ASTM A194 Gr 4 Nuts Supplier
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Manufacturing Range and Quality Certification
Every batch of A194 Gr 4 nuts moves through cold drawing or centerless grinding before dispatch, with no grade substitutions permitted at any stage.
- We cover manufacturing, trading, stocking, supply and export for A194 Gr. 4 Nuts across carbon, alloy, martensitic, and austenitic steel.
- Each batch passes through cold drawing or centerless grinding to meet ASTM A194 tolerances.
- ASTM A194 compliance leaves no room for grade substitutions during production.
- ISO 9001:2015 certification governs the quality management system across every production stage.
Applications of ASTM A194 Gr 4 Nuts
Pressure vessels, flanges, fittings, and valves rely on ASTM A194 Gr 4 nuts as the bolting material for joints that see elevated pressure and temperature simultaneously.
Stainless steel flange nuts under this specification attach directly to pipelines carrying corrosive media, where standard carbon steel fasteners degrade faster. The resistance matters most in wet or chemical-heavy lines. Refineries and petrochemical units select this grade specifically where bolted joints face both sustained heat and chemical exposure at the same time, a combination that pushes standard fasteners toward premature failure.
We, at Ratna Exports, encourage excellence and novelty in our products and direct them into them through continuous efforts and quality control. We strive to provide our consumers with the highest quality product profile, so they can choose the right one for their business. We are an ISO 9001: 2015 company, committed to establishing and maintaining consumer-oriented business practices.
Manufacturer, trader, stockist, supplier, and exporter of A194 Gr. 4 Nuts that are permanently or temporarily fastened through clamping.
For pressure vessels, flanges, fittings and valves that operate at elevated pressures and temperatures, our ASTM A194 Gr. 4 Nuts are an essential component of the bolting material. Stainless Steel A194 Gr. 5 Flange Nuts attach corrosive media conveying pipelines. Carbon, Alloy, Martensitic, and Austenitic materials are covered by Stainless Steel A194 Gr. 4 Nuts.
A reliable collection of quality products has been built over the last 25 years. New, sustainable, and cost-effective products are continually developed in response to industry trends and demands.
You can choose from carbon, alloys, or martensitic stainless steel nuts in ASTM A194 specifications ranging in size from 1 1/4″ to 4 ” and from metric M6 to M100. As part of ASTM A194, austenitic stainless steel nuts are also covered in sizes ranging from 1 1/4″ to M6. The nuts are designed for high-pressure and high-temperature service, and grade substitutions are not permitted. Cold drawing or centerless grinding are two methods of further processing the material.
For high-temperature applications, ASTM A194 Grade 4 specifies an alloy steel molybdenum-chromium hexagon nut for use with Bolts or Stud Bolts ASTM A194 Grade B16. It is compatible with ASTM A194 Grade B4 bolts, providing high temperatures and corrosion resistance. It is occasionally determined to be the best stainless steel for high-pressure and high-temperature applications. Heat-treated and annealed at a minimum temperature of 1,050°F (565°C).
In contrast to standard hex nuts, ASTM A194 grade 4 heavy hex nuts are larger and thicker. They are designed to handle high-pressure and temperature applications on alloys, carbon steels, and stainless steels. The ASTM A194 Grade 4 Nuts have lower properties and yield strength as a result of absorption of heat at high temperatures. They are resistant to scaling at temperatures above 500°C. They are mechanical fasteners with threaded holes. To secure several parts together, it is always used in conjunction with a mating bolt that serves as a clamping force and stops axial movement.
The A194 gr 4 Square Nut is a four-sided nut with a greater surface in contact with the part it is fastened to, so it offers considerable resistance to loosening. It is intended for use at high temperatures. Because it provides good strength at this temperature and is especially resistant to short- and long-term exposure to combustion products and hot gases at temperatures higher than 500°C. A solid solution reinforced alloy steel, SA 194 gr 4 Finished Hex Nuts can be used over a certain temperature range. Because of this, its strength can usually be hardened by heat treatment, precipitation, and solid solution. In applications where increasing resistance temperature is critical, it combines a variety of alloying components for the purpose of attaining the desired properties.

Contact Ratna Exports today for a best offer & competitive quotation Of ASTM A194 Grade 4 Nuts
Sizes and Material Grades
ASTM A194 Grade 4 covers an alloy steel molybdenum-chromium hexagon nut for Grade B16 stud bolts, compatible with Grade B4 bolting, heat-treated and annealed at 1,050°F (565°C) minimum.
Heavy Hex Nuts
ASTM A194 Grade 4 heavy hex nuts run larger and thicker than standard hex nuts, built for alloy, carbon, and stainless steel bolting under high pressure. Heat exposure lowers their yield strength, though they resist scaling above 500°C.
Square Nuts
A194 Gr 4 square nuts carry a four-sided profile with a wider contact surface against the fastened part, which raises resistance to loosening under vibration. They withstand short and long-term exposure to combustion products and hot gases above 500°C.
Finished Hex Nuts
SA 194 Gr 4 finished hex nuts use a solid solution reinforced alloy steel that holds strength across a defined temperature range. Heat treatment, precipitation and solid solution processing combine to harden the material for temperature-critical bolting.
Contact Ratna Exports for a quote on A194 Gr 4 nuts in your required size and material grade.
Technical Specifications of A194 Gr 4 Nuts
Selecting the right size starts with matching the thread to the mating bolt. Carbon, alloy, and martensitic stainless steel nuts span 1 1/4″ to 4″, or M6 to M100 in metric threading, under the ASTM A194 specification.
Austenitic stainless steel nuts follow the same standard across a size range from 1 1/4″ to M6. Buyers match material and size to the mating bolt grade and service environment, since the specification excludes grade substitutions entirely.
ASTM A194 Grade 4 Nuts Specifications
| A194 gr 4 Nut Size Metric |
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| ASTM A194 Grade 4 Hex Nut Size Inch |
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| Direction of Thread | Right hand |
| ASTM A194 Grade 4 Nuts Sizes | M24-M100 |
| Height of ASTM A194 Grade 4 Nuts |
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| Standard | Manufacturer of ASTM A194 Grade 4 Nuts as per DIN, PN, BS, UNI, ANSI, ISO, ASME, ASTM, IS, GB, CSN, EU, JIS, IFI, and all International Standards
|
| ASTM A194 Grade 4 Nuts Length | 3 mm to 200 mm |
| Surface Finish & Coating of ASTM A194 Grade 4 Nuts | Hot Dip Galvanised (HDG), Stainless Steel Passivated, black oxide, Dacroment, Nickel plated, Zinc, Sherardized, Bright Zinc Plated (BZP), Anodizing, Self-Colour, Plated zinc-nickel, Geometry |
| SA 194 gr 4 Nuts types | Flange Lock Nut, Flex Lock Nut, Dome Head Nuts, Hex Rivet Nuts, Captive Nuts, Half Nuts, K Lock Nut, Lock Nut, Dowel Nuts, Square Nut, Hex Nuts, Nylon Insert Nut, T Nuts, Cap Nut, Insert Nuts, Jam Nut, U Nuts, Cage Nuts, Flange Nuts, Heavy Hex Nuts, Wheel Nuts, Weld Nuts, Coupler Nuts, Rivet Nuts, Self Locking Nuts, Lug Nuts, Hex Weld Nuts, Eye Nuts, Nuts, Wing Nut, Dome Nuts, Custom Nuts Castle Nut, High Tensile Heavy Hex Nuts, 2 Way Lock Nut, High Crown Acorn Nuts, Slotted Nut |
| Port of Dispatch | Mumbai or Kalamboli ports in Maharashtra state of India |
| Why Jignesh Steel? |
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| Material Origin | ASTM A194 Grade 4 Nuts are Western European. Eastern origin is possible on request. |
| MOQ | 5 pieces |
| Preferred ASTM A194 Grade 4 Nut Drawing Formats | JPEG, PDF, CAD, STP, IGS |
| Free Samples | Yes |
| Payment Terms | T/T, Western Union, Paypal, L/C or Trade Assurance 30% deposit & balance before shipping |
| Find our dealers & distributors of ASTM A194 Grade 4 Nuts | Manama, Sharjah, Chennai, Abu Dhabi, Muscat, Vadodara, Karachi, Navi Mumbai, Dubai, Jamshedpur, Perth, Ranchi, Hyderabad, Shah Alam, Ludhiana, Tehran, Gurgaon, Thiruvananthapuram, Seoul, Nagpur, Tau, India, Dhaka, Dammam, Lagos, Kuala Lumpur, Panipat, Istanbul, Ankara, Gimhae-si, Noida, Sydney, Mexico, Montreal, New Delhi, Ahvaz, Jaipur, Pune, Howrah, Patna, Rajkot, Bhubaneswar, Caracas, Kuwait, Vung Granada, Nashik, Janeiro, Houston, Surat, Calgary, Bengaluru, Port-of-Spain, Riyadh, Doha, Mumbai, Courbevoie, Gujarat, Melbourne, Coimbatore, Jakarta, Ahmedabad, Agra, Singapore, London, Bangalore, Mysuru, Lucknow, Indore, Pimpri-Chinchwad, Kochi, Brisbane, Ernakulam, Baroda, Kolkata, Santiago, Kanpur, Thane, Khobar, Vapi, Bogota |
| A194 Grade 4 Nuts Application and Uses | Industrial, Petrochemical, Railway, Nuclear plants, Construction, Electronic, Wind tower, and Automotive industry |
| Delivery time | Regular product is about 7-15 days |
| Ask for Test Certificates from ASTM A194 Grade 4 Nuts manufacturers |
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| ISO – International Organization for Standardization |
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types of ASTM A194 Gr 4 Nuts

ASTM A194 Grade 4 Lock Nut
ASTM A194 Grade 4 Slotted flange nuts

ASTM A194 Grade 4 Heavy Hex Nut

ASTM A194 Grade 4 Hex Nut
Chemical Composition Of ASTM A194 Grade 4 Nuts
Element | Ferritic Steel |
AISI 501 Stainless Steel ASTM A194 Grade 4 | |
CompositionA, % | |
C | 0.4-0.5 |
Mn | 0.7-0.9 |
Phosphorus | 0.035 |
S | 0.040 |
Si | 0.15-0.35 |
Cr | – |
Molybdenum | 0.20-0.30 |
Mechanical Properties Of ASTM A194 Grade 4 Nuts
| ASTM | Completed Nuts | Sample Nut After Heat Treatment | |||
| Brinell Hardness, BHN | Rockwell Hardness | Brinell Hardness, BHN, min | Rockwell Hardness, HRB, min | ||
| HRC | HRB | ||||
| A194 Grade 3 | 248 – 327 | 24 – 35 | … | 201 | 94 |
Looking to buy ASTM A194 Gr 4 Nuts From a manufacturer in India
ASTM A194 Grade 4 Nuts Equivalent Grade
| ASTM | ASME | Grade | UNS | DIN | WNR. |
| ASTM A194 Grade 4 | SA 194 Grade 4 | 501 Stainless Steel | S50100 | 12CrMo19-5 | 1.7362 |
ASTM A194 Grade 4 Nuts Weight
| Size | A194 gr 4 Finished Hex Nuts | AISI 501 SA 194 gr 4 Heavy Hex Nuts | A194 gr 4 Finished Jam Nuts | AISI 501 SA 194 gr 4 Heavy Hex Jam Nuts | A194 gr 4 Square Nuts | AISI 501 SA 194 gr 4 Heavy Square Nuts |
| 1/2″ | 3.750 | 6.540 | 2.620 | 4.000 | 5.780 | 7.870 |
| 5/8″ | 7.330 | 11.900 | 4.930 | 6.960 | 10.800 | 14.300 |
| 3/4″ | 11.900 | 19.300 | 7.700 | 11.000 | 15.400 | 23.500 |
| 7/8″ | 19.000 | 29.700 | 12.000 | 16.700 | 24.500 | 36.200 |
| 1″ | 28.300 | 42.500 | 17.600 | 23.500 | 36.300 | 51.500 |
| 1-1/8″ | 40.300 | 59.200 | 24.700 | 32.400 | 52.500 | 72.400 |
| 1-1/4″ | 54.300 | 78.600 | 36.100 | 45.800 | 70.600 | 95.500 |
| 1-3/8″ | 73.000 | 102.000 | 47.900 | 59.300 | 94.500 | 125.000 |
| 1-1/2″ | 94.300 | 131.000 | 60.900 | 74.800 | 122.000 | 161.000 |
| 1-5/8″ | 162.000 | 91.600 | ||||
| 1-3/4″ | 151.000 | 204.000 | 100.000 | 114.000 | ||
| 1-7/8″ | 241.000 | 134.000 | ||||
| 2″ | 224.000 | 299.000 | 140.000 | 165.000 | ||
| 2-1/4″ | 419.000 | 227.000 | ||||
| 2-1/2″ | 564.000 | 332.000 | ||||
| 2-3/4″ | 738.000 | 429.000 | ||||
| 3″ | 950.000 | 545.000 | ||||
| 3-1/4″ | 1194.000 | 651.000 | ||||
| 3-1/2″ | 1526.000 | 851.000 | ||||
| 3-3/4″ | 1812.000 | 1005.000 | ||||
| 4″ | 2180.000 | 1200.000 |
ASTM A194 Grade 4 Nuts Dimensions Chart in mm
| A194 gr 4 Metric Nut Size | Thread Pitch | s | e | m | ||
| Width Across Flats | Width Across Corners | Height of the AISI 501 SA 194 gr 4 Nut | ||||
| max. | min. | min. | max. | min. | ||
| M1.6 | 0.35 | 3.20 | 3.02 | 3.41 | 1.30 | 1.05 |
| M2 | 0.4 | 4.00 | 3.82 | 4.32 | 1.60 | 1.35 |
| M2.5 | 0.45 | 5.00 | 4.82 | 5.45 | 2.00 | 1.75 |
| M3 | 0.5 | 5.50 | 5.32 | 6.01 | 2.40 | 2.15 |
| M3.5* | 0.6 | 6.00 | 5.82 | 6.58 | 2.80 | 2.55 |
| M4 | 0.7 | 7.00 | 6.78 | 7.66 | 3.2 | 2.9 |
| M5 | 0.8 | 8.00 | 7.78 | 8.79 | 4.7 | 4.4 |
| M6 | 1 | 10.00 | 9.78 | 11.05 | 5.2 | 4.9 |
| M8 | 1.25 | 13.00 | 12.73 | 14.38 | 6.80 | 6.44 |
| M10 | 1.5 | 16.00 | 15.73 | 17.77 | 8.40 | 8.04 |
| M12 | 1.75 | 18.00 | 17.73 | 20.03 | 10.80 | 10.37 |
| M14* | 2 | 21.00 | 20.67 | 23.36 | 12.8 | 12.1 |
| M16 | 2 | 24.00 | 23.67 | 26.75 | 14.8 | 14.1 |
| M18* | 2.5 | 27.00 | 26.16 | 29.56 | 15.8 | 15.1 |
| M20 | 2.5 | 30.00 | 29.16 | 32.95 | 18.0 | 16.9 |
| M22* | 2.5 | 34 | 33 | 37.29 | 19.4 | 18.1 |
| M24 | 3 | 36 | 35 | 39.55 | 21.5 | 20.2 |
| M27* | 3 | 41 | 40 | 45.2 | 23.8 | 22.5 |
| M30 | 3.5 | 46 | 45 | 50.85 | 25.6 | 24.3 |
| M33* | 3.5 | 50 | 49 | 55.37 | 28.7 | 27.4 |
| M36 | 4 | 55.0 | 53.8 | 60.79 | 31.0 | 29.4 |
| M39* | 4 | 60.0 | 58.8 | 66.44 | 33.4 | 31.8 |
| M42 | 4.5 | 65.0 | 63.1 | 71.3 | 34.0 | 32.4 |
| M45* | 4.5 | 70.0 | 68.1 | 76.95 | 36.0 | 34.4 |
| M48 | 5 | 75.0 | 73.1 | 82.6 | 38.0 | 36.4 |
| M52* | 5 | 80.0 | 78.1 | 88.25 | 42.0 | 40.4 |
| M56 | 5.5 | 85.0 | 82.8 | 93.56 | 45.0 | 43.4 |
| M60* | 5.5 | 90.0 | 87.8 | 99.21 | 48.0 | 46.4 |
| M64 | 6 | 95.0 | 92.8 | 104.86 | 51.0 | 49.1 |
ASTM A194 Grade 4 Nuts Certificates
Ratna Exports provides Manufacturer TCs (Test Certificates) that comply with EN 10204/3.1B, Raw Materials Certificates, Radiography Test Reports, and Third Party Inspection Reports. Aside from standard certificates, we also provide NACE MR 01075. FERRITE CONTENT as per norms if clients request it.
- EN 10204/3.1B,
- Raw Materials Certificate
- 100% Radiography Test Report
- Third-Party Inspection Report, etc
ASTM A194 Grade 4 Nuts Value Added Services
Material Testing:
We at RatnaExports.com ensure that all our materials go through strict quality tests before dispatching them to our clients.
Tensile testing of areas is an example of mechanical testing
Test of hardness
Analysis of Chemical Compounds by Spectroscopy
Testing for Positive Material Identification (PMI)
The flattening test
Testing on a micro and macro scale
Testing for Pitting Resistance
Test for flares
Test for intergranular corrosion (IGC)
Documentation
HS Code is included on commercial invoices
Including net weight and gross weight, number of boxes, marks, and numbers
Embassy or Chamber of Commerce legalization/attestation of the Certificate of Origin
Obtaining a Fumigation Certificate
Test reports for raw materials
Traceability records for materials
Plan for Quality Assurance (QAP)
Charts for heat treatment
Certificates certifying NACE MR0103 and NACE MR0175
Certificates of Material Test (MTC) in accordance with EN 10204 3.1 and EN 10204 3.2
A letter of guarantee
Laboratory Test Reports Approved by NABL
Specifications/qualifications for welding procedures, WPS/PQR
For the purposes of the Generalized System of Preferences (GSP), fill out Form A
ASTM A194 Grade 4 Nuts Packaging
A wide range of industries utilizes ASTM A194 Grade 4 Nuts, including petrochemicals, oil, and gas, power generation, bulk liquid transportation, chemicals, pharmaceuticals, pulp and paper manufacturing, textiles, etc. In accordance with international standards, we manufacture all our ASTM A194 Grade 4 Nuts, packaged in wooden cases so that there is no damage during transportation. For exports, standard export packaging is done in wooden cases. The ASTM A194 Grade 4 Nuts we offer are marked with grades, lot numbers, sizes, degrees, and our trademark. On special request, ASTM A194 Grade 4 Nuts can also carry custom markings.
Frequently Asked Questions
ASTM A194 Gr 4 nuts are molybdenum-chromium alloy steel hexagon nuts built for bolting in high-pressure, high-temperature service across pressure vessels, flanges, and valve assemblies.
Refineries, petrochemical plants, power generation facilities, and pipeline networks use these nuts wherever bolted joints face sustained heat above 500°C and corrosive process media.
Key features include heat treatment and annealing at a minimum of 1,050°F, resistance to scaling above 500°C, and compatibility with Grade B4 and B16 stud bolts.
Carbon, alloy, and martensitic stainless steel nuts span 1 1/4″ to 4″, or M6 to M100 in metric sizing; austenitic variants follow sizes from 1 1/4″ to M6.
Match the nut grade to your mating bolt, confirm service temperature and pressure ratings, and consult Ratna Exports for material certification before ordering.
Applications Industry ASTM A194 Grade 4 Nuts
- Pharmaceutical Industry
- Oil Refineries
- Textile Industries
- Nuclear Plants
- Chemical Industries
- Power Plant
- Petrochemicals Industry
- Sugar Industry
- Engineering Industry
- Chemical Industry
- Food Industry
- Marine Industry

