Steel 41B17
EN 41B17 · UNS G41171
41B17 is a low-carbon boron-added molybdenum alloy steel (UNS G41171) used as a lower-cost substitute for standard 41xx grades in carburized parts.
Reference datasheet — 41B17 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 A condition
41B17 tempers and conditions
41B17 is supplied in 7 conditions, soft to hard. A is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Standard supply condition for gear blanks and cold-headed parts prior to carburizing. | 315 | 480 | 30 | 143 HB | — |
Hot rolled | Cheapest stock form for parts that will be fully carburized or Q&T after machining. | 330 | 515 | 27 | 149 HB | — |
Normalized | Grain refinement and uniform structure before carburizing or for moderately loaded parts. | 360 | 560 | 27 | 163 HB | — |
Cold drawn | Choose for close-tolerance, good-surface bar in automatic screw machines; higher strength, lower ductility. | 505 | 590 | 15 | 174 HB | — |
Q&T 22-28 HRC | Direct quench-and-temper without carburizing for shafts and fasteners needing tough medium strength. | 660 | 830 | 18 | 25 HRC | — |
Carburized, quenched and tempered | Primary service condition: hard wear-resistant case with tough boron-hardened core for gears and sprockets. | 800 | 1,030 | 12 | 60 HRC | — |
Q&T 28-34 HRC | Higher-strength through-hardened condition for pins, links and drive components. | 830 | 1,000 | 15 | 31 HRC | — |
What is 41B17?
41B17 is a low-carbon boron-added molybdenum alloy steel (UNS G41171) used as a lower-cost substitute for standard 41xx grades in carburized parts. In the annealed condition it gives 315 MPa yield, 480 MPa tensile and 30 % elongation at 143 HB (78 HRB), with good cold-heading behaviour (formability 70) and machinability at about 65 % of AISI 1212; carburizing produces a 58–62 HRC case. Stock conditions include hot-rolled, annealed, normalized, cold-drawn, Q&T and carburized bar. It has no corrosion resistance, is limited to 400 °C service, and boron narrows the HAZ toughness window, so 4118 and 8620 remain the nearest non-boron alternatives. 41B17 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). 41B17 has a yield strength of 315 MPa (45.7 ksi) and a tensile strength of 480 MPa (69.6 ksi) — weaker than 82% of steel grades. Elongation at break is 30% and the elastic modulus is 205 GPa (29.7 Msi).
What is 41B17 used for?
- carburized gears
- shafts
- pins
Advantages
- Ductile — tolerates forming and impact — 30%, better than 93% 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
Limitations
- Low strength — 315 MPa (45.7 ksi), worse than 82% of steel grades
41B17 properties
Typical room-temperature values for 41B17-A; bars are the position among steel grades.
Physical3
41B17 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
41B17 has a yield strength of 315 MPa (45.7 ksi) and a tensile strength of 480 MPa (69.6 ksi) — weaker than 82% of steel grades. Elongation at break is 30% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
41B17 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 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
41B17 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 41B17 takes about 29 MJ of energy and emits 2.1 kg of CO₂ — less than 53% of steel grades. Typical recycled content is 30%.
Manufacturability7
41B17's machinability is good (62/100, better than 89% of steel grades); weldability good (60/100); 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. 41B17 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 41B17
Is 41B17 easy to machine?
Machines like 4118/8620 at ~65 % of AISI 1212; best in spheroidize-annealed 140–180 HB with carbide tooling, and finish-machine before carburizing since the 58–62 HRC case needs grinding.
Can 41B17 be welded?
Weldable in the annealed/normalized condition with low-hydrogen consumables and 150–250 °C preheat, but boron narrows the HAZ toughness window; never weld after carburizing.
Can 41B17 be formed, bent or molded?
Good cold-heading and upsetting behavior in spheroidized bar; hot forge 1150–1230 °C and normalize afterwards to restore fine grain and boron hardenability.
41B17 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 |
|---|---|---|
| Ccarburizing carbon level | 0.15 – 0.2 | 0.17 |
| Mn | 0.75 – 1 | 0.88 |
| Si | 0.15 – 0.35 | 0.25 |
| Cr | 0.45 – 0.65 | 0.55 |
| Mo | 0.08 – 0.15 | 0.12 |
| Beffective (soluble) boron; requires Ti/Al nitrogen fixing | 5×10⁻⁴ – 0 | 0 |
| P | ≤ 0.04 | |
| S | ≤ 0.04 | |
| Fe | balance |
What surface finishes work on 41B17?
Non-anodizable ferrous steel — protect with zinc or manganese phosphate, black oxide, zinc/zinc-nickel plating (bake to avoid hydrogen embrittlement) or oil; ground and honed for gear tooth surfaces.
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 41B17 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- G41171
How much does 41B17 cost?
41B17 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.
41B17 — frequently asked
What is 41B17 used for?
41B17 is typically used for carburized gears, shafts and pins. In short: low-cost 8620 alternative; carburizing boron steel; good cold-heading formability.
What is the yield strength of 41B17?
41B17 has a typical yield strength of 315 MPa (45.7 ksi) and a tensile strength of 480 MPa (69.6 ksi) — weaker than 82% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 41B17 easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Machines like 4118/8620 at ~65 % of AISI 1212; best in spheroidize-annealed 140–180 HB with carbide tooling, and finish-machine before carburizing since the 58–62 HRC case needs grinding.
Can 41B17 be welded?
Yes — weldability is rated good (60/100). Weldable in the annealed/normalized condition with low-hydrogen consumables and 150–250 °C preheat, but boron narrows the HAZ toughness window; never weld after carburizing.
What surface finishes work on 41B17?
Non-anodizable ferrous steel — protect with zinc or manganese phosphate, black oxide, zinc/zinc-nickel plating (bake to avoid hydrogen embrittlement) or oil; ground and honed for gear tooth surfaces.
Can 41B17 be formed, bent or molded?
Good cold-heading and upsetting behavior in spheroidized bar; hot forge 1150–1230 °C and normalize afterwards to restore fine grain and boron hardenability.
What is the maximum service temperature of 41B17?
41B17 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 41B17-A and 41B17 QT-32?
A is the default condition — standard supply condition for gear blanks and cold-headed parts prior to carburizing. QT-32: higher-strength through-hardened condition for pins, links and drive components. Yield strength is 315 MPa in A versus 830 MPa in QT-32.
How much does 41B17 cost?
41B17 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)
- 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 (boron hardenability, carburizing) — ASM International (2013)
- UNS G41171 alloy record — SAE/ASTM Unified Numbering System (2019)
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.