ASTM A193 & A194 Certified | ISO 9001:2015 Approved | 1000°C+ Oxidation Resistance | M3–M56 In Stock
Ordinary fasteners fail at temperature. When the equipment is operating at temperatures above 1000°C, it oxidizes, scales, and fails to grip in the most critical moments. Unifit Fastener was designed to fill just that void. With excellent resistance to oxidation, carburization, and thermal fatigue properties compared with SS 304 or 316 (max continuous service ~870°C), SS 310/310S serve up to ~1150°C, our 310 SS bolts are the preferred choice for heat exchangers, furnace components, boiler assemblies, kilns, and petrochemical reactors in the international and Indian markets. Each batch we ship is chemically tested, dimensionally verified, and has consistent tensile strength, elongation, and hardness, not just the sample. From M3 to M56 hex bolts, heavy hex bolts, studs, and U-bolts to custom fasteners, M3 to M56 hex bolts are a product that Unifit Fastener offers from the factory with engineering-grade quality assurance and offers speedy pan-India and export dispatch in small or bulk quantities.
Unifit Fastener is a manufacturer and exporter of SS 310 and 310S hex bolts, studs, U-bolts, and heavy hex fasteners that are engineered for extreme temperature, corrosive atmosphere, and critical industrial service requirements and trusted by EPC contractors, OEMs, and process plants in 40+ countries.
Get a Free Quote in 24 HoursStainless steel 310 and 310S are austenitic chromium-nickel alloys purpose-built for continuous high-temperature service. Grade 310 (UNS S31000 / Werkstoff 1.4841) offers higher carbon content and greater strength at elevated temperatures, while 310S (UNS S31008 / Werkstoff 1.4845) is the low-carbon variant, chosen where weldability and resistance to inter-granular corrosion after welding are priorities. Both grades retain excellent mechanical integrity from cryogenic conditions up to roughly 1150°C, making Unifit Fastener's 310/310S bolt range suitable for the most demanding thermal environments in India and abroad.
| Specification | Details |
|---|---|
| Material Standard | ASTM A193, ASTM A194, ASME SA193, ASME SA194 |
| Manufacturing Standards | ASTM, ASME, DIN, BS, ISO, EN & other international specifications |
| Bolt & Screw Diameter | M3 to M56 (3/16" to 2") |
| Nut Diameter | M3 to M56 (3/16" to 2") |
| Washer Size Range | M3 to M56 (3/16" to 2") |
| Machine Screw Diameter | M1.6 to M12 |
| Available Length | 3 mm to 200 mm (Custom lengths available on request) |
| Grade | C | Mn | Si | P | S | Cr | Ni | N |
|---|---|---|---|---|---|---|---|---|
| SS 310 (min/max) | 0.08–0.25max | 2.0 max | 1.50 max | 0.045 max | 0.030 max | 24.0–26.0 | 19.0–22.0 | – |
| SS 310S (min/max) | 0.08 max | 2.0 max | 1.00 max | 0.045 max | 0.030 max | 24.0–26.0 | 19.0–21.0 | – |
| Grade | Tensile Strength (MPa min) | Yield Strength 0.2% (MPa min) | Elongation (% in 50mm min) | Hardness (HRB max) |
|---|---|---|---|---|
| SS 310 | 515 | 205 | 40 | 95 |
| SS 310S | 515 | 205 | 40 | 95 |
| Property | Value |
|---|---|
| Density | 7.9–8.0 g/cm³ |
| Melting Point | 1402–1450°C |
| Max Continuous Service Temperature | Up to 1150°C (oxidizing atmosphere) |
| Elastic Modulus | ~193 GPa |
| Electrical Resistivity | ~720 n·Ω·m |
| Parameter | Range |
|---|---|
| Applicable Specification | ASTM A193 / A194, ASME SA193 / SA194 |
| Size Range | M3 – M56 (3/16" – 2") |
| Length Range | 3 mm – 200 mm (custom lengths available) |
| Standards Followed | DIN, BS, ASTM, JIS, GOST, AFNOR, EN |
| Grade | UNS No. | Werkstoff Nr. | JIS | BS | GOST | EN |
|---|---|---|---|---|---|---|
| SS 310 | S31000 | 1.4841 | SUS 310 | 310S24 | 20Ch25N20S2 | X15CrNi25-20 |
| SS 310S | S31008 | 1.4845 | SUS 310S | 310S16 | 20Ch23N18 | X8CrNi25-21 |
Thanks to their exceptional heat and oxidation resistance, Unifit Fastener's SS 310/310S bolts are specified across:
| Property | SS 310 | SS 310S | SS 304 | SS 316 |
|---|---|---|---|---|
| Cr / Ni Content | 24–26% / 19–22% | 24–26% / 19–21% | 18–20% / 8–10.5% | 16–18% / 10–14% |
| Carbon Content | 0.08–0.25% | 0.08% max | 0.08% max | 0.08% max |
| Max Service Temp. | ~1150°C | ~1150°C | ~870°C | ~870°C |
| Best Suited For | Extreme heat, furnaces, kilns | Heat + post-weld corrosion resistance | General purpose corrosion resistance | Marine & chloride environments |
| Relative Cost | High | High | Moderate | Moderate-High |
Every Unifit Fastener SS 310/310S bolt passes through a controlled, documented production flow:
We offer wide range of industrial Stainless Steel 310, 310S Bolts that in compliance with IS, BS and DIN standards at best market prices in India. To know more about the latest price of Stainless Steel 310/310S Bolts Please Call 91 22 66518521 or Send an Email to chirag@unifitmetalloys.com
Stainless Steel 310/310S Bolts Sizes |
|||
| Stainless Steel 310/310S Bolts Sizes | Stainless Steel 310/310S Bolts size chart | Stainless Steel 310/310S Bolts size guide | Stainless Steel 310/310S Bolts dimensions |
| 3/8″-16 x 1″ Grade 5 Finish Stainless Steel 310/310S Bolts | 1/2″-13 x 1-1/2″ Grade 5 Finish Stainless Steel 310/310S Bolts | 1/4″-20 x 1″ Grade 5 Finish Stainless Steel 310/310S Bolts | |
| 3/8″-16 x 1-1/4″ Grade 5 Finish Stainless Steel 310/310S Bolts | 3/8″-16 x 1-1/2″ Grade 5 Finish Stainless Steel 310/310S Bolts | 1/4″-20 x 3/4″ Grade 5 Finish Stainless Steel 310/310S Bolts | |
| 1/2″-13 x 2″ Grade 8 Yellow Finish Stainless Steel 310/310S Bolts | 1/2″-13 x 2″ Grade 5 Finish Stainless Steel 310/310S Bolts | 1/2″-13 x 1-1/2″ Grade 8 Yellow Finish Stainless Steel 310/310S Bolts | |
| 5/8″-11 x 2″ Grade 8 Yellow Finish Stainless Steel 310/310S Bolts | 1/4″-20 x 3/4″ Grade 18-8 Stainless Steel Stainless Steel 310/310S Bolts | 5/16″-18 x 1″ Grade 5 Finish Stainless Steel 310/310S Bolts | |
| 3/8″-16 x 1″ Grade 8 Yellow Finish Stainless Steel 310/310S Bolts | 3/8″-16 x 1″ Grade 18-8 Stainless Steel Stainless Steel 310/310S Bolts | 3/8″-16 x 1-1/2″ Grade 8 Yellow Finish Stainless Steel 310/310S Bolts | |
| 1/4″-20 x 1″ Grade 18-8 Stainless Steel Stainless Steel 310/310S Bolts | 5/8″-11 x 2″ Grade 5 Finish Stainless Steel 310/310S Bolts | 5/8″-11 x 2-1/2″ Grade 8 Yellow Finish Stainless Steel 310/310S Bolts | |
| 3/8″-16 x 2″ Grade 5 Finish Stainless Steel 310/310S Bolts | 3/8″-16 x 1-1/4″ Grade 8 Yellow Finish Stainless Steel 310/S Bolts | ||
| MM THREADS AS PER IS 1363/67 | ||||||||||
| APPROXIMATE WEIGHT IN KGS FOR 100 NOS | ||||||||||
| LENGTH | DIAMETER | |||||||||
| M 5 | M 6 | M 8 | M 10 | M 12 | M 14 | M 16 | M 18 | M 20 | M 22 | |
| 16 mm | 0.448 | 0.743 | 1.590 | 3.211 | ||||||
| 20 mm | 0.598 | 0.812 | 1.711 | 3.411 | 4.892 | |||||
| 25 mm | 0.660 | 0.897 | 1.871 | 3.660 | 5.252 | 8.170 | ||||
| 30 mm | 0.737 | 1.010 | 2.070 | 3.912 | 5.574 | 9.690 | 10.707 | 18.657 | ||
| 35 mm | 0.804 | 1.120 | 2.271 | 4.223 | 5.974 | 10.000 | 11.416 | 16.026 | 19.608 | |
| 40 mm | 0.881 | 1.230 | 2.470 | 4.533 | 6.410 | 10.288 | 12.107 | 16.667 | 20.747 | |
| 45 mm | 0.958 | 1.340 | 2.671 | 4.840 | 6.859 | 10.504 | 12.821 | 17.241 | 21.739 | |
| 50 mm | 1.030 | 1.450 | 2.870 | 5.155 | 7.299 | 11.261 | 13.624 | 17.857 | 22.727 | 28.409 |
| 55 mm | 1.560 | 3.071 | 5.464 | 7.740 | 11.628 | 14.409 | 18.868 | 23.810 | 30.120 | |
| 60 mm | 1.670 | 3.270 | 5.774 | 8.183 | 12.255 | 15.244 | 20.000 | 25.126 | 32.051 | |
| 65 mm | 1.781 | 3.472 | 6.083 | 8.621 | 12.626 | 16.026 | 21.008 | 26.455 | 34.014 | |
| 70 mm | 1.890 | 3.671 | 6.394 | 9.058 | 12.987 | 16.835 | 22.124 | 27.778 | 35.461 | |
| 75 mm | 2.000 | 3.873 | 6.702 | 9.506 | 13.228 | 17.606 | 23.256 | 29.070 | 39.063 | |
| 80 mm | 2.111 | 4.072 | 7.013 | 10.000 | 13.889 | 18.248 | 24.510 | 30.303 | 40.000 | |
| 90 mm | 4.472 | 7.634 | 10.917 | 14.925 | 19.841 | 26.042 | 33.113 | 41.667 | ||
| 100 mm | 4.873 | 8.251 | 11.820 | 16.340 | 21.459 | 27.778 | 35.714 | 46.296 | ||
| 110 mm | 8.881 | 12.723 | 17.730 | 23.041 | 31.250 | 38.168 | 47.170 | |||
| 120 mm | 9.506 | 13.624 | 18.797 | 24.631 | 32.895 | 40.984 | 50.000 | |||
| 130 mm | 10.101 | 14.535 | 20.000 | 26.316 | 34.722 | 43.478 | 52.632 | |||
| 140 mm | 10.707 | 15.432 | 20.833 | 27.933 | 35.461 | 46.296 | 55.556 | |||
| 150 mm | 11.312 | 16.340 | 22.222 | 29.412 | 37.594 | 48.544 | 58.824 | |||
| 160 mm | 11.905 | 17.241 | 24.272 | 31.056 | 40.984 | 50.505 | 61.728 | |||
| 170 mm | 12.500 | 18.116 | 32.680 | 53.191 | 64.935 | |||||
| 180 mm | 13.123 | 19.011 | 26.882 | 34.247 | 55.556 | 67.568 | ||||
| 190 mm | 13.736 | 19.920 | 35.971 | 58.140 | 70.423 | |||||
| 200 mm | 14.327 | 20.833 | 29.586 | 37.594 | 49.020 | 60.976 | 73.529 | |||
| 220 mm | 15.528 | 22.624 | 40.650 | 65.789 | 79.365 | |||||
| 240 mm | 16.722 | 24.510 | 43.860 | 71.429 | 84.746 | |||||
| 250 mm | 17.301 | 25.381 | 45.455 | 74.627 | 87.719 | |||||
| 260 mm | 17.921 | 26.316 | 47.170 | 76.923 | 90.909 | |||||
| 280 mm | 19.157 | 28.090 | 50.505 | 81.967 | 98.039 | |||||
| 300 mm | 20.325 | 29.940 | 53.763 | 87.719 | 104.167 | |||||
| 320 mm | 31.646 | 56.818 | 92.593 | |||||||
| 340 mm | 33.557 | 60.241 | 98.039 | |||||||
| 360 mm | 35.211 | 63.291 | 104.167 | |||||||
| 380 mm | 37.037 | 66.667 | 108.696 | |||||||
| 400 mm | 39.063 | 69.444 | 113.636 | |||||||
Unifit Fastener manufactures, suppliers and exports of Stainless Steel 310/310S Bolts to various countries such as United Arab Emirates, South Korea, Chile, Brazil, Austria, Thailand, Bhutan, Bolivia, Mexico, Denmark, Iran, Iran, Kazakhstan, Italy, Mexico, Colombia, Sri Lanka, Chile, China, Oman, Singapore, Kenya, Estonia, New Zealand, Costa Rica, South Africa, Poland, Lithuania, United States, Vietnam, Lebanon, Finland, Afghanistan, Algeria, Kuwait, Peru, Nigeria, Gabon, Norway, Ukraine, Australia, Canada, Serbia, Angola, Egypt, United Kingdom, Malaysia, Trinidad & Tobago, Jordan, Libya, France, Turkey, Belgium, Slovakia, Ecuador, Indonesia, Qatar, Belarus, Venezuela, Nigeria, Philippines, Romania, Argentina, Israel, Tunisia, Bulgaria, Czech Republic, Hong Kong, Taiwan, Iraq, Spain, Poland, Netherlands, Pakistan, Japan, Yemen, Portugal, Hungary, Mongolia, Sweden, Morocco, Bangladesh, Azerbaijan, Saudi Arabia, Bahrain, Switzerland, Croatia, Ghana, Greece, Russia.
SS 310 has a higher carbon content (0.08–0.25%) giving it greater high-temperature strength, while SS 310S is the low-carbon variant (0.08% max carbon) chosen for better weldability and reduced risk of carbide precipitation after welding.
Both grades can operate continuously in oxidizing atmospheres up to approximately 1150°C, which is why they are widely used in furnace, kiln, and heat-exchanger applications.
We stock and manufacture sizes from M3 to M56 (3/16" to 2") with lengths from 3mm to 200mm, plus custom sizes on request.
Our bolts are manufactured to ASTM A193/A194 and ASME SA193/SA194, and can also be supplied to DIN, BS, JIS, GOST, AFNOR and EN standards on request.
Yes, every order is accompanied by chemical and mechanical test certificates (EN 10204 3.1) for full traceability.
Yes, we manufacture bolts, studs, U-bolts and nuts to custom drawings, non-standard lengths, and special thread requirements.