Steel 36CrB4
EN 36CrB4
36CrB4 (1.7077) is a boron-modified chromium steel with slightly higher carbon than 32CrB4, supplied within the EN 10083 alloy-steel family, where boron provides hardening depth without extra alloy content.
Reference datasheet — 36CrB4 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
36CrB4 tempers and conditions
36CrB4 is supplied in 9 conditions, soft to hard. +QT is the default FabDigit quotes; the values on this page are for it.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Standard wire-rod/bar condition for cold heading and cold extrusion of bolts before quench and temper. | 370 | 570 | 25 | 175 HB | — |
Annealed | Pick for easiest machining of bar stock before hardening. | 380 | 600 | 22 | 185 HB | 45 W/m·K |
Supplied with specified hardenability (Jominy band), for hardening | Order this when the fastener/shaft will be hardened by the part maker and a guaranteed Jominy hardenability band is needed; as-quenched hardness reaches ~52–56 HRC before tempering. | 400 | 620 | 20 | 54 HRC | 8 % IACS |
Hot rolled | Cheapest mill condition for bar/wire rod that will be re-annealed or hardened by the customer. | 500 | 780 | 16 | 21 HRC | 7.9 % IACS |
Spheroidize annealed and cold drawn | Choose for close-tolerance, bright cold-drawn wire/bar that still heads well but arrives dimensionally accurate. | 560 | 680 | 12 | 210 HB | — |
Cold drawn | Bright bar for machined parts where surface finish and straightness matter more than heading ductility. | 700 | 830 | 9 | 24 HRC | 7.8 % IACS |
+QT | Same heat treatment on heavier bar; strength drops with the reduced cooling rate of boron steel. | 700 | 950 | 15 | 29 HRC | 7.9 % IACS |
+QTDefault Quenched and tempered | Default engineering condition: oil/polymer quench from ~860 °C and temper ~540–620 °C for class 10.9 bolts and small shafts. | 850 | 1,050 | 13 | 33 HRC | — |
+QT high-strength temper | Low-temper condition for wear-loaded shafts, pins and high-strength (12.9-type) fasteners; watch hydrogen embrittlement when plating. | 1,100 | 1,300 | 10 | 42 HRC | — |
What is 36CrB4?
36CrB4 (1.7077) is a boron-modified chromium steel with slightly higher carbon than 32CrB4, supplied within the EN 10083 alloy-steel family, where boron provides hardening depth without extra alloy content. It is used for medium-strength quenched-and-tempered fasteners and shafts, available as wire, rod and bar in +AR, +A, +AC, +AC+C, +C, +H and several +QT conditions. Default +QT properties are 850 MPa yield, 1050 MPa tensile, 13 % elongation and 320 HB (33 HRC), with service kept below about 300 °C. Weldability is restricted and formability after hardening is low; 41Cr4 or 42CrMo4 are the usual non-boron substitutes. 36CrB4 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). 36CrB4 has a yield strength of 850 MPa (123 ksi) and a tensile strength of 1,050 MPa (152 ksi) — stronger than 88% of steel grades. Elongation at break is 13% and the elastic modulus is 210 GPa (30.5 Msi).
What is 36CrB4 used for?
- bolts
- shafts
- fasteners
Advantages
- High strength — 850 MPa (123 ksi), better than 88% of steel grades
Limitations
- Limited formability — 20/100, worse than 80% of steel grades
- Limited ductility — 13%, worse than 78% of steel grades
- Low fracture toughness — 60 MPa·√m (54.6 ksi·√in), worse than 78% of steel grades
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
36CrB4 properties
Typical room-temperature values for 36CrB4-+QT; bars are the position among steel grades.
Physical3
36CrB4 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).
Mechanical16
36CrB4 has a yield strength of 850 MPa (123 ksi) and a tensile strength of 1,050 MPa (152 ksi) — stronger than 88% of steel grades. Elongation at break is 13% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
36CrB4 is rated for continuous service to 300°C (572 °F). It conducts heat at 43 W/m·K (24.8 BTU/hr·ft·°F), better than 51% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
36CrB4 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of 36CrB4 takes about 29 MJ of energy and emits 2.1 kg of CO₂ — less than 53% of steel grades. Typical recycled content is 30%.
Manufacturability8
36CrB4's machinability is fair (45/100, worse than 65% of steel grades); weldability poor (30/100); formability poor (20/100).
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. 36CrB4 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 36CrB4
Is 36CrB4 easy to machine?
Machine in +A/+AC condition (≈60 % of 1212) with carbide tooling; after Q&T above 33 HRC reduce speeds ~30 % or finish-grind.
Can 36CrB4 be welded?
Restricted weldability (CE ≈ 0.6–0.7): preheat 200–300 °C, low-hydrogen consumables and post-weld temper; boron increases HAZ hardening and cracking risk.
Can 36CrB4 be formed, bent or molded?
Excellent cold heading and cold extrusion in +AC/+AC+C wire; hot forge 1100–850 °C, austenitize 850–880 °C, oil or polymer quench, temper 400–650 °C for the required class.
36CrB4 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 |
|---|---|---|
| CEN 10083-3 / EN 10263-4 | 0.33 – 0.38 | 0.36 |
| Simax for cold-heading quality | ≤ 0.3 | 0.2 |
| Mn | 0.6 – 0.9 | 0.75 |
| P | ≤ 0.03 | 0.02 |
| S0.035 max in some hot-rolled deliveries | ≤ 0.03 | 0.01 |
| Cr | 0.9 – 1.2 | 1.05 |
| Beffective boron; Ti or Al added to fix nitrogen | 8×10⁻⁴ – 0.01 | 0 |
| Titypical nitrogen-fixing addition, producer practice | ≤ 0.05 | 0.03 |
| Fe | balance |
What surface finishes work on 36CrB4?
No anodizing; use zinc or zinc-nickel electroplate (bake at 200 °C within 4 h above 1000 MPa), zinc-flake coatings, or phosphate-and-oil for cold-formed fasteners.
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 36CrB4 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.7077
How much does 36CrB4 cost?
36CrB4 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
36CrB4 — frequently asked
What is 36CrB4 used for?
36CrB4 is typically used for bolts, shafts and fasteners. In short: higher-carbon boron fastener steel; Q&T strength above 1000 MPa; restricted weldability.
What is the yield strength of 36CrB4?
36CrB4 has a typical yield strength of 850 MPa (123 ksi) and a tensile strength of 1,050 MPa (152 ksi) — stronger than 88% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is 36CrB4 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in +A/+AC condition (≈60 % of 1212) with carbide tooling; after Q&T above 33 HRC reduce speeds ~30 % or finish-grind.
Can 36CrB4 be welded?
Not readily — weldability is rated poor (30/100). Restricted weldability (CE ≈ 0.6–0.7): preheat 200–300 °C, low-hydrogen consumables and post-weld temper; boron increases HAZ hardening and cracking risk.
What surface finishes work on 36CrB4?
No anodizing; use zinc or zinc-nickel electroplate (bake at 200 °C within 4 h above 1000 MPa), zinc-flake coatings, or phosphate-and-oil for cold-formed fasteners.
Can 36CrB4 be formed, bent or molded?
Excellent cold heading and cold extrusion in +AC/+AC+C wire; hot forge 1100–850 °C, austenitize 850–880 °C, oil or polymer quench, temper 400–650 °C for the required class.
What is the maximum service temperature of 36CrB4?
36CrB4 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 36CrB4 cost?
36CrB4 is a budget-cost steel ($), 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 — Alloy steels — CEN (2006)
- EN 10263-4 Steel rod, bars and wire for cold heading and cold extrusion — Steels for quenching and tempering — CEN (2018)
- EN 10084 / EN 10277 (delivery conditions +A, +AC, +C, +H) — CEN (2018)
- 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)
- Boron-alloyed cold heading steel datasheets (Ovako, voestalpine, Saarstahl) — various steelmakers (2023)
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.