Steel 8625H
Grade
AISI/SAE 8625 · UNS G86250
8625H = hardenability-guaranteed (H-band) grade
Order this when Jominy end-quench hardenability limits must be certified for consistent case/core response.
Values for the 8625H condition
Other 8625 tempers and conditions
8625 is listed in 9 conditions; see the grade overview at 8625.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest condition; pick for heavy machining, cold forming or deep boring before carburizing. | 340 | 540 | 28 | 156 HB | — |
NDefault Normalized | Standard stocked/starting condition: uniform fine grain for machining and subsequent carburizing. | 400 | 620 | 24 | 187 HB | 7.8 % IACS |
Hot rolled | Cheapest mill condition for parts that will be fully re-heat-treated after rough machining. | 400 | 640 | 22 | 192 HB | 7.8 % IACS |
8625HThis page Hardenability-guaranteed (H-band) grade | Order this when Jominy end-quench hardenability limits must be certified for consistent case/core response. | 400 | 620 | 24 | 187 HB | 7.8 % IACS |
Cold drawn | Cold-finished bar with tight tolerance and better surface; use where parts are machined lightly and case-hardened locally. | 580 | 690 | 15 | 207 HB | 7.8 % IACS |
Q&T 28–32 HRC | Through-hardened medium-strength condition for shafts and non-carburized structural parts. | 800 | 965 | 17 | 30 HRC | — |
core properties (30–40 HRC core) | Core mechanical data used for gear-tooth bending and shaft sizing of carburized 8625 parts. | 940 | 1,150 | 13 | 36 HRC | 7.8 % IACS |
Q&T 33–38 HRC | Higher-strength through-hardened condition for loaded shafts, still machinable with carbide tooling. | 1,000 | 1,150 | 14 | 35 HRC | 7.8 % IACS |
Carburized, direct quenched and low-temperature tempered (case 58–62 HRC) | Primary service condition: hard wear-resistant case over a tough 30–40 HRC core for gears and splines. | 1,000 | 1,250 | 10 | 60 HRC | — |
What is 8625H?
8625H is 8625 in the 8625H grade — order this when Jominy end-quench hardenability limits must be certified for consistent case/core response. 8625H has a yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of steel grades. Elongation at break is 24% and the elastic modulus is 205 GPa (29.7 Msi). 8625H 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). N is the default condition FabDigit quotes; 8625H is available on request or by drawing note.
8625H properties
Typical room-temperature values for 8625H; 21 are specific to this condition. Other listed values are 8625 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
8625H 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
8625H has a yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of steel grades. Elongation at break is 24% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
8625H 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 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
8625H 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 8625H takes about 27 MJ of energy and emits 2.1 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 30%.
Manufacturability7
8625H's machinability is good (60/100, better than 83% of steel grades); weldability good (55/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 8625H
Is 8625 easy to machine?
Machine in annealed or normalized condition (≈60% of AISI 1212) with carbide tooling; finish grind after carburizing to correct heat-treat distortion.
Can 8625 be welded?
Weldable with low-hydrogen filler but requires 150–250 °C preheat and post-weld tempering; avoid welding carburized surfaces.
Can 8625 be formed, bent or molded?
Hot forge 1150–1200 °C then normalize; cold forming limited to annealed bar with generous bend radii.
What surface finishes work on 8625?
Not anodizable — protect with black oxide, manganese phosphate, zinc plating or oil; case-hardened surfaces should be ground, not chemically stripped aggressively.
8625 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 / ASTM A29 | 0.23 – 0.28 | 0.25 |
| 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 | — |
| S | ≤ 0.04 | — |
| Fe | balance | — |
8625H — frequently asked
What is 8625H used for?
8625H is typically used for gears, shafts and cam parts. In short: highest core hardness 86xx; moderately loaded gear steel; H-band grade available.
What is the yield strength of 8625H?
8625H has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is 8625H easy to machine?
Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Machine in annealed or normalized condition (≈60% of AISI 1212) with carbide tooling; finish grind after carburizing to correct heat-treat distortion.
Can 8625H be welded?
Yes — weldability is rated good (55/100). Weldable with low-hydrogen filler but requires 150–250 °C preheat and post-weld tempering; avoid welding carburized surfaces.
What surface finishes work on 8625H?
Not anodizable — protect with black oxide, manganese phosphate, zinc plating or oil; case-hardened surfaces should be ground, not chemically stripped aggressively.
Can 8625H be formed, bent or molded?
Hot forge 1150–1200 °C then normalize; cold forming limited to annealed bar with generous bend radii.
What is the maximum service temperature of 8625H?
8625H 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 8625-N and 8625-CD?
N is the default condition — standard stocked/starting condition: uniform fine grain for machining and subsequent carburizing. CD: cold-finished bar with tight tolerance and better surface; use where parts are machined lightly and case-hardened locally. Yield strength is 400 MPa in N versus 580 MPa in CD.
Sources
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- SAE J1268 — Hardenability Bands for Carbon and Alloy H Steels — SAE International (2019)
- 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.