and larger |
| Alloy Types | Austenitic, ferritic, martensitic, PH | Carbon steel, alloy steel, stainless |
| Marking System | F594A through F594U by condition & group | Grade + number (e.g. 2H, 8, 8M) |
| Common Pairing | Used with ASTM F593 bolts | Used with A193 stud bolts |
Specify F594 for general corrosion-resistant applications with stainless steel bolts (F593). Specify A194 for elevated temperature, high pressure, or carbon/alloy steel grades.
Applications of ASTM F594 Stainless Steel Nuts
- Oil & Gas: wellhead equipment, pipeline flanges, subsea assemblies, offshore platforms.
- Chemical & Petrochemical: reactors, heat exchangers, pressure vessels, corrosive fluid handling.
- Power Generation: turbine casing studs, condenser joints, cooling water systems.
- Nuclear Energy: containment structures and reactor auxiliary systems requiring traceable fasteners.
- Marine & Offshore: deck hardware, hull fittings, mooring equipment exposed to seawater.
- Pharmaceutical & Food Processing: sanitary fittings, mixing vessels, clean-room equipment.
- Automotive & Transportation: exhaust systems, brake components, stainless chassis hardware.
- Construction & Infrastructure: structural connections in coastal or high-humidity environments.
- Electrical & Instrumentation: panel boards, cable trays, precision instrument mounting.
- Agriculture & Irrigation: spray systems, pumps, valve assemblies in moist environments.
Frequently Asked Questions
What is ASTM F594?
What do F594A, F594C, F594G etc. mean?
What is the difference between ASTM F594 and ASTM A194?
What certifications does Jade Alloys supply with F594 nuts?
What sizes of F594 nuts do you stock?
Can I get a same-day quotation?
Do you offer custom coatings on F594 nuts?
ASTM F594 Nuts Price in India
Indicative prices below are in USD per piece for standard-stock items. Final pricing depends on alloy group, condition, size, quantity, coating, and certification requirements.
| Product Description | Approx. Price (USD per piece) |
|---|---|
| ASTM F594 Stainless Steel 304 / 316 Hex Nut | US$ 0.01 - 0.05 |
| ASTM F594 All-Size Hexagon Thin Nuts | US$ 0.10 - 0.30 |
| ASTM F594 A2-70 Square Nut DIN 557 | US$ 0.10 - 0.30 |
| ASTM F594 Hex Nut (heavy fastener grade) | US$ 1.50 - 2.00 |
| ASTM F594 SS 304 18-8 A2-70 UNC Hex Nut (left thread) | US$ 0.05 - 0.10 |
| ASTM F594 Lock Nut | US$ 1.50 - 2.00 |
| ASTM F594 Hex Flange Weld Nut | US$ 0.10 - 1.20 |
| ASTM F594 Hexagon Nut (standard) | US$ 0.15 - 0.50 |
| ASTM F594 High Tensile Coupling Nut | US$ 0.01 - 0.10 |
Note: Prices are approximate and subject to market conditions. Contact sales@jadealloys.com for a firm price list with packing and freight.
Request a Quote - Get in Touch
Contact Jade Alloys for the best quote on ASTM F594 Stainless Steel Nuts. We offer:
- Same-day quotation for standard sizes
- Ex-stock availability in most popular grades
- EN 10204 Type 3.1 MTC with every shipment
- Worldwide export with full customs documentation
- Free technical support from our Mumbai-based engineering team
Phone: +91 9987685906 Email: sales@jadealloys.com Contact Us: Request a Quote
