# SUS 316 Forgings (JIS G4303 / UNS S31600 / EN 1.4401)

Source: https://www.steelforgepieces.com/Stainless-Steel/SUS-316.html
Supplier: Jiangyin Jiangnan Metal Co., Ltd., open-die forging works, Jiangyin, Jiangsu, China
Updated: 3 October 2026

We melt and open-die forge SUS 316 to customer drawings at our works in Jiangyin, Jiangsu. Forms include seamless rolled rings, forged flanges, shafts, round bars, discs, tube sheets, sleeves, bushings and valve parts, supplied solution annealed with EN 10204 3.1 or 3.2 certification.

## Data summary

| Item | Value |
| --- | --- |
| Grade designation | SUS 316 (JIS G 4303, stainless steel bars) |
| Forging designation | SUS F316 (JIS G 3214), ASTM A182 F316 |
| UNS number | S31600 |
| European equivalent | EN 1.4401, X5CrNiMo 17-12-2 |
| Chinese equivalent | GB 06Cr17Ni12Mo2 (S31608) |
| Structure | Austenitic, molybdenum-bearing, not hardenable by heat treatment |
| Cr / Ni / Mo | 16.0-18.0 / 10.0-14.0 / 2.00-3.00 % |
| Tensile strength, min | 520 MPa (JIS G 4303 bar); 515 MPa (ASTM A240 and A182 F316) |
| Yield strength 0.2%, min | 205 MPa (30 ksi) |
| Elongation, min | 40% (JIS bar and ASTM A240); 30% (ASTM A182 F316) |
| Hardness, max | 187 HBW (JIS G 4303 bar); 217 HB / 95 HRB (ASTM A240) |
| PREN | about 24 to 26 |
| Heat treatment | Solution anneal 1010-1120 C, cool rapidly |
| Oxidation resistance | 870 C intermittent, 925 C continuous |
| Density / Elastic modulus | 8000 kg/m3 / 193 GPa |
| Low-carbon version | SUS 316L (UNS S31603, EN 1.4404) |

## What SUS 316 is

SUS 316 is the Japanese Industrial Standard name for the molybdenum-bearing austenitic stainless steel sold elsewhere as Type 316, UNS S31600 and EN 1.4401. It is SUS 304 with 2 to 3% molybdenum added, and that addition is the whole reason the grade exists. Molybdenum gives 316 better overall corrosion resistance than 304 and, in particular, higher resistance to pitting and crevice corrosion in chloride environments. After 304 it is the most used austenitic stainless steel.

The austenitic structure brings excellent toughness, held down to cryogenic temperatures, along with excellent forming and welding behaviour. Like every austenitic stainless, SUS 316 cannot be hardened by thermal treatment. Strength comes from the chemistry and from cold work, not from a quench.

### Which standard are you buying to?

SUS 316 on its own is a chemistry, not a product specification. Acceptance values shift with the standard named on the order. A ring bought as JIS G 4303 bar stock, as ASTM A182 F316 forgings or as JIS G 3214 SUS F316 pressure-vessel forgings carries the same chemistry but different minimum elongation and hardness limits.

| Standard | Product covered | Tensile, min | Yield 0.2%, min | Elongation, min | Hardness, max |
| --- | --- | --- | --- | --- | --- |
| JIS G 4303, SUS 316 | Bars, d or t up to 180 mm | 520 MPa | 205 MPa | 40% | 187 HBW |
| ASTM A240, Type 316 | Plate, sheet, coil | 515 MPa (75 ksi) | 205 MPa (30 ksi) | 40% in 50 mm | 217 HB / 95 HRB |
| ASTM A182, F316 | Forged flanges, fittings, valves, parts | 515 MPa (75 ksi) | 205 MPa (30 ksi) | 30% in 50 mm | - |

Note on elongation: A182 F316 asks for 30% elongation and 50% reduction of area, not the 40% quoted for bar and plate. The lower figure allows for heavier sections and for test pieces cut across the grain flow. If a drawing calls out 40% on a large forged ring, say so at enquiry stage so the test-piece location and the forging reduction ratio can be planned around it.

## Chemical composition, weight %

| Element | JIS G 4303 (SUS 316) | ASTM A240 (316) | ASTM A182 (F316) |
| --- | --- | --- | --- |
| Carbon (C) | 0.08 max | 0.08 max | 0.08 max |
| Silicon (Si) | 1.00 max | 0.75 max | 1.00 max |
| Manganese (Mn) | 2.00 max | 2.00 max | 2.00 max |
| Phosphorus (P) | 0.045 max | 0.045 max | 0.045 max |
| Sulfur (S) | 0.030 max | 0.030 max | 0.030 max |
| Chromium (Cr) | 16.00-18.00 | 16.00-18.00 | 16.00-18.00 |
| Nickel (Ni) | 10.00-14.00 | 10.00-14.00 | 10.00-14.00 |
| Molybdenum (Mo) | 2.00-3.00 | 2.00-3.00 | 2.00-3.00 |
| Nitrogen (N) | - | 0.10 max | 0.10 max |
| Iron (Fe) | Balance | Balance | Balance |

Silicon warning: JIS G 4303 and A182 F316 both allow silicon to 1.00%; A240 plate stops at 0.75%. A heat that is sound as SUS 316 bar can fail an A240 product analysis on silicon alone. We aim the ladle at the tightest limit written on the order.

### Melting route

SUS 316 is melted in a 25 t electric arc furnace, refined in a 25 t or 50 t ladle furnace, then decarburised under vacuum in a 30 t or 60 t VOD unit. VOD is what pulls carbon down reliably and keeps nitrogen and residuals in hand. Maximum heat size 60 tonnes. Electroslag remelting in 3 t or 6 t protective-atmosphere furnaces is available where a specification demands tighter cleanliness, though standard SUS 316 rarely calls for it.

## Physical properties

| Property | Value | Condition |
| --- | --- | --- |
| Density | 8000 kg/m3 | Room temperature |
| Elastic modulus | 193 GPa | Room temperature |
| Thermal expansion, mean | 15.9 um/m/C | 0-100 C |
| Thermal expansion, mean | 16.2 um/m/C | 0-315 C |
| Thermal expansion, mean | 17.5 um/m/C | 0-538 C |
| Thermal conductivity | 16.3 W/m.K | 100 C |
| Thermal conductivity | 21.5 W/m.K | 500 C |
| Specific heat | 500 J/kg.K | 0-100 C |
| Electrical resistivity | 740 nOhm.m | Room temperature |

## Corrosion and heat resistance

Chlorides: 316 pits and suffers crevice attack in warm chlorides and cracks under stress corrosion above roughly 60 C. It is taken as resistant to potable water with up to about 1000 mg/L chlorides at ambient temperature, falling to about 500 mg/L at 60 C. The grade is usually called the standard marine stainless, but it is not resistant to warm sea water, and in many marine settings it stains brown at crevices and on rough finishes. PREN = %Cr + 3.3 x %Mo + 16 x %N, giving roughly 24 to 26. That covers light coastal exposure, not submerged service, crevice-heavy assemblies or high-chloride process duty.

Elevated temperature: oxidation resistance is good to 870 C intermittent and 925 C continuous. Continuous service between 425 and 860 C is not advised where aqueous corrosion resistance still matters afterwards, because carbide precipitation in that band sensitises the steel. Use 316L in that case, or 316H where load is carried above about 500 C.

## Forging practice, heat treatment, machining

Solution annealing means heating to 1010-1120 C and cooling fast, to put chromium carbides back into solution and leave a fully austenitic structure. The cooling rate through the sensitising band decides the result, so on heavy rings and thick discs the section thickness and the quench tank matter as much as the furnace setting. There is no quench-and-temper route for raising strength.

Heat-treatment shop: 14 furnaces. Car-bottom furnaces take work to 8,000 x 2,000 x 2,000 mm. Two well furnaces 15 m deep allow long shafts to be solution treated and quenched vertically, which avoids the bow that comes from quenching a long shaft on its side.

Welding: 316 welds by all standard fusion methods, with or without filler; thin sections need no post-weld anneal, heavy welded sections do. 316L and 316Ti are the alternatives for heavy welded section.

Machining: 316 work hardens and is gummy, needing sharp tooling, rigid setups and plenty of coolant. An improved-machinability version exists in round and hollow bar, but that is a mill product rather than something produced from a forged ingot. Forgings are supplied as-forged with allowance, proof-machined for ultrasonic inspection, or finish-machined on vertical lathes to 5,000 mm swing and horizontal lathes to 14 m between centres.

## Equivalent grades

| Country or system | Designation |
| --- | --- |
| Japan, JIS | SUS 316; SUS F316 (G 3214 forgings) |
| USA, ASTM and AISI | 316; A182 F316 |
| USA, UNS | S31600 |
| Europe, EN name | X5CrNiMo 17-12-2 |
| Europe, EN number | 1.4401 |
| China, GB | 06Cr17Ni12Mo2, ISC S31608 |
| South Korea, KS | STS 316 |
| United Kingdom, BS | 316S31, 316S16 |
| France, NF | Z6CND 17-11, Z6CND 17-12 |
| Sweden, SS | 2347 |
| Russia, GOST | 08Kh17N13M2T |
| ISO | X5CrNiMo 17-12-2, 4401-316-00-I |

These are functionally similar materials, not contractual equivalents. Where an exact equivalent is required, the original specification has to be consulted and named on the order. We certify to the specification you name, not to a cross-reference table.

### 316, 316L and 316H

- SUS 316 / S31600: carbon 0.08% max, general purpose, heavy welded sections need a post-weld anneal.
- SUS 316L / S31603: carbon 0.03% max, immune from sensitisation, used in heavy-gauge welded components over about 6 mm. Tensile 485 MPa min, yield 170 MPa min.
- 316H / S31609: carbon 0.04-0.10%, higher strength above about 500 C, grain size ASTM No. 7 or coarser.

316 and 316L are often stocked dual certified. Dual certified material does not meet 316H and may be unacceptable at high temperature.

## When SUS 316 is not enough

| Grade | Reason to move up |
| --- | --- |
| 316Ti | Better behaviour around 600-900 C |
| 316N | Higher strength than standard 316 |
| 317L | Higher chloride resistance than 316L at similar SCC resistance |
| 904L | Much higher chloride resistance at elevated temperature, good formability |
| A182 F51 (duplex 2205) | Much higher chloride resistance, roughly double the yield strength |
| A182 F55 (super duplex) | Severe seawater and sour service, PREN above 40 |
| A182 F44 (6% Mo) | Warm seawater and strongly oxidising chloride service |

All of the above are forged at our works.

## Product forms

Seamless rolled rings, radial-axial rolled OD 50 to 6,000 mm, rectangular or contoured section. Forged flanges: weld neck, slip-on, blind, long weld neck, lap joint, orifice, spectacle blind and spacer, to ASME B16.5, B16.47, EN 1092-1 and JIS B2220. Shafts and spindles turned to 14 m. Discs, tube sheets and covers to 5,000 mm machined diameter. Round bars and blocks. Sleeves, bushings and cylinders bored from solid to 1,600 x 10,000 mm. Valve bodies, bonnets, seat rings, stems and blocks. Custom open-die work on 6,300 t, 4,000 t and 2,000 t presses.

Size envelope: heaviest single forging 30 tonnes, largest rolled ring OD 6,000 mm, smallest ring OD 50 mm by the upset-and-punch route, longest turned shaft 14 m, minimum order 10 kg with no minimum piece count.

## Applications

Typical uses for the grade include food preparation equipment in chloride environments, laboratory benches and equipment, coastal architectural panelling, railings and trim, boat fittings, chemical containers including transport tanks, heat exchangers, woven and welded screens for mining, quarrying and water filtration, threaded fasteners and springs.

In forged form: chemical and petrochemical pressure vessel flanges, nozzles, tube sheets, covers, piping, pump and valve parts; food, dairy and pharmaceutical agitator and mixer shafts, vessel parts and sanitary flanges; pulp and paper digester components, liquor tank parts, machine rolls and shafts; marine and coastal deck hardware and shafting above the waterline; water treatment pump casings, impeller hubs, flanges and shafts; power and rotating equipment gear blanks, spindles, recuperator and heat-exchanger parts.

## Testing and certification

| Test | Standard or method | Performed |
| --- | --- | --- |
| Chemical analysis | ASTM E415 optical emission; ASTM E1019 for C and S | In-house |
| Positive material identification | Handheld alloy analyser | In-house |
| Tension test | ASTM A370, ISO 6892, 600 kN and 300 kN machines | In-house |
| Impact test | Charpy V-notch to ASTM A370, to -60 C | In-house |
| Hardness | ASTM A956 Leeb, converted per ASTM E140 | In-house or third party |
| Grain size and metallography | ASTM E112 | In-house |
| Ultrasonic testing | ASTM A388, EN 10228-3, SEP 1921 | In-house |
| Magnetic particle and liquid penetrant | ASTM E709 and equivalent | In-house |
| Intergranular corrosion | ASTM A262, ASTM G28 | Third-party laboratory |
| Pitting corrosion | ASTM G48 | Third-party laboratory |
| Certification | EN 10204 3.1 standard; 3.2 witnessed by BV, DNV, LR, SGS, TUV or your inspector | - |

The works holds CCS, BV, DNV, LR and NK approvals. Heat-treatment charts, NDT reports, dimensional reports and PMI records go out with the certificate. Intergranular corrosion testing to ASTM A262 is the item most often left off a 316 order and most often demanded at inspection.

## Requesting a quotation

Quote returned within two working days of a complete enquiry. Minimum order 10 kg, no minimum piece count. Lead time 20 to 60 days, SUS 316 at the lower end because it is melted and forged without an intermediate remelting step.

Include: material grade and governing specification; dimensions or a drawing in PDF, DWG, DXF or STEP; quantity and repeat volume; delivery condition (as-forged, proof-machined or finish-machined); heat treatment and testing; certification level and destination port.

## FAQ

**Is SUS 316 the same as AISI 316, UNS S31600 and EN 1.4401?**
In practical terms, yes. SUS 316 is the JIS name for the molybdenum-bearing austenitic stainless steel known as AISI and ASTM Type 316, UNS S31600 and EN 1.4401, X5CrNiMo 17-12-2. The Chinese equivalent is GB 06Cr17Ni12Mo2, S31608. The chemistry ranges match closely, but detailed limits and acceptance values differ between standards, so name the governing specification on the purchase order.

**What is the difference between SUS 316 and SUS 304?**
Molybdenum, 2 to 3%, which SUS 304 does not have, plus slightly more nickel. That gives 316 much higher resistance to pitting and crevice corrosion in chlorides. Both are austenitic and cannot be hardened by heat treatment.

**What are the mechanical properties of SUS 316?**
JIS G 4303 bar to 180 mm: 520 MPa tensile, 205 MPa yield, 40% elongation, 60% reduction of area, 187 HBW max. ASTM A240: 515 MPa tensile, 205 MPa yield, 40% elongation, 217 HB or 95 HRB max. ASTM A182 F316: 515 MPa tensile, 205 MPa yield, 30% elongation, 50% reduction of area.

**Is SUS 316 suitable for seawater?**
Not for warm or stagnant seawater. It pits and suffers crevice corrosion in warm chlorides and cracks under stress corrosion above about 60 C. Resistant to about 1000 mg/L chlorides at ambient temperature, about 500 mg/L at 60 C. For seawater duty use duplex, super duplex or a 6% molybdenum grade.

**Should I specify SUS 316 or SUS 316L?**
316L for heavy welded sections, or service between 425 and 860 C followed by wet corrosion duty. Otherwise 316, for its higher minimum strength. Dual certified 316/316L satisfies both but not 316H.

**How is SUS 316 heat treated after forging?**
Solution anneal at 1010-1120 C, cool rapidly. The grade does not respond to quench and temper. On heavy rings and thick discs the cooling rate through the sensitising band is the controlling variable.

**What is the largest SUS 316 forging you can make?**
Rings to OD 6,000 mm on the 6 m radial-axial mill, single pieces to 30 tonnes on 6,300 t, 4,000 t and 2,000 t presses, shafts turned to 14 m, melt-shop heat size to 60 tonnes.

**Do you melt your own SUS 316?**
Yes, through a 25 t EAF, 25 t and 50 t ladle furnaces and 30 t or 60 t VOD units. Traceability runs from melt number to shipped part, and the ladle chemistry can be aimed at the tightest limit on the order.

**What certification is supplied?**
EN 10204 3.1 as standard, 3.2 witnessed by BV, DNV, LR, SGS, TUV or your own inspector on request. CCS, BV, DNV, LR and NK approvals held.

**Minimum order and lead time?**
10 kg minimum, no minimum piece count. 20 to 60 days, SUS 316 at the lower end.

## Contact

Jiangyin Jiangnan Metal Co., Ltd.
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China 214423
Telephone, WhatsApp, WeChat: +86 189-2135-9659
Email: sales@steelforgepieces.com
Hours: Monday to Saturday, 08:00-17:30 China Standard Time (UTC+8)
Established 1997. 460 staff. Approvals: CCS, BV, DNV, LR, NK.