# ASTM A182 F316L Forgings (UNS S31603) **Supplier:** Jiangyin Jiangnan Metal Co., Ltd., open-die forging factory **Address:** No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China **Telephone:** +86 189 2135 9659 **Email:** sales@steelforgepieces.com **Page:** https://www.steelforgepieces.com/Stainless-Steel/A182-F316L.html **Last reviewed:** 2026-09-29 --- ASTM A182 Grade F316L is the forging specification for low-carbon 316L stainless steel, used for pipe flanges, forged fittings, valves and pressure parts. Carbon is held to 0.030 % maximum, which keeps chromium carbides out of the grain boundaries when the part is welded, and 2.00 to 3.00 % molybdenum raises pitting resistance in chloride service well above 304L. Jiangyin Jiangnan Metal Co., Ltd. forges F316L to customer drawing as seamless rolled rings, flanges, bars, hollow bars, discs, blocks, sleeves, tube sheets and shafts. ## A182 F316L at a glance - **Designation:** F316L is the grade symbol in ASTM A182. The matching UNS number is S31603. - **Chemistry:** 0.030 % C max, 16.0 to 18.0 % Cr, 10.0 to 15.0 % Ni, 2.00 to 3.00 % Mo, 2.00 % Mn max, 1.00 % Si max, 0.10 % N max, balance Fe. - **ASTM minima:** 70 ksi [485 MPa] tensile, 25 ksi [170 MPa] yield, 30 % elongation, 50 % reduction of area. Over 5 in. [130 mm] section the tensile minimum is 65 ksi [450 MPa]. - **Heat treatment:** solution treat and quench, 1900 F [1040 C] minimum. - **Equivalents:** AISI 316L, EN 1.4404, X2CrNiMo17-12-2. - **Minimum order:** one piece, forged to drawing. - **Certificate:** EN 10204 3.1 as standard, 3.2 with third-party inspection on request. ## What is ASTM A182 F316L? A182 F316L is 316L stainless steel written into a forging specification. ASTM A182 sets what the forge shop has to deliver: the analysis, the heat-treated condition, the mechanical acceptance, the testing and the marking. A drawing that calls for F316L rather than 316L is asking for a forged or rolled product certified to that specification, not only for a material with 316L chemistry. Two limits define the grade. Carbon at 0.030 % maximum, against 0.08 % for standard F316, starves the reaction that precipitates chromium carbides at grain boundaries while a weld cools through roughly 450 to 850 C. Molybdenum at 2.00 to 3.00 % is the addition that separates the 316 family from 304 and holds the passive film together against chloride pitting and crevice attack. Low carbon costs strength, which is why some designers move to F316LN and buy it back with nitrogen. ## A182 F316L chemical composition Ladle analysis to ASTM A182, weight percent, balance iron. | Element | Symbol | Min % | Max % | Function | |---|---|---|---|---| | Carbon | C | - | 0.030 | Held low to keep carbides out of the grain boundaries during welding | | Chromium | Cr | 16.0 | 18.0 | Forms the passive film | | Nickel | Ni | 10.0 | 15.0 | Holds the austenitic structure, adds toughness | | Molybdenum | Mo | 2.00 | 3.00 | Pitting and crevice resistance in chlorides | | Manganese | Mn | - | 2.00 | Deoxidiser, austenite stabiliser | | Silicon | Si | - | 1.00 | Deoxidiser | | Nitrogen | N | - | 0.10 | Interstitial strengthener | | Phosphorus | P | - | 0.045 | Residual, limited to protect hot ductility | | Sulphur | S | - | 0.030 | Residual, limited to protect weldability | F316L is specified 10.0 to 15.0 % Ni, wider at the top than the 10.0 to 14.0 % allowed for F316, because extra nickel helps hold austenite stable at the lower carbon level. Product analysis on a finished forging may deviate within the tolerances of the standard. Every heat ships with its own certificate of analysis. PREN, taken as %Cr + 3.3 x %Mo + 16 x %N, puts a typical F316L heat in the mid-20s: above 304L, below the 6 % molybdenum and duplex grades. ## A182 F316L mechanical properties ASTM A182 acceptance requirements at room temperature. | Property | Minimum, US | Minimum, metric | |---|---|---| | Tensile strength | 70 ksi | 485 MPa | | Tensile strength, sections over 5 in. [130 mm] | 65 ksi | 450 MPa | | Yield strength, 0.2 % offset | 25 ksi | 170 MPa | | Elongation in 2 in. [50 mm] or 4D | 30 % | 30 % | | Reduction of area | 50 % | 50 % | These are acceptance minima, not typical test results. ASTM A182 does not set a Brinell range for the austenitic grades, so hardness is reported as measured unless your specification states a band. Indicative density is approximately 7.98 g/cm3. The structure is austenitic and cannot be hardened by heat treatment. ## A182 F316L heat treatment | Operation | Temperature | Cooling | Purpose | |---|---|---|---| | Solution treat and quench | 1900 F [1040 C] minimum | Rapid quench, water or forced air by section | The ASTM delivery condition. Takes carbides into solution and restores corrosion resistance | | Low-temperature stress relief | Below the sensitising range | Air | Relieve machining or welding stress without bringing carbides back out | What counts is the cooling, not the soak. The quench has to move the forging through roughly 450 to 850 C fast enough that carbides have no chance to reform at the grain boundaries, which on heavy sections means a real water quench started without delay. A forging that spent too long in transfer can pass its tensile test and still fail an ASTM A262 test. There is no conventional stress-relief window of the kind a carbon steel has, because time in the sensitising range undoes the solution anneal. ## Forging A182 F316L | Parameter | Value | |---|---| | Start forging temperature | 1150 to 1200 C | | Finish forging temperature | not below 950 C | | Minimum forging ratio | 3:1, higher on request | | Post-forge cooling | Air cool, then solution treat and quench | | Delivery condition | Solution annealed as standard | Austenitic stainless stays stiff at temperature, so the press works harder for the same reduction and the window at the low end is narrower. Finishing too cold leaves residual strain and risks cracking. Finishing too hot leaves a coarse grain that shows up later as poor ultrasonic response. Ring geometries are pierced and then rolled radially and axially, which runs the grain flow around the circumference instead of cutting across it. ## What is A182 F316L equivalent to? Indicative comparison, not a certified substitution. | System | Designation | How close | |---|---|---| | ASTM A182 (USA) | F316L | The grade itself | | UNS | S31603 | Same steel in UNS number form | | AISI / SAE (USA) | 316L | Same analysis, general grade designation | | EN material number | 1.4404 | European counterpart of 316L | | EN name | X2CrNiMo17-12-2 | Same steel as 1.4404 in name form | | EN material number | 1.4435 | Close neighbour, richer in nickel and molybdenum | Mechanical acceptance, permitted residuals, product-form scope and pressure-equipment approval all differ between ASTM and EN. A 1.4404 certificate does not automatically satisfy a drawing calling for A182 F316L. ### F316L compared with the rest of the A182 316 group | Grade | UNS | Carbon % max | Nitrogen % | Tensile min. | Yield min. | |---|---|---|---|---|---| | F316L | S31603 | 0.030 | 0.10 max | 70 ksi [485 MPa] | 25 ksi [170 MPa] | | F316 | S31600 | 0.08 | 0.10 max | 75 ksi [515 MPa] | 30 ksi [205 MPa] | | F316LN | S31653 | 0.030 | 0.10 to 0.16 | 75 ksi [515 MPa] | 30 ksi [205 MPa] | | F316N | S31651 | 0.08 | 0.10 to 0.16 | 80 ksi [550 MPa] | 35 ksi [240 MPa] | | F316H | S31609 | 0.04 to 0.10 | not specified | 75 ksi [515 MPa] | 30 ksi [205 MPa] | Take F316 when you need the strength and welding is controlled. Take F316L when the assembly is welded and cannot be re-annealed. Take F316LN when a code calculation fails on the low yield of F316L but the low carbon still has to stay. Against F304L the difference is molybdenum: in chloride-bearing service F316L holds out at a higher threshold before it pits, while in clean water or steam duty F304L usually does the same job for less money. ## Corrosion behaviour and where the grade stops F316L handles general corrosion across a wide span of process chemistry, and its recognised strength is resistance to intergranular attack in the as-welded condition. The limits matter as much. Chloride stress corrosion cracking is the classic failure mode for every standard austenitic and becomes a live risk above roughly 60 C in chloride solutions under tensile stress. Crevice geometry under gaskets and deposits will start attack at conditions the open surface tolerates. Strong reducing acids, hydrochloric in particular, are outside the range of the grade. Where any of that describes the service, a duplex, super duplex or nickel alloy is the right answer. ## A182 F316L forged products Forged to drawing or specification. Not held as catalogue stock. Minimum order one piece. | Product form | Also called | Size range | Single-piece weight | |---|---|---|---| | Forged bar | Round, square, flat, rectangular, hex bar | 80 to 1200 mm dia. or across flats, up to 8000 mm long | 20 to 20,000 kg | | Hollow forgings | Hollow bar, sleeve, bush, bushing, cylinder, barrel, casing, shell, hub, housing | 150 to 2500 mm OD, 50 to 2000 mm ID | up to 20,000 kg | | Seamless rolled rings | Radial-axial rolled rings | 200 to 3000 mm OD, height up to 1000 mm | up to 15,000 kg | | Forged rings | Mandrel-forged and punched rings | 200 to 3000 mm OD | up to 20,000 kg | | Discs, blocks and plates | Forged disc, disk, block, slab, tube sheet | 200 to 2500 mm dia., or to drawing | up to 20,000 kg | | Shafts | Gear shaft, pinion shaft, spindle, stepped shaft, eccentric shaft | up to 8000 mm long | up to 20,000 kg | | Forged flanges | Weld-neck, slip-on, blind, custom profile | 100 to 3000 mm OD | up to 10,000 kg | | Valve components | Bodies, bonnets, seat rings, stems, plugs, blocks | To drawing | To drawing | Size ranges describe the open-die and ring-rolling capability of the works across grades. What is achievable in F316L also depends on forging ratio, quench access for the section and the testing regime. ## Where A182 F316L is used - Chemical and petrochemical plant: pressure vessel forgings, nozzles, heat exchanger components, piping flanges and fittings - Valves: bodies, bonnets, seat rings, stems and plugs for ball, gate, globe, check and plug valves - Oil and gas, offshore and subsea: flanges, hubs, connectors, manifold parts - Pulp and paper: digester and liquor tank components, paper machine parts - Food, beverage and pharmaceutical: process equipment and storage - Heat exchangers: tube sheets, baffle rings, shell flanges, channel covers - Water treatment and desalination: pump and valve forgings - General engineering: shafts, spindles, sleeves, gear blanks, rings Suitability for a particular pressure code, whether ASME, PED or GB 150, depends on the approvals held for the grade and for the manufacturer, not on the analysis alone. ## Testing, inspection and certification | Test | Standard or method | When it applies | |---|---|---| | Chemical analysis | Spectrographic, per heat | Every order | | Tensile and yield | ASTM A182 acceptance | Every order | | Hardness | Brinell, reported as measured | Every order | | Ultrasonic examination | ASTM A388, EN 10228-3, SEP 1921 | On request or where specified | | Liquid penetrant examination | Customer procedure | On request | | Intergranular corrosion | ASTM A262 | On request | | Positive material identification | Portable spectrometry | On request | | Impact testing | Charpy V-notch, including cryogenic | On request | | Certification | EN 10204 3.1 standard, 3.2 third-party on request | Every order | Magnetic particle examination does not work on solution-annealed F316L, which is effectively non-magnetic. Liquid penetrant is the correct substitute. ## How an A182 F316L forging is made 1. **Drawing review and quotation.** Forgeability, ruling section, machining allowance, quench access and testing regime checked before pricing. 2. **Steel making and material certification.** Melt sourced to the required analysis, certificate traceable to heat number. Electric arc furnace with AOD or VOD refining is the normal route, with ESR where a specification calls for it. 3. **Heating and open-die forging.** Billet soaked to 1150 to 1200 C, then upset and drawn under open dies. 4. **Ring rolling.** Pierced blanks rolled radially and axially to final proportions. 5. **Solution treatment and quench.** Reheat to 1040 C minimum, soak, quench rapidly through the sensitising range. 6. **Pickling and passivation.** Where the order calls for it. 7. **Testing and inspection.** Chemistry, mechanical testing, hardness, dimensional check, plus ultrasonic, penetrant, A262 or PMI where specified. 8. **Machining.** Rough or finish machining to drawing. 9. **Documentation and despatch.** Certificates issued against the heat, parts marked to ASTM A182, packed and shipped. ## Questions **What is the UNS number for A182 F316L?** S31603. F316L is the grade symbol used inside ASTM A182, S31603 is the UNS number printed on the mill certificate. **What is the difference between A182 F316L and 316L?** 316L names the alloy. A182 F316L names a forged or rolled product made and certified to ASTM A182, which also fixes the heat-treated condition, mechanical acceptance, testing and marking. **What are the mechanical properties of A182 F316L?** ASTM A182 requires a minimum of 70 ksi [485 MPa] tensile strength, 25 ksi [170 MPa] yield strength, 30 % elongation and 50 % reduction of area. For sections over 5 in. [130 mm] the tensile minimum is 65 ksi [450 MPa]. **Is A182 F316L magnetic?** Effectively no, as solution annealed. Cold work and heavy machining can raise permeability at the worked surface, which catches out people checking an incoming forging with a pocket magnet. **Can A182 F316L be hardened by heat treatment?** No. Cold work is the only strengthening route. Where a corrosion-resistant forging has to be stronger, look at F316LN, duplex F51 or F53, or 17-4PH. **Can A182 F316L be welded?** Yes, and the 0.030 % carbon limit exists for that reason. It is the grade to specify when a welded assembly cannot be solution annealed afterwards. **What is the maximum service temperature?** No single figure. Code allowable stresses for the L grade fall off faster than for F316 as temperature climbs, and long exposure in the 450 to 850 C range risks carbide precipitation even at 0.030 % carbon. For sustained elevated-temperature pressure duty most codes point to F316 or F316H. Take the limit from the code you design to. **Do you supply EN 10204 3.1 or 3.2 certificates?** 3.1 as standard with every order. For 3.2 we arrange third-party inspection through SGS, BV, TUV or Lloyd's Register. Flag it at enquiry stage so the witness points go into the schedule. **What is the minimum order quantity?** One piece. Open dies and a ring mill both work from a single billet. Repeat bar sizes get cheaper above roughly 500 kg. **How long does an A182 F316L forging take?** Rough-forged and solution-annealed parts usually run 25 to 35 days from order. Parts needing machining to drawing, A262 testing or witnessed inspection typically run 35 to 45 days. **Do you hold A182 F316L in stock?** No. Everything is forged to order. **What information is needed to quote?** A drawing or dimensioned sketch, the quantity, the product form, the machining allowance if rough-forged, the certificate type, and any additional testing such as ultrasonic, A262 or PMI. ## Other grades - [A182 F316](https://www.steelforgepieces.com/Stainless-Steel/A182-F316.html) - standard-carbon version, higher strength minima - [A182 F321](https://www.steelforgepieces.com/Stainless-Steel/A182-F321.html) - titanium-stabilised alternative - [A182 F51](https://www.steelforgepieces.com/Stainless-Steel/A182-F51.html) - duplex, roughly double the yield strength - [A182 F53](https://www.steelforgepieces.com/Stainless-Steel/A182-F53.html) - super duplex for seawater service - [A182 F55](https://www.steelforgepieces.com/Stainless-Steel/A182-F55.html) - super duplex, common on subsea drawings - [A182 F44](https://www.steelforgepieces.com/Stainless-Steel/A182-F44.html) - 6 % molybdenum austenitic - [904L](https://www.steelforgepieces.com/Stainless-Steel/904L.html) - sulphuric and phosphoric acid duty - [Incoloy 825](https://www.steelforgepieces.com/Nickel-Alloy/Incoloy-825.html) - beyond the range of stainless - [All stainless steel grades](https://www.steelforgepieces.com/Stainless-Steel/) ## Contact Jiangyin Jiangnan Metal Co., Ltd. No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China Telephone, WhatsApp and WeChat: +86 189 2135 9659 Email: sales@steelforgepieces.com Web: https://www.steelforgepieces.com/ --- Technical data on this page is compiled from the published requirements of ASTM A182 for Grade F316L and is given for guidance. It is not a warranty of properties. The certificate issued with each forging governs.