OverviewWhat AISI 316H is, in one paragraph
AISI 316H is the high carbon version of 316 austenitic stainless steel, specified as UNS S31609 and forged to ASTM A182 Grade F316H. Carbon is controlled to 0.04 to 0.10 percent with a deliberate minimum rather than simply a ceiling, which raises tensile and yield strength and improves both short and long term creep strength. It is developed for elevated temperature service and is used for structural and pressure vessel applications above 932 F (500 C), while retaining the molybdenum bearing corrosion resistance of 316 and excellent austenitic toughness down to cryogenic temperatures. Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory in Jiangyin, Jiangsu, China, supplies this grade as forged flanges, seamless rolled rings, shafts, discs, sleeves, bushings, bars, tube sheets and forged pipes, solution annealed and certified to EN 10204-3.1 or 3.2.
- Grade type
- Austenitic chromium nickel molybdenum stainless steel, high carbon variant of 316
- UNS number
- S31609
- Forging standard
- ASTM A182 / ASME SA-182 Grade F316H
- Plate standard
- ASTM A240 / ASME SA-240 Type 316H
- Hardenable
- No. Cannot be hardened by heat treatment; strengthens by cold work only
- Magnetic response
- Non-magnetic as annealed; may become slightly magnetic after cold work
- Melting route
- EAF plus VOD, ESR available on request
Grade selection316 compared with 316L and 316H
This is the comparison that decides most orders. All three grades share the same chromium, nickel and molybdenum base, and their corrosion resistance is comparable; the corrosion resistance of 316H is on a par with 316 and 316L and superior to 304 and 304L in moderately corrosive environments. Carbon is the whole difference.
| Item | 316L | 316 | 316H |
|---|---|---|---|
| Carbon, percent | 0.030 max | 0.08 max | 0.04 to 0.10 |
| Nitrogen, percent | 0.10 max | 0.10 max | not specified |
| Chromium, nickel, molybdenum | identical base | identical base | identical base |
| Strength at temperature | lowest | intermediate | highest of the three |
| Creep strength | lowest | intermediate | best, short and long term |
| Resistance to sensitisation | best | intermediate | most susceptible |
| Usual selection driver | welding, intergranular corrosion | general service | service above 500 C |
The trade-off to understand before you specify. The same carbon that pins the austenitic grain boundaries and delivers creep strength also makes 316H more prone to sensitisation during welding, which can lead to intergranular corrosion. If the part is welded, see the fabrication section below; if the duty is below 500 C and welding is extensive, 316L is often the better engineering choice despite its lower strength.
DesignationsEquivalent grades and specifications
| System | Designation | Covers |
|---|---|---|
| AISI and commercial | AISI 316H, Type 316H, Alloy 316H | Grade name |
| UNS | S31609 | All forms |
| ASTM and ASME | A182 / SA-182 Grade F316H | Forgings: flanges, fittings, valve bodies, rings, bars, pressure parts |
| ASTM and ASME | A240 / SA-240 Type 316H | Plate, sheet and strip |
| EN | 1.4919 | European equivalent |
| JIS | SUS 316H | Japanese equivalent |
| BS | 316S51 | British equivalent |
A note on the European number: 1.4919 is the equivalent cited for 316H by most European stockholder data. Some mill data sheets instead print 1.4401 against 316H, but 1.4401 is the number for standard 316, so treat a 1.4401 certificate as requiring confirmation of the actual carbon result before accepting it against a 316H order.
CompositionChemical composition, weight percent
The limits below are identical between the forging and plate specifications apart from silicon, which is the detail most often missed at enquiry stage. Tell us which standard your drawing invokes and we melt to that window.
| Element | A182 F316H, forgings | A240 Type 316H, plate |
|---|---|---|
| Carbon (C) | 0.04 to 0.10 | 0.04 to 0.10 |
| Chromium (Cr) | 16.0 to 18.0 | 16.0 to 18.0 |
| Nickel (Ni) | 10.0 to 14.0 | 10.0 to 14.0 |
| Molybdenum (Mo) | 2.00 to 3.00 | 2.00 to 3.00 |
| Manganese (Mn) | 2.00 max | 2.00 max |
| Silicon (Si) | 1.00 max | 0.75 max |
| Phosphorus (P) | 0.045 max | 0.045 max |
| Sulphur (S) | 0.030 max | 0.030 max |
| Iron (Fe) | balance | balance |
316H also carries a grain size requirement of ASTM No. 7 or coarser, a deliberate choice because coarser grains improve creep performance. This is a genuine acceptance criterion, not a nicety, and we report it on the certificate when the order calls for it.
PropertiesMechanical and physical properties
316H is delivered in one condition, solution annealed, so there is no condition code to choose as there is with the precipitation hardening grades. The figures below are specification minima except where marked as a maximum.
| Property | A182 F316H forgings | A240 Type 316H plate |
|---|---|---|
| Tensile strength, min | 515 MPa (75 ksi) | 515 MPa (75,000 psi) |
| Yield strength 0.2 percent, min | 205 MPa (30 ksi) | 205 MPa (30,000 psi) |
| Elongation, min | 30 percent in 50 mm or 4D | 40 percent in 50 mm |
| Reduction of area, min | 50 percent | not listed |
| Hardness, max | not listed | 217 HB / 95 HRB |
Physical properties
| Property | Metric | Imperial |
|---|---|---|
| Density | 8.00 g/cm³ | 0.285 lb/in³ |
| Modulus of elasticity | 200 GPa | 29.0 × 10⁶ psi |
| Melting range | 1375 to 1400 C | 2507 to 2552 F |
| Thermal conductivity at 100 C | 15 W/m·K | 8.7 BTU/hr/ft²/ft/F |
| Specific heat, 0 to 100 C | 500 J/kg·K | 0.11 BTU/lb·F |
| Mean thermal expansion, 20 to 100 C | 16.0 × 10⁻⁶ /C | 8.9 × 10⁻⁶ /F |
| Electrical resistivity at 20 C | 74 microhm·cm | 29.1 microhm·in |
Elevated temperature allowable stresses are not reproduced here because they are code values. If your design is to ASME BPVC, take the allowables from the applicable section and tell us the design temperature so we can advise on testing and documentation.
CorrosionCorrosion behaviour and where it is limited
316H resists atmospheric corrosion along with moderately oxidising and reducing environments, and it performs well in polluted marine conditions and in fresh water service even at high chloride levels. The molybdenum content gives it better pitting resistance than 304 and 304L in chloride solutions, particularly oxidising ones. It also has good resistance to pitting in phosphoric and acetic acids and performs well in boiling 20 percent phosphoric acid, and it holds up in sulphur bearing service of the kind found in pulp and paper work, where it can be used in high concentrations at temperatures up to 120 F (38 C). In food and pharmaceutical processing it is used to handle hot organic and fatty acids where product contamination is a concern.
The honest limitation is highly oxidising acids. In media such as nitric acid, molybdenum bearing stainless steels are less resistant than molybdenum free grades, so 316H is the wrong selection there. As a general rule, process environments that do not attack 304 and 304L will not attack this grade, with that nitric acid exception.
| Index | Value | Basis |
|---|---|---|
| Pitting resistance equivalent, PRE | 24 | PRE = %Cr + 3.3 × %Mo + 16 × %N |
| Critical pitting temperature, CPT | 20 ± 2 C | ASTM G150, 1M NaCl |
| Critical crevice temperature, CCT | below 0 C | ASTM G48 Method F |
FabricationForging, annealing, welding and machining
Hot forging and annealing
Recommended working temperatures for most hot working processes are 1700 to 2200 F (927 to 1204 C). For maximum corrosion resistance the alloy should then be annealed at 1038 C (1900 F) minimum and water quenched or cooled rapidly by other means. Because 316H gains nothing from a hardening cycle, the annealing step is not a formality: it is what restores corrosion resistance and dissolves carbides after hot work, and it is the condition in which we deliver unless your order says otherwise. Forging reduction and the upset and draw sequence are planned per part so that grain flow follows the principal stress direction, and ring rolling schedules are set to suit the finished section.
Welding
316H can be readily welded by most standard processes and a post weld heat treatment is not strictly necessary. The caveat is the one that follows from its carbon: there is a risk of sensitisation, which can lead to intergranular corrosion in service. Where that risk matters, the usual mitigations are a post weld solution anneal or the use of a low carbon filler such as 316L. Tell us at enquiry stage whether the forging will be welded into an assembly, since it can change both the delivery condition and the testing we recommend.
Cold forming and machining
The alloy is quite ductile and forms easily, but cold work raises strength and hardness and may leave the material slightly magnetic. In machining it work hardens during deformation and gives trouble with chip breaking. The best results come from slower speeds, heavier feeds, generous lubrication, sharp tooling and powerful rigid equipment. As a starting point for turning, high speed steel tooling with cutting oil runs at roughly 11 to 16 m/min at 6 mm depth of cut, rising to 25 to 30 m/min at 1 mm, while carbide runs far faster at about 70 to 80 m/min at 6 mm depth and 100 to 110 m/min at 1 mm. Treat these as starting points for your own machine and tooling rather than as settings.
Product rangeAISI 316H forged forms we supply
All items are made to customer drawing or specification. Send the part envelope and we will confirm feasibility, forged weight and lead time.
ApplicationsWhere AISI 316H forgings are used
QualityInspection, testing and certificates
Each forging is ultrasonically tested to the acceptance class stated on the order, to EN 10228-3, SEP 1921 or ASTM A388. Tensile and hardness testing are standard. Because this grade is bought for high temperature duty and for corrosive service, three optional tests are worth considering at enquiry stage: grain size determination against the ASTM No. 7 or coarser requirement, intergranular corrosion testing to ASTM A262 where sensitisation is a concern, and positive material identification to separate 316H from 316 and 316L on receipt, since the three are visually identical and differ only in carbon. Magnetic particle and dye penetrant inspection are also available.
Documents are issued as EN 10204-3.1 inspection certificates, or EN 10204-3.2 witnessed and endorsed by the third party inspection body you nominate. Heat number traceability runs from melt through solution annealing to final machining.
QuestionsFrequently asked questions
What is the difference between 316, 316L and 316H?
Carbon, and what carbon does. 316L holds carbon to 0.030 percent maximum for weldability and resistance to intergranular corrosion, standard 316 allows up to 0.08 percent, and 316H specifies 0.04 to 0.10 percent with a deliberate minimum. That minimum gives 316H higher tensile and yield strength and better short and long term creep strength. Corrosion resistance across the three is comparable because the chromium, nickel and molybdenum base is the same.
Which standard covers AISI 316H forgings?
ASTM A182 or ASME SA-182 Grade F316H, which is the specification for forged flanges, fittings, valve bodies, rings, bars and similar pressure parts. ASTM A240 and ASME SA-240 cover 316H plate, sheet and strip. The two agree on composition except silicon, which is 1.00 percent maximum in A182 and 0.75 percent maximum in A240, so name the governing document on your order.
What are the mechanical requirements of A182 F316H?
Minimum tensile strength 515 MPa (75 ksi), minimum 0.2 percent yield strength 205 MPa (30 ksi), minimum elongation 30 percent in 50 mm or 4D, and minimum reduction of area 50 percent. Plate to A240 carries the same strength minima with 40 percent elongation and a hardness ceiling of 217 HB or 95 HRB.
At what temperature should I choose 316H over 316L?
316H is developed for elevated temperature service and is used for structural and pressure vessel applications above 932 F (500 C). Below that, and especially where welding is extensive and intergranular corrosion is a concern, the lower carbon grades are often the better choice. Where a design sits near the boundary, the decision usually turns on whether creep strength or weld sensitisation is the greater risk.
Can 316H be hardened by heat treatment?
No. It is austenitic, cannot be hardened by heat treatment, and strengthens only through cold work. It is non-magnetic in the annealed condition and may become slightly magnetic after cold working. For maximum corrosion resistance it should be annealed at 1038 C (1900 F) minimum followed by water quenching or other rapid cooling.
Is 316H suitable for cryogenic service?
Yes. The austenitic structure gives excellent toughness down to cryogenic temperatures, so although the grade is specified mainly for high temperature strength it is also used at low temperatures. Confirm with us if your order needs impact testing at a specified low temperature, as that affects the test plan.
How do I get a quotation?
Email the drawing or dimensions to sales@steelforgepieces.com or call +86-189-2135-9659. Include the grade and governing standard, quantity, machining allowance, ultrasonic acceptance class, any grain size or corrosion testing required, and the certificate type, EN 10204-3.1 or 3.2. We normally reply within one working day with price, forged weight and lead time.
Request a quotation for AISI 316H forgings
Send the size or drawing of the part you need and we will quote our best price, with forged weight, lead time and testing scope confirmed in writing.
- Grade and governing standard, for example A182 F316H
- Quantity and machining allowance
- Ultrasonic acceptance class and any corrosion or grain size testing
- Certificate type, EN 10204-3.1 or 3.2
Open-die forging factory AddressNo.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China Telephone and WhatsApp+86-189-2135-9659 Emailsales@steelforgepieces.com
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Page maintained by the engineering department of Jiangyin Jiangnan Metal Co., Ltd. Published 20 May 2024. Last reviewed 1 October 2026. Property values are specification minima and published typical data for AISI 316H and are given for guidance only. Contractual values are those stated on the order and on the material test certificate.