Steel 94B15
EN 94B15 · UNS G94151
94B15 is a low-carbon, boron-modified case-hardening alloy steel (UNS G94151) from the SAE-AISI 94Bxx series, where a small boron addition raises hardenability so less nickel, chromium and molybdenum is needed.
Reference datasheet — 94B15 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 ANN condition
94B15 tempers and conditions
94B15 is supplied in 8 conditions, soft to hard. ANN 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 | Choose when parts (pins, bolts, gear blanks) are cold formed before carburizing. | 300 | 470 | 30 | 131 HB | 8 % IACS |
ANNDefault Annealed | Default supply condition for machining of blanks before carburizing. | 330 | 510 | 26 | 143 HB | — |
Hot rolled | Lowest-cost mill bar condition for parts that will be fully heat treated later. | 360 | 545 | 24 | 156 HB | 8 % IACS |
Normalized | Use to refine forging/rolling structure and give uniform response to later carburizing. | 400 | 590 | 24 | 174 HB | 8 % IACS |
Cold drawn | Pick for close-tolerance, straight bright bar with higher as-supplied strength. | 545 | 640 | 15 | 11 HRC | 8 % IACS |
quenched and tempered ~500 °C | Tough medium-hardness core condition for shafts and machined components. | 790 | 950 | 17 | 30 HRC | 8 % IACS |
Carburized, quenched and tempered | The intended service condition: hard wear-resistant case over a strong boron-hardened core for gears and pins. | 830 | 1,100 | 12 | 60 HRC | — |
Q&T | Direct-hardened condition for small boron-steel parts needing maximum core strength without carburizing. | 970 | 1,240 | 13 | 42 HRC | — |
What is 94B15?
94B15 is a low-carbon, boron-modified case-hardening alloy steel (UNS G94151) from the SAE-AISI 94Bxx series, where a small boron addition raises hardenability so less nickel, chromium and molybdenum is needed. It is chosen for carburized gears and pins that need a deep, hard case over a tough core at lower alloy cost, and is stocked as hot-rolled, annealed, normalized and cold-drawn bar. Annealed properties are 330 MPa yield, 510 MPa tensile, 26 % elongation and 143 HB, with a machinability score of 62. It has no inherent corrosion resistance and the boron hardenability gives a hard HAZ; 8620 is the usual alternative where welding or established carburizing practice matters more than alloy cost. 94B15 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). 94B15 has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 78% of steel grades. Elongation at break is 26% and the elastic modulus is 205 GPa (29.7 Msi).
What is 94B15 used for?
- carburized gears
- pins
- case-hardened components
Advantages
- 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
- Forms and bends easily — 70/100, better than 86% of steel grades
- Ductile — tolerates forming and impact — 26%, better than 82% of steel grades
Limitations
- Low strength — 330 MPa (47.9 ksi), worse than 78% of steel grades
94B15 properties
Typical room-temperature values for 94B15-ANN; bars are the position among steel grades.
Physical3
94B15 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).
Mechanical14
94B15 has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 78% of steel grades. Elongation at break is 26% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
94B15 is rated for continuous service to 400°C (752 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
94B15 conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 94B15 takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability6
94B15's machinability is good (62/100, better than 89% of steel grades); weldability good (62/100); formability very good (70/100).
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. 94B15 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 94B15
Is 94B15 easy to machine?
Machine in the annealed or normalized state (≈60–70 % of 1212) with sharp carbide tooling and generous coolant; leave grinding stock for post-carburizing distortion.
Can 94B15 be welded?
Weldable with low-hydrogen consumables, 150–250 °C preheat and post-weld temper; avoid welding after carburizing and expect hard HAZ from the boron hardenability.
Can 94B15 be formed, bent or molded?
Cold heading and upsetting are practical in the spheroidize-annealed condition; hot forge 1050–1200 °C but keep austenitizing below ~1050 °C to preserve boron hardenability.
94B15 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 | 0.13 – 0.18 | 0.16 |
| Mn | 0.75 – 1 | 0.88 |
| Si | 0.15 – 0.35 | 0.25 |
| Ni | 0.3 – 0.6 | 0.45 |
| Cr | 0.3 – 0.5 | 0.4 |
| Mo | 0.08 – 0.15 | 0.12 |
| Bboron-treated (B-suffix grade); effective boron requires N-fixing with Ti/Al | 5×10⁻⁴ – 0 | 0 |
| P | ≤ 0.04 | |
| S | ≤ 0.04 | |
| Fe | balance |
What surface finishes work on 94B15?
No inherent corrosion resistance — protect by oiling, phosphating, black oxide, zinc or nitrocarburizing; carburized surfaces are usually ground and shot peened for fatigue.
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 94B15 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- G94151
How much does 94B15 cost?
94B15 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.
94B15 — frequently asked
What is 94B15 used for?
94B15 is typically used for carburized gears, pins and case-hardened components. In short: low-cost carburizing steel; boron-boosted hardenability; deep case, tough core.
What is the yield strength of 94B15?
94B15 has a typical yield strength of 330 MPa (47.9 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 78% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 94B15 easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Machine in the annealed or normalized state (≈60–70 % of 1212) with sharp carbide tooling and generous coolant; leave grinding stock for post-carburizing distortion.
Can 94B15 be welded?
Yes — weldability is rated good (62/100). Weldable with low-hydrogen consumables, 150–250 °C preheat and post-weld temper; avoid welding after carburizing and expect hard HAZ from the boron hardenability.
What surface finishes work on 94B15?
No inherent corrosion resistance — protect by oiling, phosphating, black oxide, zinc or nitrocarburizing; carburized surfaces are usually ground and shot peened for fatigue.
Can 94B15 be formed, bent or molded?
Cold heading and upsetting are practical in the spheroidize-annealed condition; hot forge 1050–1200 °C but keep austenitizing below ~1050 °C to preserve boron hardenability.
What is the maximum service temperature of 94B15?
94B15 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 94B15-ANN and 94B15 QT-200?
ANN is the default condition — default supply condition for machining of blanks before carburizing. QT-200: direct-hardened condition for small boron-steel parts needing maximum core strength without carburizing. Yield strength is 330 MPa in ANN versus 970 MPa in QT-200.
How much does 94B15 cost?
94B15 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 Boron H-Steels — SAE International (2018)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (carburizing and boron steels) — ASM International (1991)
- Machinery's Handbook (machinability ratings) — 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.