Steel 8622
AISI/SAE 8622 · UNS G86220
8622 is a nickel-chromium-molybdenum case-hardening steel (AISI/SAE 8622, UNS G86220), a slightly higher-carbon version of the 8620 series that gives improved core strength while retaining good carburizing response.
Reference datasheet — 8622 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
8622 tempers and conditions
8622 is supplied in 8 conditions, soft to hard. A 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 |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Standard stocked condition for machining gear blanks before carburizing; softest and most stable. | 390 | 550 | 30 | 163 HB | — |
Hardenability-guaranteed (H-band) bar | Order H-grade when Jominy end-quench hardenability must be inside the SAE J1268 band for consistent gear distortion and core hardness. | 395 | 560 | 29 | 170 HB | 7.8 % IACS |
Hot rolled | Cheapest mill condition for parts that will be fully re-heat-treated (carburized) after rough machining. | 400 | 630 | 23 | 183 HB | — |
Normalized | Use to refine grain and homogenize forgings before carburizing; better toughness uniformity than as-rolled. | 400 | 660 | 26 | 11 HRC | 7.8 % IACS |
Cold drawn | Pick for close-tolerance, bright-finish bar going straight to light machining or as-carburized small shafts. | 600 | 700 | 15 | 207 HB | — |
oil quenched and tempered (through-hardened core) | Direct-hardened condition for shafts and fasteners needing uniform mid-strength without a case. | 800 | 950 | 17 | 30 HRC | — |
oil quenched, lower tempering temperature | Higher-strength through-hardened option for small sections where toughness can be traded for load capacity. | 930 | 1,080 | 15 | 34 HRC | — |
Carburized, quenched & tempered | The intended service condition: hard wear/pitting-resistant case over a tough 30–40 HRC core for gears and pinions. | 950 | 1,250 | 11 | 60 HRC | — |
What is 8622?
8622 is a nickel-chromium-molybdenum case-hardening steel (AISI/SAE 8622, UNS G86220), a slightly higher-carbon version of the 8620 series that gives improved core strength while retaining good carburizing response. It is used for gears, shafts and spline components and is available hot-rolled, annealed, normalized, cold-drawn, carburized, or quenched-and-tempered to 28–32 or 32–36 HRC, with a hardenability-controlled 8622H variant. Default-condition values are 390 MPa yield, 550 MPa tensile, 30 % elongation and 163 HB (85 HRB), with machinability 60 and formability 58. Cold bending is restricted in the cold-drawn temper and the steel has no corrosion resistance; 8620 is the nearest alternative where core strength is less critical. 8622 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). 8622 has a yield strength of 390 MPa (56.6 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 64% of steel grades. Elongation at break is 30% and the elastic modulus is 205 GPa (29.7 Msi).
What is 8622 used for?
- gears
- shafts
- spline components
Advantages
- Ductile — tolerates forming and impact — 30%, better than 93% of steel grades
8622 properties
Typical room-temperature values for 8622-A; bars are the position among steel grades.
Physical3
8622 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
8622 has a yield strength of 390 MPa (56.6 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 64% of steel grades. Elongation at break is 30% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
8622 is rated for continuous service to 400°C (752 °F). It conducts heat at 46 W/m·K (26.6 BTU/hr·ft·°F), better than 71% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
8622 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 8622 takes about 31 MJ of energy and emits 2.2 kg of CO₂ — more than 64% of steel grades. Typical recycled content is 30%.
Manufacturability7
8622's machinability is good (60/100, better than 83% of steel grades); weldability fair (50/100); formability good (58/100).
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. 8622 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 8622
Is 8622 easy to machine?
Machine in the annealed or normalized state (~65 % of 1212) with carbide at 120–180 m/min; leave 0.2–0.4 mm grind stock for post-carburize distortion.
Can 8622 be welded?
Weldable with low-hydrogen consumables and 150–250 °C preheat plus post-weld stress relief; never weld carburized surfaces.
Can 8622 be formed, bent or molded?
Good hot forgeability at 1150–1250 °C followed by normalizing; cold bending limited in the cold-drawn temper.
8622 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 J404 | 0.2 – 0.25 | 0.22 |
| Mn | 0.7 – 0.9 | 0.8 |
| 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 |
| P | ≤ 0.04 | |
| Smax; 8622 resulfurized versions run higher | ≤ 0.04 | |
| Fe | balance |
What surface finishes work on 8622?
No anodizing — protect with black oxide, manganese phosphate, zinc plating or oil; carburized cases grind and superfinish well for gear flanks.
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 8622 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- G86220
How much does 8622 cost?
8622 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.
8622 — frequently asked
What is 8622 used for?
8622 is typically used for gears, shafts and spline components. In short: stronger core than 8620; H-band grade available; gear and spline steel.
What is the yield strength of 8622?
8622 has a typical yield strength of 390 MPa (56.6 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 64% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 8622 easy to machine?
Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Machine in the annealed or normalized state (~65 % of 1212) with carbide at 120–180 m/min; leave 0.2–0.4 mm grind stock for post-carburize distortion.
Can 8622 be welded?
With care — weldability is rated fair (50/100). Weldable with low-hydrogen consumables and 150–250 °C preheat plus post-weld stress relief; never weld carburized surfaces.
What surface finishes work on 8622?
No anodizing — protect with black oxide, manganese phosphate, zinc plating or oil; carburized cases grind and superfinish well for gear flanks.
Can 8622 be formed, bent or molded?
Good hot forgeability at 1150–1250 °C followed by normalizing; cold bending limited in the cold-drawn temper.
What is the maximum service temperature of 8622?
8622 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 8622-A and 8622 CARB?
A is the default condition — standard stocked condition for machining gear blanks before carburizing; softest and most stable. CARB: the intended service condition: hard wear/pitting-resistant case over a tough 30–40 HRC core for gears and pinions. Yield strength is 390 MPa in A versus 950 MPa in CARB.
How much does 8622 cost?
8622 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 — SAE International (2019)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (Carburizing) — ASM International (1991)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
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.