Steel 86B45
EN 86B45 · UNS G86451
86B45 is a boron-treated Ni-Cr-Mo alloy steel (UNS G86451) whose hardenability approaches that of richer alloy grades at lower alloy content.
Reference datasheet — 86B45 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 QT32-36 condition
86B45 tempers and conditions
86B45 is supplied in 10 conditions, soft to hard. QT32-36 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 | Use for cold-headed fasteners and cold-extruded blanks where maximum ductility of the carbide structure is needed. | 390 | 620 | 26 | 9 HRC | 8.3 % IACS |
Solution annealed | Pick for maximum machinability and softness before quench-and-temper or cold forming. | 415 | 655 | 22 | 190 HB | 44 W/m·K |
Hot rolled | Cheapest mill condition for stock bar that will be machined then heat treated by the user. | 470 | 760 | 18 | 217 HB | — |
Normalized | Grain refinement and uniform structure ahead of machining or hardening; moderate strength forgings. | 550 | 830 | 17 | 23 HRC | — |
Cold drawn | Choose for tight-tolerance, good-surface bar used as-supplied for shafts and screw-machine parts. | 680 | 790 | 12 | 235 HB | — |
Q&T 28–32 HRC | Tough general-purpose condition for shafts, couplings and machined parts needing good impact resistance. | 840 | 965 | 18 | 30 HRC | — |
QT32-36Default Q&T 32–36 HRC | Standard stocked strength/toughness balance for gear blanks, drive shafts and high-strength fasteners. | 950 | 1,080 | 16 | 34 HRC | — |
Induction hardened | Choose for journal, spline and gear-tooth wear surfaces needing a hard case with a tough tempered core. | 950 | 1,080 | 14 | 57 HRC | 7.3 % IACS |
Q&T 38–42 HRC | Higher-strength condition for heavily loaded shafts, pins and links where some toughness can be traded for strength. | 1,180 | 1,310 | 13 | 40 HRC | — |
Q&T 44–48 HRC | Maximum through-hardened strength/wear condition; use only where notch sensitivity and hydrogen embrittlement are controlled. | 1,400 | 1,550 | 10 | 46 HRC | — |
What is 86B45?
86B45 is a boron-treated Ni-Cr-Mo alloy steel (UNS G86451) whose hardenability approaches that of richer alloy grades at lower alloy content. In the default quenched-and-tempered condition it provides 950 MPa yield, 1080 MPa tensile and 16 % elongation at 320 HB (34 HRC), and is available hot-rolled, annealed, spheroidized, normalized, cold-drawn, Q&T from 28 to 48 HRC and induction-hardened. Weldability is poor with a carbon equivalent of about 0.8–0.9, service temperature is capped at 400 °C, and machinability is 42 — the lowest of the boron grades listed here. Standard 8645 or 4340 are the closest non-boron alternatives. 86B45 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). 86B45 has a yield strength of 950 MPa (138 ksi) and a tensile strength of 1,080 MPa (157 ksi) — stronger than 91% of steel grades. Elongation at break is 16% and the elastic modulus is 205 GPa (29.7 Msi).
What is 86B45 used for?
- gears
- shafts
- high-strength bolts
Advantages
- High strength — 950 MPa (138 ksi), better than 91% of steel grades
Limitations
- Limited formability — 22/100, worse than 76% of steel grades
86B45 properties
Typical room-temperature values for 86B45-QT32-36; bars are the position among steel grades.
Physical3
86B45 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
86B45 has a yield strength of 950 MPa (138 ksi) and a tensile strength of 1,080 MPa (157 ksi) — stronger than 91% of steel grades. Elongation at break is 16% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
86B45 is rated for continuous service to 400°C (752 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
86B45 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 86B45 takes about 28 MJ of energy and emits 2.2 kg of CO₂ — less than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
86B45's machinability is fair (42/100, worse than 73% of steel grades); weldability poor (28/100); formability poor (22/100).
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. 86B45 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 86B45
Is 86B45 easy to machine?
Machine in the annealed/normalized state (~190–240 HB) with coated carbide; above 34 HRC use rigid setups, negative-rake carbide or CBN and reduced feeds.
Can 86B45 be welded?
Poor weldability (CE ≈ 0.8–0.9): preheat 250–350 °C, low-hydrogen consumables, and temper immediately after welding to avoid HAZ cracking.
Can 86B45 be formed, bent or molded?
Cold head or form only in the spheroidize-annealed condition; hot forge at 1050–1200 °C and normalize afterwards to restore grain size.
86B45 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 |
|---|---|---|
| CSAE 86B45 heat analysis | 0.43 – 0.48 | 0.46 |
| Mn | 0.75 – 1 | 0.88 |
| Si | 0.15 – 0.35 | 0.25 |
| Ni | 0.4 – 0.7 | 0.55 |
| Cr | 0.4 – 0.6 | 0.5 |
| Mo | 0.15 – 0.25 | 0.2 |
| Bboron addition for hardenability; requires Ti/Al nitrogen fixation | 5×10⁻⁴ – 0 | 0 |
| P | ≤ 0.04 | |
| S | ≤ 0.04 | |
| Fe | balance |
What surface finishes work on 86B45?
No anodizing — protect with zinc/manganese phosphate, black oxide, zinc or Cr plating; bake 190–220 °C for 4 h after plating when above 40 HRC.
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 86B45 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- G86451
How much does 86B45 cost?
86B45 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.
86B45 — frequently asked
What is 86B45 used for?
86B45 is typically used for gears, shafts and high-strength bolts. In short: alloy-grade hardenability, less nickel; high-strength shaft and gear steel; poor weldability, coat for corrosion.
What is the yield strength of 86B45?
86B45 has a typical yield strength of 950 MPa (138 ksi) and a tensile strength of 1,080 MPa (157 ksi) — stronger than 91% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 86B45 easy to machine?
Not especially — machinability is rated fair (42/100, worse than 73% of steel grades). Machine in the annealed/normalized state (~190–240 HB) with coated carbide; above 34 HRC use rigid setups, negative-rake carbide or CBN and reduced feeds.
Can 86B45 be welded?
Not readily — weldability is rated poor (28/100). Poor weldability (CE ≈ 0.8–0.9): preheat 250–350 °C, low-hydrogen consumables, and temper immediately after welding to avoid HAZ cracking.
What surface finishes work on 86B45?
No anodizing — protect with zinc/manganese phosphate, black oxide, zinc or Cr plating; bake 190–220 °C for 4 h after plating when above 40 HRC.
Can 86B45 be formed, bent or molded?
Cold head or form only in the spheroidize-annealed condition; hot forge at 1050–1200 °C and normalize afterwards to restore grain size.
What is the maximum service temperature of 86B45?
86B45 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 86B45 QT32-36 and 86B45-SA?
QT32-36 is the default condition — standard stocked strength/toughness balance for gear blanks, drive shafts and high-strength fasteners. SA: use for cold-headed fasteners and cold-extruded blanks where maximum ductility of the carbide structure is needed. Yield strength is 950 MPa in QT32-36 versus 390 MPa in SA.
How much does 86B45 cost?
86B45 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
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- SAE J1268 — Hardenability Bands for Carbon and Alloy H Steels (86B45H) — SAE International (2019)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM International (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4A — Steel Heat Treating Fundamentals and Processes — ASM International (2013)
- Machinery's Handbook, 31st ed. — Industrial Press (2020)
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.