Stainless Steel 334
AISI/SAE 334 · UNS S33400
334 (UNS S33400) is a nitrogen-strengthened 18-18-2 non-magnetic austenitic stainless steel developed for high-strength, non-magnetic retaining ring applications, with Ti/Al additions that form tenacious surface oxides.
Reference datasheet — 334 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the Annealed condition
334 tempers and conditions
334 is supplied in 3 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault solution annealed (typically 1065–1175 °C, rapid cool) | Standard stocked condition for plate, sheet, bar, tube and fabricated furnace hardware; maximum ductility and best high-temperature stability. | 275 | 585 | 45 | 150 HB | — |
Cold drawn | Choose when tighter tolerance, straighter bar and higher room-temperature strength are needed for machined furnace fixtures and fasteners. | 550 | 760 | 25 | 18 HRC | 1.7 % IACS |
Quarter hard | Rarely stocked; used for springy strip and formed clips where extra room-temperature strength is wanted before a stress-relief. | 620 | 860 | 15 | 23 HRC | 1.7 % IACS |
Supply forms, finishes and certifications
Ways 334 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
HRAP | Hot Rolled, Annealed & Pickled | Surface finish |
What is 334?
334 (UNS S33400) is a nitrogen-strengthened 18-18-2 non-magnetic austenitic stainless steel developed for high-strength, non-magnetic retaining ring applications, with Ti/Al additions that form tenacious surface oxides. Annealed material gives 275 MPa yield, 585 MPa tensile, 45 % elongation and 150 HB (80 HRB), with a maximum service temperature of 1100 °C; it is supplied annealed, hot-rolled annealed and pickled, cold drawn and quarter hard. Machinability is poor (score 30) and weldability is only moderate (score 65), so joint design and heat input need care. It is a specialty grade with limited stock availability. 334 has a density of 7.94 g/cm³ (0.287 lb/in³), heavier than 78% of stainless steel grades. It melts at 1,345°C (2,453 °F). 334 has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 77% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 196 GPa (28.4 Msi).
What is 334 used for?
- Generator retaining rings
- Non-magnetic structural parts
- High-temperature furnace fixtures
- Heat-treatment baskets and trays
- Low-permeability instrument housings
- Hot ducting and support hardware
Advantages
- High service temperature — 1,100°C (2,012 °F), better than 96% of stainless steel grades
- Forms and bends easily — 70/100, better than 79% of stainless steel grades
- Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades
Limitations
- High embodied carbon — 8.5 kg CO₂/kg, worse than 99% of stainless steel grades
- Low electrical conductivity — 1.7 % IACS, worse than 93% of stainless steel grades
- Poor heat conductor — 12.5 W/m·K (7.22 BTU/hr·ft·°F), worse than 90% of stainless steel grades
- Low strength — 275 MPa (39.9 ksi), worse than 77% of stainless steel grades
334 properties
Typical room-temperature values for 334-Annealed; bars are the position among stainless steel grades.
Physical3
334 has a density of 7.94 g/cm³ (0.287 lb/in³), heavier than 78% of stainless steel grades. It melts at 1,345°C (2,453 °F).
Mechanical13
334 has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 77% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 196 GPa (28.4 Msi).
Thermal6
334 is rated for continuous service to 1,100°C (2,012 °F). It conducts heat at 12.5 W/m·K (7.22 BTU/hr·ft·°F), worse than 90% of stainless steel grades. Thermal expansion is 14.4 µm/m·K (8 µin/in·°F).
Electrical3
334 conducts electricity at 1.7 % IACS, worse than 93% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 52% of stainless steel grades.
Sustainability4
Producing a kilogram of 334 takes about 85 MJ of energy and emits 8.5 kg of CO₂ — more than 92% of stainless steel grades. Typical recycled content is 40%.
Manufacturability6
334's machinability is poor (30/100, worse than 70% of stainless steel grades); weldability good (65/100); formability very good (70/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. 334 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 334
Is 334 easy to machine?
Gummy and strongly work-hardening — use rigid setups, positive-rake carbide, heavy feeds with no dwell, low-to-moderate speed (~25–40 m/min) and flood sulphochlorinated coolant.
Can 334 be welded?
Weld with GTAW/GMAW using matching 334/330 or Ni-base (ERNiCr-3) filler, low heat input and no preheat; avoid heavy restraint to limit hot cracking and avoid 650–870 °C exposure that embrittles the HAZ.
Can 334 be formed, bent or molded?
Formable hot (1050–1200 °C) or cold, but cold work demands 40–50 % more power than 304 and generous bend radii plus intermediate solution anneals.
334 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C | ≤ 0.08 | 0.05 |
| Mn | ≤ 1 | 0.7 |
| Siaids oxidation resistance | 0.75 – 1.5 | 1.1 |
| P | ≤ 0.04 | |
| S | ≤ 0.03 | |
| Cr | 18 – 20 | 19 |
| Ni | 34 – 37 | 35 |
| Tiscale adherence / carbide stabilisation | 0.15 – 0.6 | 0.35 |
| Alimproves oxide adherence | 0.15 – 0.6 | 0.35 |
| Fe | balance |
What surface finishes work on 334?
Pickle in HNO₃-HF then passivate in nitric acid to remove Ti/Al-rich oxides; polishes to a bright finish, no anodizing applicable, plating rarely used.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel 334 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- S33400
How much does 334 cost?
334 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
334 — frequently asked
What is 334 used for?
334 is typically used for generator retaining rings, non-magnetic structural parts, high-temperature furnace fixtures, heat-treatment baskets and trays, low-permeability instrument housings and hot ducting and support hardware. In short: non-magnetic retaining ring grade; 1100 °C service capability; specialty, limited availability.
What is the yield strength of 334?
334 has a typical yield strength of 275 MPa (39.9 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 77% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is 334 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 70% of stainless steel grades). Gummy and strongly work-hardening — use rigid setups, positive-rake carbide, heavy feeds with no dwell, low-to-moderate speed (~25–40 m/min) and flood sulphochlorinated coolant.
Can 334 be welded?
Yes — weldability is rated good (65/100). Weld with GTAW/GMAW using matching 334/330 or Ni-base (ERNiCr-3) filler, low heat input and no preheat; avoid heavy restraint to limit hot cracking and avoid 650–870 °C exposure that embrittles the HAZ.
What surface finishes work on 334?
Pickle in HNO₃-HF then passivate in nitric acid to remove Ti/Al-rich oxides; polishes to a bright finish, no anodizing applicable, plating rarely used.
Can 334 be formed, bent or molded?
Formable hot (1050–1200 °C) or cold, but cold work demands 40–50 % more power than 304 and generous bend radii plus intermediate solution anneals.
What is the maximum service temperature of 334?
334 is rated for continuous use to about 1,100°C (2,012 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 334 Annealed and 334-CD?
Annealed is the default condition — standard stocked condition for plate, sheet, bar, tube and fabricated furnace hardware; maximum ductility and best high-temperature stability. CD: choose when tighter tolerance, straighter bar and higher room-temperature strength are needed for machined furnace fixtures and fasteners. Yield strength is 275 MPa in Annealed versus 550 MPa in CD.
How much does 334 cost?
334 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- SAE J405 — Chemical Compositions of SAE Wrought Stainless Steels — SAE International (2013)
- Metals & Alloys in the Unified Numbering System (UNS S33400) — SAE/ASTM (2017)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Heat-resisting 19Cr-35Ni alloy (330/334) datasheet — Sandvik / Outokumpu (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.