Steel 17MnB4
EN 17MnB4
17MnB4 (1.5520) is a low-carbon manganese-boron steel from the EN 10083/10084 family, supplied mainly as cold-heading wire rod where boron provides hardenability at low alloy content.
Reference datasheet — 17MnB4 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 +AC+C condition
17MnB4 tempers and conditions
17MnB4 is supplied in 5 conditions, soft to hard. +AC+C 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 |
|---|---|---|---|---|---|---|
Spheroidize annealed | Softest condition, maximum reduction of area — choose for severe multi-station cold heading and deep extrusion. | 300 | 450 | 27 | 130 HB | — |
Hot rolled | Mill as-rolled coil/bar — the cheapest starting stock, drawn or annealed by the fastener maker before heading. | 350 | 530 | 22 | 155 HB | — |
+AC+CDefault Spheroidize annealed and cold drawn | Standard cold-heading wire delivery: soft spheroidized structure plus drawn size and surface — the default stock for bolt and screw makers. | 450 | 540 | 12 | 160 HB | — |
Cold drawn from as-rolled stock | Straight cold-drawn bar/wire with clean surface and tight tolerance for light heading, machining or straight-length parts. | 540 | 620 | 10 | 185 HB | — |
Hardenability-controlled (Jominy) / quenched and tempered fastener… | Ordered with guaranteed Jominy band (J1.5 ≈ 40–48 HRC) and used after water/oil quench + temper for property-class 8.8–10.9 fasteners. | 740 | 900 | 14 | 29 HRC | 43 W/m·K |
What is 17MnB4?
17MnB4 (1.5520) is a low-carbon manganese-boron steel from the EN 10083/10084 family, supplied mainly as cold-heading wire rod where boron provides hardenability at low alloy content. Engineers choose it for cold-headed and case-hardened fasteners: formability is rated 85, and the annealed/drawn condition on file gives about 450 MPa yield, 540 MPa tensile, 12 % elongation and 160 HB (84 HRB). Rated strength only appears after heat treatment (+H), the maximum service temperature is about 350 °C, and the bare steel has no corrosion resistance. 22MnB4 is the usual alternative when higher tempered strength classes are required. 17MnB4 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). 17MnB4 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 540 MPa (78.3 ksi) — stronger than 52% of steel grades. Elongation at break is 12% and the elastic modulus is 210 GPa (30.5 Msi).
What is 17MnB4 used for?
- cold heading wire
- bolts grade 8.8
- case-hardened fasteners
Advantages
- Forms and bends easily — 85/100, better than 96% of steel grades
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- Easy to machine — 62/100, better than 89% of steel grades
Limitations
- Limited ductility — 12%, worse than 84% of steel grades
17MnB4 properties
Typical room-temperature values for 17MnB4-+AC+C; bars are the position among steel grades.
Physical3
17MnB4 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical15
17MnB4 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 540 MPa (78.3 ksi) — stronger than 52% of steel grades. Elongation at break is 12% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
17MnB4 is rated for continuous service to 350°C (662 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 66% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
17MnB4 conducts electricity at 8.6 % IACS, better than 66% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 17MnB4 takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
17MnB4's machinability is good (62/100, better than 89% of steel grades); weldability good (65/100); formability excellent (85/100).
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. 17MnB4 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 17MnB4
Is 17MnB4 easy to machine?
Machine in the +AC or +AC+C condition (≈65 % of AISI 1212); gummy chips in soft anneal — use sharp positive-rake tools and good chip breakers, and finish-machine before hardening.
Can 17MnB4 be welded?
Weldable with CE_IIW ≈ 0.40–0.45 using low-hydrogen consumables; preheat 100–150 °C on heavier sections and avoid welding hardened parts, which lose temper and can crack.
Can 17MnB4 be formed, bent or molded?
Excellent cold heading, thread rolling and extrusion in +AC/+AC+C with phosphate + soap or polymer lube; keep effective boron intact and avoid over-drawing before multi-blow heading.
17MnB4 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 | 0.15 – 0.2 | 0.17 |
| SiSi ≤ 0.30 (low-Si for cold heading) | ≤ 0.3 | 0.15 |
| Mn | 0.9 – 1.2 | 1.05 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Beffective boron; requires N fixing by Al/Ti | 8×10⁻⁴ – 0.01 | 0 |
| Altotal Al, for nitrogen fixing / grain refinement | ≥ 0.02 | 0.04 |
| Tioptional, added to protect boron from nitrogen | ≤ 0.05 | 0.03 |
| Crresidual | ≤ 0.3 | 0.1 |
| Niresidual | ≤ 0.3 | 0.08 |
| Curesidual | ≤ 0.25 | 0.1 |
| Fe | balance |
What surface finishes work on 17MnB4?
No natural corrosion resistance — zinc electroplate (with bake-out against hydrogen embrittlement above 320 HV), zinc-flake, phosphate + oil or hot-dip galvanizing per ISO 4042/ISO 10683.
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 17MnB4 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.5520
How much does 17MnB4 cost?
17MnB4 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
17MnB4 — frequently asked
What is 17MnB4 used for?
17MnB4 is typically used for cold heading wire, bolts grade 8.8 and case-hardened fasteners. In short: best formability of the MnB group; most weldable boron fastener steel; low-cost hardenable wire rod.
What is the yield strength of 17MnB4?
17MnB4 has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 540 MPa (78.3 ksi) — stronger than 52% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is 17MnB4 easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Machine in the +AC or +AC+C condition (≈65 % of AISI 1212); gummy chips in soft anneal — use sharp positive-rake tools and good chip breakers, and finish-machine before hardening.
Can 17MnB4 be welded?
Yes — weldability is rated good (65/100). Weldable with CE_IIW ≈ 0.40–0.45 using low-hydrogen consumables; preheat 100–150 °C on heavier sections and avoid welding hardened parts, which lose temper and can crack.
What surface finishes work on 17MnB4?
No natural corrosion resistance — zinc electroplate (with bake-out against hydrogen embrittlement above 320 HV), zinc-flake, phosphate + oil or hot-dip galvanizing per ISO 4042/ISO 10683.
Can 17MnB4 be formed, bent or molded?
Excellent cold heading, thread rolling and extrusion in +AC/+AC+C with phosphate + soap or polymer lube; keep effective boron intact and avoid over-drawing before multi-blow heading.
What is the maximum service temperature of 17MnB4?
17MnB4 is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 17MnB4 cost?
17MnB4 is a budget-cost steel ($), 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 10263-4 — Steel rod, bars and wire for cold heading and cold extrusion: Part 4, steels for quenching and tempering — CEN (2018)
- EN 10263-1 — General technical delivery conditions (delivery states +U, +A, +AC, +C, +AC+C, +H) — CEN (2018)
- ISO 898-1 — Mechanical properties of fasteners, property classes 8.8/9.8/10.9 — ISO (2013)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 4 — Heat Treating (boron hardenability, Jominy) — ASM International (1991)
- Cold-heading boron steel wire rod datasheets (17MnB4 / 20MnB4) — European wire rod producers (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.