Steel 8620 · temper
Steel 8620 Annealed
Properties of the Annealed condition, compared with the other 8620 tempers.
Pick for maximum machinability, deep cold forming or before re-heat-treatment.
What is 8620 Annealed?
8620 Annealed is 8620 in the Annealed temper — pick for maximum machinability, deep cold forming or before re-heat-treatment. 8620 Annealed has a yield strength of 385 MPa (55.8 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 65% of steel grades. Elongation at break is 31% and the elastic modulus is 205 GPa (29.7 Msi). 8620 Annealed 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). HR is the default condition FabDigit quotes; Annealed is available on request or by drawing note.
Advantages
- Easy to machine — 68/100, better than 95% of steel grades
- Ductile — tolerates forming and impact — 31%, better than 94% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
- Forms and bends easily — 65/100, better than 81% of steel grades
8620 Annealed properties
Typical room-temperature values for 8620 Annealed — 11 properties are specific to this condition; the rest are grade-level values shared by every 8620 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
8620 Annealed 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
8620 Annealed has a yield strength of 385 MPa (55.8 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 65% of steel grades. Elongation at break is 31% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
8620 Annealed is rated for continuous service to 400°C (752 °F). It conducts heat at 46.6 W/m·K (26.9 BTU/hr·ft·°F), better than 74% of steel grades. Thermal expansion is 11.6 µm/m·K (6.44 µin/in·°F).
Electrical3
8620 Annealed conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of 8620 Annealed takes about 30 MJ of energy and emits 2.1 kg of CO₂ — more than 55% of steel grades. Typical recycled content is 30%.
Manufacturability7
8620 Annealed's machinability is good (68/100, better than 95% of steel grades); weldability good (60/100); formability good (65/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 8620 tempers and conditions
8620 is also supplied in 9 other conditions. The full side-by-side table is on the 8620 overview.
- HRDefaultStandard stocked condition for bar and plate that will be machined and then carburized or Q&T.385 MPa yield · 183 HB
- Q&TChoose when the whole section must carry load (shafts, arbors) rather than only a carburized surface.850 MPa yield · 31 HRC
- CarburizedThe main reason to specify 8620: hard wear/pitting-resistant case on a tough core for gears, splines and pins.850 MPa yield · 60 HRC
- CDChoose for close-tolerance, good-finish bar with higher yield strength where no further heat treatment is planned.550 MPa yield · 205 HB
- HIPPick when residual porosity from printing/sintering must be closed for fatigue-critical gear or shaft parts.430 MPa yield · 200 HB
- AnnealedPick for maximum machinability, deep cold forming or before re-heat-treatment.385 MPa yield · 149 HB
- As PrintedUse for additively made gear-steel prototypes and small-lot parts that will subsequently be carburized or Q&T.380 MPa yield · 190 HB
- NormalizedUse to homogenize forgings/bar and get uniform grain size and good toughness before carburizing.360 MPa yield · 183 HB
Working with 8620 Annealed
Is 8620 easy to machine?
Machines well at ~65 % of AISI 1212 in HR/annealed condition; finish-machine before carburizing and allow grinding stock for case distortion.
Can 8620 be welded?
Weldable with low-hydrogen consumables at 0.20 % C; preheat 150–250 °C, use matching low-alloy filler and post-weld stress relieve; never weld a carburized surface.
Can 8620 be formed, bent or molded?
Cold heading and moderate bending are fine in annealed/HR condition; hot forge 1150–1230 °C and normalize afterwards to restore grain size.
What surface finishes work on 8620?
No anodizing (ferrous); protect with black oxide, phosphate, zinc or zinc-nickel plating, or oil — post-carburizing grinding gives the final gear-tooth finish.
8620 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 |
|---|---|---|
| Cheat analysis, SAE/ASTM A29 | 0.18 – 0.23 | 0.2 |
| 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; 8620H/resulfurized variants differ | ≤ 0.04 | — |
| Fe | balance | — |
8620 Annealed — frequently asked
What is 8620 Annealed used for?
8620 Annealed is typically used for gears, ring gears and camshafts. In short: best carburizing steel.
What is the yield strength of 8620 Annealed?
8620 Annealed has a typical yield strength of 385 MPa (55.8 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 65% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 8620 Annealed easy to machine?
Reasonably — machinability is rated good (68/100, better than 95% of steel grades). Machines well at ~65 % of AISI 1212 in HR/annealed condition; finish-machine before carburizing and allow grinding stock for case distortion.
Can 8620 Annealed be welded?
Yes — weldability is rated good (60/100). Weldable with low-hydrogen consumables at 0.20 % C; preheat 150–250 °C, use matching low-alloy filler and post-weld stress relieve; never weld a carburized surface.
What surface finishes work on 8620 Annealed?
No anodizing (ferrous); protect with black oxide, phosphate, zinc or zinc-nickel plating, or oil — post-carburizing grinding gives the final gear-tooth finish.
Can 8620 Annealed be formed, bent or molded?
Cold heading and moderate bending are fine in annealed/HR condition; hot forge 1150–1230 °C and normalize afterwards to restore grain size.
What is the maximum service temperature of 8620 Annealed?
8620 Annealed 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 8620-HR and 8620-CR?
HR is the default condition — standard stocked condition for bar and plate that will be machined and then carburized or Q&T. CR: sheet and strip form for stamped, then carburized parts; better surface and thickness tolerance than hot rolled. Yield strength is 385 MPa in HR versus 560 MPa in CR.
Can FabDigit make parts in 8620 Annealed?
Yes — 8620 Annealed is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM International (2020)
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- GB/T 3077 (20CrNiMo) — SAC (2015)
- EN 10084 — Case hardening steels (1.6523 / 21NiCrMo2-2) — CEN (2008)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (carburizing) — ASM International (1991)
- MatWeb / MMPDS typical property listings for AISI 8620 — MatWeb / Battelle (2023)
- Binder-jet and L-PBF low-alloy 8620 powder data sheets — ExOne / Desktop Metal (2022)
- 20CrNiMo — Mysteel / 1688 (2026)
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.