Steel 36MnB4
EN 36MnB4
36MnB4 (1.5537) is a higher-carbon boron-manganese steel from the EN 10083 alloy steel family, with enough carbon and boron hardenability to reach property class 12.9 after quenching and tempering.
Reference datasheet — 36MnB4 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
36MnB4 tempers and conditions
36MnB4 is supplied in 8 conditions, soft to hard. +AC+C is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Softest condition with globular carbides — pick for severe multi-station cold heading/extrusion of bolt blanks before quench and temper. | 380 | 560 | 22 | 165 HB | — |
Normalized | Used to refine grain and homogenize hot-rolled bar before machining or subsequent hardening; not a cold-heading condition. | 430 | 700 | 18 | 205 HB | — |
Specified hardenability (Jominy band), as-rolled delivery | Choose when the fastener/part maker needs a guaranteed Jominy hardenability band for through-hardening of thick sections; delivered hot-rolled/untreated unless combined with +AC. | 460 | 730 | 16 | 215 HB | — |
+AC+CDefault Spheroidize annealed and cold drawn | Standard fastener wire/bar delivery: spheroidized then lightly cold drawn to size, straightness and surface for cold heading or bar turning. | 500 | 640 | 12 | 190 HB | — |
Cold drawn | Plain cold-drawn bar for machined parts where good size tolerance and surface matter and the part will be hardened afterwards. | 650 | 780 | 9 | 235 HB | — |
Q&T to property class 10.9 | Tempered high (≈500–560 °C) for 10.9 bolts — best balance of strength, toughness and hydrogen-embrittlement safety. | 950 | 1,060 | 12 | 34 HRC | — |
Quenched and tempered | Standard through-hardened bar condition for high-strength shafts, pins and machined fasteners; specify section size, hardenability falls off above ~25 mm. | 980 | 1,200 | 11 | 38 HRC | — |
Q&T to property class 12.9 | Peak-strength condition for 12.9 socket-head cap screws; tempered ≈400–450 °C — highest load capacity but most sensitive to hydrogen embrittlement and notches. | 1,140 | 1,280 | 9 | 41 HRC | — |
What is 36MnB4?
36MnB4 (1.5537) is a higher-carbon boron-manganese steel from the EN 10083 alloy steel family, with enough carbon and boron hardenability to reach property class 12.9 after quenching and tempering. It is bought as cold heading quality wire, coil and bar for high-strength fasteners formed cold and heat treated afterwards. In the spheroidized default condition it shows 500 MPa yield, 640 MPa tensile, 12 % elongation and 190 HB (91 HRB); formability is good but weldability is poor (score 30) and there is no corrosion resistance. Choose 30MnB4 or 27MnB4 where class 10.9 is sufficient. 36MnB4 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). 36MnB4 has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 640 MPa (92.8 ksi) — stronger than 63% of steel grades. Elongation at break is 12% and the elastic modulus is 210 GPa (30.5 Msi).
What is 36MnB4 used for?
- Property class 12.9 bolts
- Socket head cap screws
- High-strength studs and threaded rod
- Cold-headed engine fasteners
- Wheel bolts
- Cold-forged pins and sleeves
Advantages
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- Forms and bends easily — 65/100, better than 81% of steel grades
Limitations
- Limited ductility — 12%, worse than 84% of steel grades
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
36MnB4 properties
Typical room-temperature values for 36MnB4-+AC+C; bars are the position among steel grades.
Physical3
36MnB4 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical15
36MnB4 has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 640 MPa (92.8 ksi) — stronger than 63% of steel grades. Elongation at break is 12% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
36MnB4 is rated for continuous service to 300°C (572 °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
36MnB4 conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 36MnB4 takes about 24 MJ of energy and emits 1.9 kg of CO₂ — less than 97% of steel grades. Typical recycled content is 30%.
Manufacturability7
36MnB4's machinability is good (55/100, better than 62% of steel grades); weldability poor (30/100); 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. 36MnB4 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 36MnB4
Is 36MnB4 easy to machine?
Machine in +AC or +AC+C (about 60% of AISI 1212); after Q&T above 38 HRC use carbide or CBN with rigid setups and expect heavy tool wear.
Can 36MnB4 be welded?
Poor — high hardenability from boron gives hard martensitic HAZ; if unavoidable use low-hydrogen consumables, 200–250 °C preheat and immediate post-weld temper.
Can 36MnB4 be formed, bent or molded?
Excellent multi-station cold heading and thread rolling in the spheroidized (+AC/+AC+C) condition with phosphate+soap or polymer lubricant; hot forge 1100–1200 °C, do not forge below ~850 °C.
36MnB4 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 | 0.32 – 0.39 | 0.36 |
| Si≤0.30 typical for cold-heading grades per EN 10263-4 | ≤ 0.4 | 0.25 |
| Mn | 0.8 – 1.1 | 0.95 |
| P | ≤ 0.03 | 0.02 |
| S≤0.025 for cold-heading wire (EN 10263-4) | ≤ 0.04 | 0.02 |
| Crresidual | ≤ 0.3 | 0.15 |
| Beffective boron; Ti/Al added to fix N | 8×10⁻⁴ – 0.01 | 0 |
| Tinitrogen fixing, producer practice | ≤ 0.05 | 0.04 |
| Fe | balance |
What surface finishes work on 36MnB4?
Not anodizable; use zinc or zinc-nickel plating with a 190–220 °C hydrogen bake within 4 h (or zinc-flake / Delta-type coatings on 12.9 parts to avoid embrittlement), black oxide + oil for indoor use.
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 36MnB4 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.5537
How much does 36MnB4 cost?
36MnB4 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
36MnB4 — frequently asked
What is 36MnB4 used for?
36MnB4 is typically used for property class 12.9 bolts, socket head cap screws, high-strength studs and threaded rod, cold-headed engine fasteners, wheel bolts and cold-forged pins and sleeves. In short: 12.9-capable boron steel; high carbon, deep hardening; poor weldability by design.
What is the yield strength of 36MnB4?
36MnB4 has a typical yield strength of 500 MPa (72.5 ksi) and a tensile strength of 640 MPa (92.8 ksi) — stronger than 63% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 36MnB4 easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machine in +AC or +AC+C (about 60% of AISI 1212); after Q&T above 38 HRC use carbide or CBN with rigid setups and expect heavy tool wear.
Can 36MnB4 be welded?
Not readily — weldability is rated poor (30/100). Poor — high hardenability from boron gives hard martensitic HAZ; if unavoidable use low-hydrogen consumables, 200–250 °C preheat and immediate post-weld temper.
What surface finishes work on 36MnB4?
Not anodizable; use zinc or zinc-nickel plating with a 190–220 °C hydrogen bake within 4 h (or zinc-flake / Delta-type coatings on 12.9 parts to avoid embrittlement), black oxide + oil for indoor use.
Can 36MnB4 be formed, bent or molded?
Excellent multi-station cold heading and thread rolling in the spheroidized (+AC/+AC+C) condition with phosphate+soap or polymer lubricant; hot forge 1100–1200 °C, do not forge below ~850 °C.
What is the maximum service temperature of 36MnB4?
36MnB4 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 36MnB4 cost?
36MnB4 is a budget-cost steel ($), 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 — Part 4: 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. 4: Heat Treating (boron hardenability) — ASM International (1991)
- Cold heading steel wire rod grade datasheets (boron steels 30MnB4/36MnB4) — 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.