Stainless Steel ER307
UNS S30780 · EN 18 8 Mn
ER307 is a Cr-Ni-Mn austenitic filler wire (UNS S30780, also designated 18 8 Mn) in which manganese stabilises the austenite and raises tolerance to dilution from crack-sensitive base metals.
Reference datasheet — ER307 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 AW condition
ER307 tempers and conditions
ER307 is supplied in 5 conditions, soft to hard. AW is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Submerged-arc deposit with neutral flux, as welded | Choose for heavy-wall joints and large-area overlay where submerged-arc deposition rate rules; the high heat input coarsens grain and trims strength to 600 MPa. | 380 | 600 | 35 | 185 HB | 2.2 % IACS |
TIG deposit, as welded | Pick for thin sheet, root passes and precision repair: the as-welded TIG deposit has low oxygen content, giving slightly higher toughness and 40% elongation. | 390 | 610 | 40 | 185 HB | 2.2 % IACS |
AWDefault As-welded deposit | Standard choice: gas-shielded all-weld metal evaluated as welded, for joints in dissimilar and hard-to-weld steels, with service to 850 °C and 38% elongation. | 400 | 620 | 38 | 190 HB | 2.2 % IACS |
MIG/MAG spool deposit, as welded | Use spooled wire under Ar+2%O₂ or Ar+CO₂ for efficient fill on medium and thick plate and for buffer layers under hardfacing, as welded at 630 MPa tensile. | 410 | 630 | 36 | 195 HB | 2.2 % IACS |
Work-hardened weld surface | Expect this state on wear overlays and manganese-steel repairs where peening or service impact work-hardens the bead above 300 HB, at the cost of ductility and machinability. | 600 | 800 | 15 | 34 HRC | 2.1 % IACS |
What is ER307?
ER307 is a Cr-Ni-Mn austenitic filler wire (UNS S30780, also designated 18 8 Mn) in which manganese stabilises the austenite and raises tolerance to dilution from crack-sensitive base metals. Supplied as solid wire and rod for GTAW, GMAW and submerged-arc welding, it is used for dissimilar-steel joints, manganese steel repairs and buffer layers, with as-welded deposits near 400 MPa yield, 620 MPa tensile and 38% elongation. The deposit is rated to 850 °C, but corrosion resistance is below 308L and machinability is low (score 30, 190 HB). Use ER309L when a stainless-to-carbon joint needs conventional ferrite control. ER307 has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,400°C (2,552 °F). ER307 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 57% of stainless steel grades. Elongation at break is 38% and the elastic modulus is 196 GPa (28.4 Msi).
What is ER307 used for?
- Dissimilar metal welding
- Manganese steel joints
- Crack-resistant repair welds
Advantages
- Readily welded — 92/100, better than 98% of stainless steel grades
- High service temperature — 850°C (1,562 °F), better than 80% of stainless steel grades
Limitations
- Hard to polish — 60/100, worse than 80% of stainless steel grades
ER307 properties
Typical room-temperature values for ER307-AW; bars are the position among stainless steel grades.
Physical3
ER307 has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
ER307 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 57% of stainless steel grades. Elongation at break is 38% and the elastic modulus is 196 GPa (28.4 Msi).
Thermal6
ER307 is rated for continuous service to 850°C (1,562 °F). It conducts heat at 15 W/m·K (8.67 BTU/hr·ft·°F), worse than 59% of stainless steel grades. Thermal expansion is 17.5 µm/m·K (9.72 µin/in·°F).
Electrical3
ER307 conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 62% of stainless steel grades.
Sustainability4
Producing a kilogram of ER307 takes about 56 MJ of energy and emits 4.6 kg of CO₂ — more than 59% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
ER307's machinability is poor (30/100, worse than 70% of stainless steel grades); weldability excellent (92/100); formability good (65/100).
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. ER307 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ER307
Is ER307 easy to machine?
The deposit work-hardens severely and rates only 30 on machinability; use keen-edged carbide with positive rake, low surface speed with heavy feed, a rigid setup and flood coolant. Avoid dwelling or rubbing cuts that glaze the surface.
Can ER307 be welded?
GTAW, GMAW and submerged arc all apply, with pure Ar or Ar+2%O₂ / Ar+CO₂ shielding; keep interpass temperature ≤150 °C and do not normally preheat. In dissimilar-steel work the deposit serves as a buffer or transition layer.
Can ER307 be formed, bent or molded?
Not a formed product; as a filler metal it is not bent or drawn by the user. As-welded beads are ductile (38% elongation) but strength climbs quickly after cold work.
ER307 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 |
|---|---|---|
| CAWS A5.9 ER307 | 0.04 – 0.14 | 0.09 |
| Cr | 19.5 – 22 | 20.5 |
| Ni | 8 – 10.7 | 9.3 |
| MnEN ISO 14343 Z 18 8 Mn type reaches 6-8% Mn | 3.3 – 4.75 | 4 |
| Mo | 0.5 – 1.5 | 1 |
| Si | 0.3 – 0.65 | 0.45 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Cu | ≤ 0.75 | |
| Fe | balance |
What surface finishes work on ER307?
Grind the weld, then pickle and passivate or electropolish to restore a corrosion-resistant surface. Anodising does not apply to stainless deposits.
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 ER307 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- S30780
- EN / DIN / Werkstoff-Nr.
- 18 8 Mn
How much does ER307 cost?
ER307 is a premium-cost stainless steel ($$$), cheaper than about 51% 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.
ER307 — frequently asked
What is ER307 used for?
ER307 is typically used for dissimilar metal welding, manganese steel joints and crack-resistant repair welds. In short: dissimilar-steel joining filler; manganese-alloyed crack resistance; 850 °C service rating.
What is the yield strength of ER307?
ER307 has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 57% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is ER307 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 70% of stainless steel grades). The deposit work-hardens severely and rates only 30 on machinability; use keen-edged carbide with positive rake, low surface speed with heavy feed, a rigid setup and flood coolant. Avoid dwelling or rubbing cuts that glaze the surface.
Can ER307 be welded?
Yes — weldability is rated excellent (92/100). GTAW, GMAW and submerged arc all apply, with pure Ar or Ar+2%O₂ / Ar+CO₂ shielding; keep interpass temperature ≤150 °C and do not normally preheat. In dissimilar-steel work the deposit serves as a buffer or transition layer.
What surface finishes work on ER307?
Grind the weld, then pickle and passivate or electropolish to restore a corrosion-resistant surface. Anodising does not apply to stainless deposits.
Can ER307 be formed, bent or molded?
Not a formed product; as a filler metal it is not bent or drawn by the user. As-welded beads are ductile (38% elongation) but strength climbs quickly after cold work.
What is the maximum service temperature of ER307?
ER307 is rated for continuous use to about 850°C (1,562 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between ER307-AW and ER307 AW-CW?
AW is the default condition — standard choice: gas-shielded all-weld metal evaluated as welded, for joints in dissimilar and hard-to-weld steels, with service to 850 °C and 38% elongation. AW-CW: expect this state on wear overlays and manganese-steel repairs where peening or service impact work-hardens the bead above 300 HB, at the cost of ductility and machinability. Yield strength is 400 MPa in AW versus 600 MPa in AW-CW.
How much does ER307 cost?
ER307 is a premium-cost stainless steel ($$$), cheaper than about 51% 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
- AWS A5.9/A5.9M Bare Stainless Steel Welding Electrodes and Rods — AWS (2017)
- EN ISO 14343 Welding consumables — Wire electrodes for arc welding of stainless and heat-resisting steels — ISO (2017)
- ASM Handbook Vol.6 Welding, Brazing and Soldering — ASM International (1993)
- ASM Handbook Vol.1 Properties and Selection: Irons, Steels — ASM International (1990)
- Stainless filler metal 307 / 18 8 Mn (2023)
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.