Steel 27MnCrB5-2
EN 27MnCrB5-2
27MnCrB5-2 (1.7182) is a manganese-chromium-boron cold-heading and through-hardening steel supplied to the EN 10263 family as wire, rod and bar in +A, +AC, +N, +C, +Q and +QT conditions.
Reference datasheet — 27MnCrB5-2 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 +QT condition
27MnCrB5-2 tempers and conditions
27MnCrB5-2 is supplied in 10 conditions, soft to hard. +QT is the default FabDigit quotes; the values on this page are for it.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Standard wire-rod / drawn-wire condition for multi-station cold heading of bolts and screws. | 360 | 570 | 24 | 170 HB | 8 % IACS |
Annealed | Softest delivery state for machining, deep drawing and heavy cold upsetting of bar stock. | 400 | 620 | 22 | 190 HB | — |
Normalized | Uniform fine-grained structure for hot-formed bar before final machining or hardening. | 500 | 780 | 17 | 21 HRC | — |
Cold drawn | Drawn-to-size bar or wire with improved tolerance and surface; strength raised by cold work. | 660 | 780 | 10 | 21 HRC | 7.9 % IACS |
+QT | Heavier sections — mass effect lowers core strength; choose when section exceeds 40 mm. | 760 | 1,000 | 14 | 31 HRC | 7.8 % IACS |
+QT | Q&T properties for medium ruling sections where the boron effect still gives near-through hardening. | 870 | 1,100 | 13 | 35 HRC | 7.8 % IACS |
+QTDefault Quenched and tempered | Standard service condition for high-strength fasteners and small shafts up to 16 mm ruling section. | 980 | 1,200 | 12 | 38 HRC | — |
Q&T to bolt property class 10.9 | Cold-headed then Q&T fasteners tempered to 10.9 — the main commercial use of this grade. | 990 | 1,100 | 12 | 34 HRC | 7.8 % IACS |
Q&T to bolt property class 12.9 | Highest standard fastener class from this grade; watch hydrogen embrittlement — avoid electroplating or bake thoroughly. | 1,150 | 1,280 | 10 | 41 HRC | 7.5 % IACS |
Hardened | Intermediate state only — maximum hardness for the carbon level; must be tempered before service. | 1,250 | 1,600 | 4 | 48 HRC | 6.7 % IACS |
What is 27MnCrB5-2?
27MnCrB5-2 (1.7182) is a manganese-chromium-boron cold-heading and through-hardening steel supplied to the EN 10263 family as wire, rod and bar in +A, +AC, +N, +C, +Q and +QT conditions. It is used for property class 10.9 and 12.9 bolts and cold-headed fasteners, reaching 980 MPa yield, 1200 MPa tensile, 12 % elongation and 360 HB (38 HRC) after quench and temper. CEV of 0.6–0.7 makes it effectively non-weldable in service, hydrogen embrittlement is a risk above 1000 MPa, and service is limited to about 250 °C. 20MnB4 covers lower strength classes. 27MnCrB5-2 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). 27MnCrB5-2 has a yield strength of 980 MPa (142 ksi) and a tensile strength of 1,200 MPa (174 ksi) — stronger than 91% of steel grades. Elongation at break is 12% and the elastic modulus is 210 GPa (30.5 Msi).
What is 27MnCrB5-2 used for?
- high-strength bolts
- cold-headed fasteners
- screws
Advantages
- High strength — 980 MPa (142 ksi), better than 91% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
- Limited ductility — 12%, worse than 84% of steel grades
27MnCrB5-2 properties
Typical room-temperature values for 27MnCrB5-2-+QT; bars are the position among steel grades.
Physical3
27MnCrB5-2 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).
Mechanical16
27MnCrB5-2 has a yield strength of 980 MPa (142 ksi) and a tensile strength of 1,200 MPa (174 ksi) — stronger than 91% of steel grades. Elongation at break is 12% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
27MnCrB5-2 is rated for continuous service to 250°C (482 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 11.8 µm/m·K (6.56 µin/in·°F).
Electrical3
27MnCrB5-2 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 27MnCrB5-2 takes about 27 MJ of energy and emits 2.1 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 25%.
Manufacturability7
27MnCrB5-2's machinability is fair (42/100, worse than 73% of steel grades); weldability fair (35/100); formability poor (25/100).
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. 27MnCrB5-2 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 27MnCrB5-2
Is 27MnCrB5-2 easy to machine?
Machine in +A/+AC (≈190 HB) with carbide at moderate speeds; after Q&T to 35–41 HRC use coated carbide/CBN, rigid setups and grinding for finish features.
Can 27MnCrB5-2 be welded?
CEV ≈ 0.6–0.7, so preheat 200–300 °C, low-hydrogen consumables and post-weld tempering are required; boron promotes HAZ hardening and cold cracking — welding is generally avoided on finished fasteners.
Can 27MnCrB5-2 be formed, bent or molded?
Excellent multi-station cold heading and cold extrusion in spheroidize-annealed condition; hot forming 1050–1150 °C, austenitize 860–900 °C, oil/polymer quench, temper 400–560 °C avoiding the 250–400 °C temper-brittleness window.
27MnCrB5-2 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 | 0.24 – 0.3 | 0.27 |
| Simax only | ≤ 0.4 | 0.25 |
| Mn | 1.1 – 1.4 | 1.25 |
| P | ≤ 0.03 | 0.02 |
| Smax; lower for cold-heading quality | ≤ 0.04 | 0.02 |
| Cr | 0.3 – 0.6 | 0.45 |
| Beffective (soluble) boron; Ti/Al additions used to tie up free nitrogen | 8×10⁻⁴ – 0.01 | 0 |
| Fe | balance |
What surface finishes work on 27MnCrB5-2?
Not anodizable — protect with zinc or zinc-nickel electroplate (bake 200 °C/4 h against hydrogen embrittlement above 1000 MPa), zinc-flake coating, phosphate + oil, or paint; nitriding or induction hardening can add surface wear resistance.
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 27MnCrB5-2 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.7182
How much does 27MnCrB5-2 cost?
27MnCrB5-2 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.
27MnCrB5-2 — frequently asked
What is 27MnCrB5-2 used for?
27MnCrB5-2 is typically used for high-strength bolts, cold-headed fasteners and screws. In short: through-hardening fastener steel; class 12.9 capable; boron replaces Cr-Mo alloying.
What is the yield strength of 27MnCrB5-2?
27MnCrB5-2 has a typical yield strength of 980 MPa (142 ksi) and a tensile strength of 1,200 MPa (174 ksi) — stronger than 91% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 27MnCrB5-2 easy to machine?
Not especially — machinability is rated fair (42/100, worse than 73% of steel grades). Machine in +A/+AC (≈190 HB) with carbide at moderate speeds; after Q&T to 35–41 HRC use coated carbide/CBN, rigid setups and grinding for finish features.
Can 27MnCrB5-2 be welded?
With care — weldability is rated fair (35/100). CEV ≈ 0.6–0.7, so preheat 200–300 °C, low-hydrogen consumables and post-weld tempering are required; boron promotes HAZ hardening and cold cracking — welding is generally avoided on finished fasteners.
What surface finishes work on 27MnCrB5-2?
Not anodizable — protect with zinc or zinc-nickel electroplate (bake 200 °C/4 h against hydrogen embrittlement above 1000 MPa), zinc-flake coating, phosphate + oil, or paint; nitriding or induction hardening can add surface wear resistance.
Can 27MnCrB5-2 be formed, bent or molded?
Excellent multi-station cold heading and cold extrusion in spheroidize-annealed condition; hot forming 1050–1150 °C, austenitize 860–900 °C, oil/polymer quench, temper 400–560 °C avoiding the 250–400 °C temper-brittleness window.
What is the maximum service temperature of 27MnCrB5-2?
27MnCrB5-2 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 27MnCrB5-2 cost?
27MnCrB5-2 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 10083-3 Steels for quenching and tempering — Part 3: Alloy steels — CEN (2006)
- EN 10263-4 Steel rod, bars and wire for cold heading and cold extrusion — quenched and tempered steels — CEN (2017)
- ISO 898-1 Mechanical properties of fasteners — bolts, screws and studs — ISO (2013)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.19: Fatigue and Fracture — ASM International (1996)
- EN ISO 18265 Metallic materials — Conversion of hardness values — CEN/ISO (2013)
- Boron steel 27MnCrB5-2 (1.7182) bar and wire rod datasheets — European long-products steelmakers (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.