Steel 8622 QT-28-32HRC
Hardness band
AISI/SAE 8622 · UNS G86220
Direct-hardened condition for shafts and fasteners needing uniform mid-strength without a case.
Values for the QT-28-32HRC condition
Other 8622 tempers and conditions
8622 is listed in 8 conditions; see the grade overview at 8622.
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 | — |
QT-28-32HRCThis page 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 QT-28-32HRC?
8622 QT-28-32HRC is 8622 heat treated to QT-28-32HRC — direct-hardened condition for shafts and fasteners needing uniform mid-strength without a case. 8622 QT-28-32HRC has a yield strength of 800 MPa (116 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 86% of steel grades. Elongation at break is 17% and the elastic modulus is 205 GPa (29.7 Msi). 8622 QT-28-32HRC 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). A is the default condition FabDigit quotes; QT-28-32HRC is available on request or by drawing note.
Advantages
- High strength — 800 MPa (116 ksi), better than 86% of steel grades
8622 QT-28-32HRC properties
Typical room-temperature values for 8622 QT-28-32HRC; 14 are specific to this condition. Other listed values are 8622 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
8622 QT-28-32HRC 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 QT-28-32HRC has a yield strength of 800 MPa (116 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 86% of steel grades. Elongation at break is 17% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
8622 QT-28-32HRC is rated for continuous service to 425°C (797 °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 QT-28-32HRC 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 QT-28-32HRC 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 QT-28-32HRC's machinability is fair (48/100, worse than 57% of steel grades); weldability fair (50/100); formability good (58/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 8622 QT-28-32HRC
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.
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.
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 | — |
8622 QT-28-32HRC — frequently asked
What is 8622 QT-28-32HRC used for?
8622 QT-28-32HRC 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 QT-28-32HRC?
8622 QT-28-32HRC has a typical yield strength of 800 MPa (116 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 86% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 8622 QT-28-32HRC easy to machine?
Reasonably — machinability is rated fair (48/100, worse than 57% 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 QT-28-32HRC 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 QT-28-32HRC?
No anodizing — protect with black oxide, manganese phosphate, zinc plating or oil; carburized cases grind and superfinish well for gear flanks.
Can 8622 QT-28-32HRC 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 QT-28-32HRC?
8622 QT-28-32HRC is rated for continuous use to about 425°C (797 °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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.