Steel 8MnSi7
EN 8MnSi7
8MnSi7 (1.5113) is a low-carbon manganese-silicon steel used as the base chemistry for cold-formed and case-hardened fasteners, often before boron micro-alloying is added.
Reference datasheet — 8MnSi7 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 +U+C condition
8MnSi7 tempers and conditions
8MnSi7 is supplied in 6 conditions, soft to hard. +U+C is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Best cold-heading condition per EN 10263 when severe upsetting or thread rolling follows without intermediate anneal. | 240 | 395 | 32 | 116 HB | 9.3 % IACS |
Annealed | Pick when maximum ductility is needed before heavy multi-station cold heading or deep extrusion. | 255 | 410 | 29 | 122 HB | — |
Hot rolled | Cheapest mill condition for wire rod that will be pickled, drawn and annealed by the fastener maker. | 290 | 450 | 23 | 135 HB | — |
Light drawn | Small drafting for surface and size control while keeping most of the annealed ductility for cold heading. | 385 | 490 | 15 | 152 HB | 8 % IACS |
+U+CDefault Cold drawn from untreated hot rolled stock | Standard stocked bar/wire condition: tight tolerance, bright surface and raised yield strength for headers and screw machines. | 490 | 560 | 10 | 175 HB | — |
Carburized and hardened | Final condition for formed parts needing a wear-resistant hard case (0.1–0.5 mm) over a tough, low-carbon core. | 560 | 780 | 11 | 60 HRC | — |
What is 8MnSi7?
8MnSi7 (1.5113) is a low-carbon manganese-silicon steel used as the base chemistry for cold-formed and case-hardened fasteners, often before boron micro-alloying is added. In the default condition it shows about 490 MPa yield, 560 MPa tensile, 10 % elongation and 175 HB (88 HRB), and it is supplied mainly as cold-heading wire and drawn bar. Its strengths are cold formability (formability 65) and very good weldability at a carbon equivalent of roughly 0.35-0.40; the limits are modest core strength until case hardened, gummy machining in the annealed state and no corrosion resistance. Boron grades such as 20MnB4 are the usual alternative when higher hardenability is needed. 8MnSi7 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,490°C (2,714 °F). 8MnSi7 has a yield strength of 490 MPa (71.1 ksi) and a tensile strength of 560 MPa (81.2 ksi) — stronger than 61% of steel grades. Elongation at break is 10% and the elastic modulus is 207 GPa (30 Msi).
What is 8MnSi7 used for?
- fasteners
- cold-formed pins
- case-hardened small parts
Advantages
- Readily welded — 85/100, better than 83% of steel grades
- Forms and bends easily — 65/100, better than 81% of steel grades
Limitations
- Limited ductility — 10%, worse than 91% of steel grades
8MnSi7 properties
Typical room-temperature values for 8MnSi7-+U+C; bars are the position among steel grades.
Physical3
8MnSi7 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,490°C (2,714 °F).
Mechanical16
8MnSi7 has a yield strength of 490 MPa (71.1 ksi) and a tensile strength of 560 MPa (81.2 ksi) — stronger than 61% of steel grades. Elongation at break is 10% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
8MnSi7 is rated for continuous service to 350°C (662 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
8MnSi7 conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of 8MnSi7 takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability8
8MnSi7's machinability is good (58/100, better than 75% of steel grades); weldability excellent (85/100); 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 steel family
Yield strength against density for every steel grade FabDigit runs. 8MnSi7 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 8MnSi7
Is 8MnSi7 easy to machine?
Gummy in the annealed state — machine in the cold drawn (+C) condition, use sharp positive-rake tools, high speed and flood coolant to avoid built-up edge; expect ~60 % of AISI 1212.
Can 8MnSi7 be welded?
Very good with all arc processes (CE ≈ 0.35–0.40); no preheat needed for thin fastener sections, but avoid welding after case hardening.
Can 8MnSi7 be formed, bent or molded?
Designed for multi-station cold heading, extrusion and thread rolling; supply as +A/+AC with phosphate + soap or polymer lubricant, and use intermediate anneals for reductions above ~70 %.
8MnSi7 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 |
|---|---|---|
| Clow carbon for cold formability; per EN 10263-3 cold heading steel | ≤ 0.11 | 0.08 |
| Sisolid-solution strengthening; range varies by producer | 0.2 – 0.6 | 0.4 |
| Mndesignation figure 7 ⇒ ≈1.75 % Mn (Mn ×4 rule) | 1.4 – 1.8 | 1.65 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Altotal Al, grain refinement / N binding | ≥ 0.02 | 0.04 |
| N | ≤ 0.01 | |
| Fe | balance |
What surface finishes work on 8MnSi7?
Not anodizable; standard routes are zinc or zinc-nickel electroplating with baking, hot-dip galvanizing, zinc-flake coatings, or phosphate + oil; carburised parts must be plated with H-embrittlement relief bake.
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 8MnSi7 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.5113
How much does 8MnSi7 cost?
8MnSi7 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.
8MnSi7 — frequently asked
What is 8MnSi7 used for?
8MnSi7 is typically used for fasteners, cold-formed pins and case-hardened small parts. In short: cold-heading fastener base steel; very good weldability, CE 0.35-0.40; case-hardening chemistry.
What is the yield strength of 8MnSi7?
8MnSi7 has a typical yield strength of 490 MPa (71.1 ksi) and a tensile strength of 560 MPa (81.2 ksi) — stronger than 61% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is 8MnSi7 easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Gummy in the annealed state — machine in the cold drawn (+C) condition, use sharp positive-rake tools, high speed and flood coolant to avoid built-up edge; expect ~60 % of AISI 1212.
Can 8MnSi7 be welded?
Yes — weldability is rated excellent (85/100). Very good with all arc processes (CE ≈ 0.35–0.40); no preheat needed for thin fastener sections, but avoid welding after case hardening.
What surface finishes work on 8MnSi7?
Not anodizable; standard routes are zinc or zinc-nickel electroplating with baking, hot-dip galvanizing, zinc-flake coatings, or phosphate + oil; carburised parts must be plated with H-embrittlement relief bake.
Can 8MnSi7 be formed, bent or molded?
Designed for multi-station cold heading, extrusion and thread rolling; supply as +A/+AC with phosphate + soap or polymer lubricant, and use intermediate anneals for reductions above ~70 %.
What is the maximum service temperature of 8MnSi7?
8MnSi7 is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 8MnSi7 +U+C and 8MnSi7-CH?
+U+C is the default condition — standard stocked bar/wire condition: tight tolerance, bright surface and raised yield strength for headers and screw machines. CH: final condition for formed parts needing a wear-resistant hard case (0.1–0.5 mm) over a tough, low-carbon core. Yield strength is 490 MPa in +U+C versus 560 MPa in CH.
How much does 8MnSi7 cost?
8MnSi7 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
- EN 10263-3 Steel rod, bars and wire for cold heading and cold extrusion — Case hardening steels — CEN (2017)
- EN 10263-1/-2 Cold heading and cold extrusion steels — technical delivery conditions (+U, +A, +AC, +C, +LC) — CEN (2017)
- DIN 1654-3 Cold heading and cold extruding steels — case hardening steels (historical, 8MnSi7) — DIN (1989)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Stahlschlüssel (Key to Steel) — material no. 1.5113 — Verlag Stahlschlüssel Wegst (2019)
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.