Steel FeMn
ASTM A99 · GB FeMn78
FeMn is a ferromanganese master alloy, commonly specified as FeMn78 or to A99, charged into steel and cast iron melts to add manganese and to deoxidize and desulfurize.
Reference datasheet — FeMn 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 HC-FeMn78C8.0 condition
FeMn tempers and conditions
FeMn is supplied in 11 conditions, soft to hard. HC-FeMn78C8.0 is the default FabDigit quotes; the values on this page are for it.
- N-FeMn
- HC-FeMn78C8.0
- HC-FeMn74C7.5
- HC-FeMn68C7.0
- HC-FeMn64C7.0
- LC-FeMn82C0.7
- MC-FeMn78C2.0
- MC-FeMn82C1.5
- ULC-FeMn88C0.1
- LC-FeMn84C0.4
- LC-FeMn88C0.2
Compare all 11 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Nitrided ferromanganese | Use when nitrogen and manganese must be added together, e.g. N-alloyed stainless, duplex and high-strength steels. | 80 | 0 | 49 HRC | 0.9 % IACS | |
HC-FeMn78C8.0Default FeMn78C8.0 | Bulk workhorse for deoxidation/Mn alloying of carbon and low-alloy steels and cast iron where carbon pickup is acceptable. | 120 | 0 | 58 HRC | 1.4 % IACS | |
FeMn74C7.5 | Slightly lower Mn/C high-carbon grade, common where feedstock ore grade or price favours it. | 125 | 0 | 57 HRC | 1.5 % IACS | |
FeMn68C7.0 | The most traded Chinese HC grade (Mn 65 %) for ordinary carbon steel and foundry use. | 130 | 0 | 56 HRC | 1.6 % IACS | |
FeMn64C7.0 | Lowest-Mn standard HC grade; cheapest Mn units for low-spec steel and grey iron. | 135 | 0 | 55 HRC | 1.6 % IACS | |
FeMn82C0.7 | Intermediate grade bridging medium- and low-carbon ferromanganese. | 150 | 0 | 41 HRC | 1.3 % IACS | |
FeMn78C2.0 | Economical medium-carbon grade for general alloy steel ladle additions. | 160 | 0.5 | 51 HRC | 1.4 % IACS | |
FeMn82C1.5 | Choose when Mn must be added late with limited carbon pickup, e.g. medium-carbon and alloy structural steels. | 170 | 0.5 | 49 HRC | 1.3 % IACS | |
FeMn88C0.1 | Premium grade for ultra-low-carbon, stainless and high-purity steels; highest price per Mn unit. | 180 | 0.5 | 30 HRC | 1.2 % IACS | |
FeMn84C0.4 | Slightly cheaper low-carbon grade for low-C steels with a small carbon allowance. | 240 | 0.8 | 39 HRC | 1.3 % IACS | |
FeMn88C0.2 | For low-carbon, IF, stainless and electrical steels where carbon pickup must be minimal. | 260 | 1 | 36 HRC | 1.2 % IACS |
What is FeMn?
FeMn is a ferromanganese master alloy, commonly specified as FeMn78 or to A99, charged into steel and cast iron melts to add manganese and to deoxidize and desulfurize. Grades are selected by carbon level — high-carbon at 7.0–8.0 % C with 64–78 % Mn, medium-carbon at 1.5–2.0 % C, low-carbon at 0.2–0.7 % C, ultra-low-carbon at 0.1 % C and nitrided FeMn — and by size, from 10–50 mm lump to 1–3 mm granules, briquettes and cored wire. Density is about 7.1 g/cm³ and the melting point about 1240 °C. Hard and brittle, so machining, welding and forming do not apply; FeSi75 is the equivalent silicon addition. FeMn has a density of 7.1 g/cm³ (0.257 lb/in³), lighter than 99% of steel grades. It melts at 1,240°C (2,264 °F). FeMn has a tensile strength of 120 MPa (17.4 ksi), weaker than 100% of steel grades. Elongation at break is 0% and the elastic modulus is 180 GPa (26.1 Msi).
What is FeMn used for?
- Steelmaking deoxidizer/desulfurizer
- Alloy steel manganese addition
- Cast iron alloying
- Welding flux component
Limitations
- Limited ductility — 0%, worse than 100% of steel grades
- Low fracture toughness — 3 MPa·√m (2.73 ksi·√in), worse than 100% of steel grades
- Poor heat conductor — 9 W/m·K (5.2 BTU/hr·ft·°F), worse than 100% of steel grades
- Low electrical conductivity — 1.4 % IACS, worse than 100% of steel grades
- Difficult to machine — 5/100, worse than 100% of steel grades
FeMn properties
Typical room-temperature values for FeMn-HC-FeMn78C8.0; bars are the position among steel grades.
Physical3
FeMn has a density of 7.1 g/cm³ (0.257 lb/in³), lighter than 99% of steel grades. It melts at 1,240°C (2,264 °F).
Mechanical10
FeMn has a tensile strength of 120 MPa (17.4 ksi), weaker than 100% of steel grades. Elongation at break is 0% and the elastic modulus is 180 GPa (26.1 Msi).
Thermal4
FeMn is rated for continuous service to 400°C (752 °F). It conducts heat at 9 W/m·K (5.2 BTU/hr·ft·°F), worse than 100% of steel grades. Thermal expansion is 17 µm/m·K (9.44 µin/in·°F).
Electrical3
FeMn conducts electricity at 1.4 % IACS, worse than 100% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (6/100), worse than 100% of steel grades.
Sustainability4
Producing a kilogram of FeMn takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 5%.
Manufacturability4
FeMn's machinability is not recommended (5/100, worse than 100% of steel grades); weldability not recommended (5/100); formability not recommended (2/100).
Common Calculations4
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 steel family
Yield strength against density for every steel grade FabDigit runs. FeMn is highlighted; hover a dot for its name, or open the interactive family chart.
Working with FeMn
Is FeMn easy to machine?
Not machined — hard and brittle; supplied crushed and screened (typically 10–50 mm lump, or 1–3 mm granules/powder for cored wire and briquettes).
Can FeMn be welded?
Not weldable; it is a melt addition, charged to the EAF/converter or added to the ladle stream, with Mn recovery typically 85–95 %.
Can FeMn be formed, bent or molded?
No cold or hot forming; product forms are cast/crushed lump, granules, briquettes and cored wire fill.
FeMn 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 |
|---|---|---|
| MnFeMn78C8.0 per GB/T 3795 / ASTM A99 high-carbon class | 75 – 82 | 78 |
| Chigh-carbon class | ≤ 8 | 7 |
| Sisub-grades at ≤1.0 / ≤1.5 / ≤2.0 | ≤ 2 | 1 |
| PP classes typically ≤0.20 / ≤0.25 / ≤0.33 / ≤0.38 | ≤ 0.33 | 0.2 |
| S | ≤ 0.03 | 0.02 |
| Fe | balance |
What surface finishes work on FeMn?
No surface finishing; keep dry and sealed to prevent oxidation and moisture-driven hydrogen/phosphine release from fines, and screen out dust before charging.
Surface treatments FabDigit runs on 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).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel FeMn in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- A99
- GB (China)
- FeMn78
- Other
- FMn78
How much does FeMn cost?
FeMn is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
FeMn — frequently asked
What is FeMn used for?
FeMn is typically used for steelmaking deoxidizer/desulfurizer, alloy steel manganese addition, cast iron alloying and welding flux component. In short: primary manganese melt addition; carbon-graded master alloy; not a machinable product.
What is the tensile strength of FeMn?
FeMn has a typical tensile strength of 120 MPa (17.4 ksi) — weaker than 100% of steel grades. Strength varies by condition: see the 11 listed tempers.
Is FeMn easy to machine?
Not especially — machinability is rated not recommended (5/100, worse than 100% of steel grades). Not machined — hard and brittle; supplied crushed and screened (typically 10–50 mm lump, or 1–3 mm granules/powder for cored wire and briquettes).
Can FeMn be welded?
Not readily — weldability is rated not recommended (5/100). Not weldable; it is a melt addition, charged to the EAF/converter or added to the ladle stream, with Mn recovery typically 85–95 %.
What surface finishes work on FeMn?
No surface finishing; keep dry and sealed to prevent oxidation and moisture-driven hydrogen/phosphine release from fines, and screen out dust before charging.
Can FeMn be formed, bent or molded?
No cold or hot forming; product forms are cast/crushed lump, granules, briquettes and cored wire fill.
What is the maximum service temperature of FeMn?
FeMn is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does FeMn cost?
FeMn is a budget-cost steel ($), cheaper than about 90% 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
- GB/T 3795 (Ferromanganese) — SAC / (2014)
- ASTM A99 Standard Specification for Ferromanganese — ASTM International (2018)
- ISO 5446 Ferromanganese — Specification and conditions of delivery — ISO (2017)
- ASM Handbook Vol. 1 — Steelmaking additions and ferroalloys — ASM International (1990)
- Manganese ferroalloy LCA data — International Manganese Institute (IMnI) (2022)
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.