ASTM A193 / A194 certified SS 317 & 317L bolts, nuts, studs & washers — UNS S31700 / S31703, sizes M2 to M56, manufactured and exported worldwide by Unifit Fastener.
In environments where it's necessary to resist sulfuric acid, chloride wash-down, or hot process streams, regular 304 or even 316 hardware may fall short, and that is when stainless steel 317 / 317L bolts come into the rescue. Our 317 and 317L bolts are manufactured to ASTM A193, A194, and ASME SA-193 / SA-194 with a higher loading of molybdenum and chromium (around 3-4%) as compared to 316L and 316, which results in superior resistance to pitting and crevice corrosion in aggressive service with high levels of chlorine. The low-carbon 317L variant (UNS S31703) has excellent resistance to intergranular attack after welding, making it a popular choice for fabricated assemblies in chemical, petrochemical, and pulp-and-paper plants. All are dual certified, batch traceable, and covered by an EN 10204 3.1 mill test report and come in a variety of sizes from M2 to M56 hex bolts and socket cap bolts to U-bolts and eye bolts and their matching nuts and washers. From a wide range of ready stock to custom sizing, Unifit Fastener is helping engineers to confidently specify and have the correct corrosion-grade fastener for the job, on time, with a same-day quote.
Request a QuoteUnifit Fastener manufactures a complete 317 / 317L bolting range so buyers can source every component of a joint from one certified supplier:
| Product Category | Common Types Offered |
|---|---|
| Bolts | Hex bolts, heavy hex bolts, carriage bolts, U-bolts, eye bolts, stove bolts, plow bolts |
| Screws | Socket / Allen cap screws, machine screws, countersunk slotted screws, grub screws |
| Stud Bolts | Full-thread studs, tap-end studs, threaded rod (ASTM A193) |
| Nuts | Hex nuts, heavy hex nuts, jam nuts, nylock nuts (ASTM A194) |
| Washers | Flat, spring, structural washers (USS & SAE) |
| Parameter | Details |
|---|---|
| Standards | ASTM A193 / A194, ASME SA-193 / SA-194 |
| Specifications followed | IS, BS, DIN, ISO, ASTM |
| Size range | M2 to M56 (3/16" to 2") |
| Length | 3 mm to 200 mm (custom on request) |
| Dimension standards | DIN 931 / 933 / 934 / 976, ISO 4014 / 4017, ASME B18.2.1 |
| Thread type | Metric coarse/fine, UNC, UNF, BSW, BSF |
| Forms | Hex, square, round, threaded — as per gauge |
| Grade | C | Mn | Si | P | S | Cr | Mo | Ni |
|---|---|---|---|---|---|---|---|---|
| 317 | 0.08 max | 2.00 max | 1.00 max | 0.045 max | 0.030 max | 18.0–20.0 | 3.0–4.0 | 11.0–14.0 |
| 317L | 0.03 max | 2.00 max | 1.00 max | 0.045 max | 0.030 max | 18.0–20.0 | 3.0–4.0 | 11.0–15.0 |
| Grade | Tensile (MPa min) | Yield 0.2% (MPa min) | Elongation (% min) | Hardness (HRB max) | Brinell (HB max) |
|---|---|---|---|---|---|
| 317 | 620 | 275 | 35 | 85 | 217 |
| 317L | 515 | 205 | 40 | 85 | 217 |
Note: Actual mechanical values are governed by the applicable ASTM/ASME class (e.g. B8M / B8MLN) and product diameter; certified values are stated on each mill test report.
| Grade | ASTM | UNS | EN / DIN Numeric | JIS | SS Notation |
|---|---|---|---|---|---|
| 317 | A193 | S31700 | 1.4449 | SUS 317 | SS 317 |
| 317L | A193 | S31703 | 1.4438 | SUS 317L | SS 317L |
| Nominal Size | Body Dia (max) | Head Thickness (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 |
| M36 | 36.00 | 23.38 | 55.00 | 63.51 |
The corrosion resistance of 317/317L bolting makes it a workhorse across process-intensive sectors:
| ASTM Standards | IS Standards | DIN Standards | ISO / ANSI / BS Standards |
|---|---|---|---|
| ASTM A193 Grade B8M Class 1 | IS 1363 | DIN 444 | ISO 4014 |
| ASTM A193 Grade B8M Class 2 | IS 1364 | DIN 580 | ISO 4017 |
| ASTM A193 | IS 1367 | DIN 931 | ISO 4762 |
| ASTM F593 Group 2 | IS 3757 | DIN 933 | ISO 7412 |
| ASTM F593 CW | IS 6639 | DIN 960 | ISO 8676 |
| ASTM A320 (where applicable) | DIN 961 | ANSI B18.2.1 | |
| ASTM F1554 (Anchor Bolts) | DIN 976 | ANSI B18.2.3 | |
| DIN 6921 | ANSI B18.3 | ||
| DIN 6922 | BS EN ISO 4014 | ||
| DIN 6914 | BS EN ISO 4017 | ||
| DIN 6915 | BS 3692 | ||
| DIN 7990 |
| Nominal Size | Thread Pitch | Available Lengths | Metric Equivalent |
|---|---|---|---|
| 1/4"-20 | UNC | 1/2" – 4" | M6 |
| 5/16"-18 | UNC | 1/2" – 6" | M8 |
| 3/8"-16 | UNC | 1" – 8" | M10 |
| 1/2"-13 | UNC | 1" – 10" | M12 |
| 5/8"-11 | UNC | 1-1/2" – 12" | M16 |
| 3/4"-10 | UNC | 2" – 12" | M20 |
| 7/8"-9 | UNC | 2" – 12" | M22 |
| 1"-8 | UNC | 2" – 16" | M24 |
| M6 | Metric Coarse | 12–100 mm | 1/4" |
| M8 | Metric Coarse | 16–120 mm | 5/16" |
| M10 | Metric Coarse | 20–150 mm | 3/8" |
| M12 | Metric Coarse | 25–200 mm | 1/2" |
| M16 | Metric Coarse | 30–250 mm | 5/8" |
| M20 | Metric Coarse | 40–300 mm | 3/4" |
| M24 | Metric Coarse | 50–300 mm | 1" |
| Length (mm) | M5 | M6 | M8 | M10 | M12 | M14 | M16 | M18 | M20 | M22 |
|---|---|---|---|---|---|---|---|---|---|---|
| 16 | 0.448 | 0.743 | 1.590 | 3.211 | – | – | – | – | – | – |
| 20 | 0.598 | 0.812 | 1.711 | 3.411 | 4.892 | – | – | – | – | – |
| 25 | 0.660 | 0.897 | 1.871 | 3.660 | 5.252 | 8.170 | – | – | – | – |
| 30 | 0.737 | 1.010 | 2.070 | 3.912 | 5.574 | 9.690 | 10.707 | – | 18.657 | – |
| 35 | 0.804 | 1.120 | 2.271 | 4.223 | 5.974 | 10.000 | 11.416 | 16.026 | 19.608 | – |
| 40 | 0.881 | 1.230 | 2.470 | 4.533 | 6.410 | 10.288 | 12.107 | 16.667 | 20.747 | – |
| 45 | 0.958 | 1.340 | 2.671 | 4.840 | 6.859 | 10.504 | 12.821 | 17.241 | 21.739 | – |
| 50 | 1.030 | 1.450 | 2.870 | 5.155 | 7.299 | 11.261 | 13.624 | 17.857 | 22.727 | 28.409 |
| 60 | – | 1.670 | 3.270 | 5.774 | 8.183 | 12.255 | 15.244 | 20.000 | 25.126 | 32.051 |
| 80 | – | 2.111 | 4.072 | 7.013 | 10.000 | 13.889 | 18.248 | 24.510 | 30.303 | 40.000 |
| 100 | – | – | 4.873 | 8.251 | 11.820 | 16.340 | 21.459 | 27.778 | 35.714 | 46.296 |
| 120 | – | – | – | 9.506 | 13.624 | 18.797 | 24.631 | 32.895 | 40.984 | 50.000 |
| 150 | – | – | – | 11.312 | 16.340 | 22.222 | 29.412 | 37.594 | 48.544 | 58.824 |
| 200 | – | – | – | 14.327 | 20.833 | 29.586 | 37.594 | 49.020 | 60.976 | 73.529 |
| 250 | – | – | – | 17.301 | 25.381 | – | 45.455 | – | 74.627 | 87.719 |
| 300 | – | – | – | 20.325 | 29.940 | – | 53.763 | – | 87.719 | 104.167 |
| 400 | – | – | – | – | 39.063 | – | 69.444 | – | 113.636 | – |
The price of Stainless Steel 317/317L Bolts depends on factors such as bolt size, length, thread type, quantity, surface finish, and order volume. A Unifit Fastener, we supply premium-quality SS 317 and SS 317L bolts manufactured in accordance with ASTM, DIN, ISO, and IS standards at competitive prices across India and international markets.
For the latest Stainless Steel 317/317L Bolts price list, bulk order discounts, or a customized quotation, please contact our sales team.
| Product | Price Availability |
|---|---|
| Stainless Steel 317 Bolts | Available on Request |
| Stainless Steel 317L Bolts | Available on Request |
| SS 317 Hex Bolts | Get Latest Price |
| SS 317L Hex Bolts | Get Latest Price |
| SS 317 Heavy Hex Bolts | Get Latest Price |
| SS 317/317L Stud Bolts | Get Latest Price |
| SS 317/317L Anchor Bolts | Get Latest Price |
| SS 317/317L U Bolts | Get Latest Price |
Phone: +91 22 66518521
Email: chirag@unifitmetalloys.com
Note: Prices are subject to change based on raw material costs, dimensions, quantity, specifications, and delivery location. Contact us for the most up-to-date pricing and availability.
| Property | SS 316L | SS 317 | SS 317L |
|---|---|---|---|
| Molybdenum (%) | 2.0–3.0 | 3.0–4.0 | 3.0–4.0 |
| Carbon (max %) | 0.03 | 0.08 | 0.03 |
| Pitting resistance | Good | Very good | Very good |
| Weld sensitisation | Low risk | Higher risk | Lowest risk |
| Best use | General marine | Non-welded acid service | Welded acid/chloride service |
Every Unifit Fastener 317/317L lot moves through a controlled workflow designed for traceability and repeatable quality:
Plain passivated, electro-polished, hot-dip galvanised, zinc, PTFE / Xylan, phosphate and mirror-buffed finishes are available to suit the service environment.
A: Both grades share the same high-molybdenum chemistry, but 317L has a lower maximum carbon content (0.03% vs 0.08%). That low carbon prevents chromium-carbide precipitation during welding, so 317L is chosen for welded assemblies while 317 suits non-welded, higher-strength applications.
A: Yes, in aggressive chloride and acid environments. The extra molybdenum (3–4% vs 2–3% in 316L) gives 317L noticeably higher pitting and crevice-corrosion resistance, making it a step up for chemical, marine and FGD service.
A: Our bolts are manufactured to ASTM A193 / A194 and ASME SA-193 / SA-194, with dimensions to DIN, ISO and ASME B18 series. Each lot ships with an EN 10204 3.1 mill test certificate.
A: Standard production covers M2 to M56 (3/16" to 2") in lengths from 3 mm to 200 mm. Custom sizes, threads and finishes are made to order.
A: 317 is UNS S31700 / EN 1.4449, and 317L is UNS S31703 / EN 1.4438.
A: Yes. We provide ASTM A194 317/317L hex, heavy hex, jam and nylock nuts plus flat, spring and structural washers so the full joint is corrosion-matched.
Unifit Fastener stocks and manufactures Stainless Steel 317 / 317L bolts, nuts, studs and washers — dual-certified, batch-traceable and export-ready.
Contact: chirag@unifitmetalloys.com | Call / WhatsApp for immediate assistance Request a Same-Day Quote
