Steel 8630
AISI/SAE 8630 · UNS G86300
8630 (UNS G86300) is a through-hardening Ni-Cr-Mo low-alloy steel of moderate carbon content from the SAE-AISI 86xx family.
Values for the HR condition
8630 tempers and conditions
8630 is supplied in 8 conditions, soft to hard. HR 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 |
|---|---|---|---|---|---|---|
Temper | Fully/spheroidize annealed (~845 °C, furnace cool) for maximum softness before heavy machining or cold forming. | 372 | 565 | 29 | 156 HB | — |
HRDefault Hot rolled | Mill hot-rolled bar/plate as most commonly stocked; buy when parts will be heat treated after machining. | 415 | 690 | 22 | 197 HB | — |
Heat Treat State | Normalized ~870 °C air cool: uniform fine grain and good toughness, typical pre-condition for forgings and weldments. | 430 | 650 | 23.5 | 187 HB | — |
sour service (NACE MR0175/ISO 15156) | High-temperature temper limiting hardness to 22 HRC max for H2S-containing (sour) subsea and wellhead components. | 585 | 790 | 22 | 20 HRC | — |
Cold rolled | Cold-rolled strip/sheet with tight thickness and smooth surface; higher strength but low ductility, usually stress-relieved before forming. | 620 | 760 | 12 | 20 HRC | 8 % IACS |
Cold drawn | Cold-drawn bar for good size tolerance, straightness and improved machined finish without further heat treatment. | 655 | 760 | 15 | 223 HB | 44 W/m·K |
Quenched and tempered | Oil quenched from ~860 °C and tempered ~540–595 °C to about 28–32 HRC — the standard structural/oilfield condition balancing strength and toughness. | 860 | 1,000 | 18 | 30 HRC | — |
low-temperature temper, high strength | Tempered ~315–425 °C for high strength shafts, pins and fasteners where toughness demands are moderate. | 1,280 | 1,400 | 12 | 43 HRC | — |
What is 8630?
8630 (UNS G86300) is a through-hardening Ni-Cr-Mo low-alloy steel of moderate carbon content from the SAE-AISI 86xx family. In the annealed/hot-rolled condition it runs about 197 HB (93 HRB) with 415 MPa yield, 690 MPa tensile and 22 % elongation, and is quench-and-tempered to 22 HRC or 40–45 HRC for shafts, gears and pressure-containing forgings. Hardenability and toughness in heavy sections are the reasons engineers pick it, mostly as bar and forging stock. It has no inherent corrosion resistance and its carbon equivalent of about 0.75 makes preheat and PWHT mandatory for welding; 4140 or 4340 are the usual step-ups in strength. 8630 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). 8630 has a yield strength of 415 MPa (60.2 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 56% of steel grades. Elongation at break is 22% and the elastic modulus is 205 GPa (29.7 Msi).
What is 8630 used for?
- Shafts
- Gears
- Fittings
8630 properties
Typical room-temperature values for 8630-HR; bars are the position among steel grades.
Physical3
8630 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).
Mechanical13
8630 has a yield strength of 415 MPa (60.2 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 56% of steel grades. Elongation at break is 22% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
8630 is rated for continuous service to 400°C (752 °F). It conducts heat at 43 W/m·K (24.8 BTU/hr·ft·°F), better than 51% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
8630 conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 8630 takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 35%.
Manufacturability7
8630's machinability is good (60/100, better than 83% of steel grades); weldability fair (40/100); formability fair (40/100).
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. 8630 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 8630
Is 8630 easy to machine?
Machines best annealed or ~200 HB (about 65 % of AISI 1212); use rigid setups, carbide tooling and reduced speeds above 30 HRC.
Can 8630 be welded?
Weldable with low-hydrogen consumables but CE ≈0.75 demands 200–300 °C preheat, controlled interpass and PWHT/re-temper to avoid HAZ cracking.
Can 8630 be formed, bent or molded?
Hot forge 1100–1200 °C and normalize afterwards; cold forming only in the annealed condition with generous bend radii.
Manufacturability
The process limits FabDigit applies to 8630. Every 8630 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better60 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Fair40 / 100 |
|---|---|
| Weldability | Better40 / 100 |
8630 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 |
|---|---|---|
| C | 0.28 – 0.33 | 0.3 |
| 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 |
What surface finishes work on 8630?
No inherent corrosion resistance — protect by phosphating, zinc/Ni plating, thermal spray or paint; nitriding and induction hardening give good wear surfaces (avoid electroplating >32 HRC without bake-out).
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).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel 8630 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- G86300
How much does 8630 cost?
8630 is a standard-cost steel ($$), cheaper than about 71% 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.
8630 — frequently asked
What is 8630 used for?
8630 is typically used for shafts, gears and fittings. In short: workhorse Cr-Mo bar.
What is the yield strength of 8630?
8630 has a typical yield strength of 415 MPa (60.2 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 56% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 8630 easy to machine?
Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Machines best annealed or ~200 HB (about 65 % of AISI 1212); use rigid setups, carbide tooling and reduced speeds above 30 HRC.
Can 8630 be welded?
With care — weldability is rated fair (40/100). Weldable with low-hydrogen consumables but CE ≈0.75 demands 200–300 °C preheat, controlled interpass and PWHT/re-temper to avoid HAZ cracking.
What surface finishes work on 8630?
No inherent corrosion resistance — protect by phosphating, zinc/Ni plating, thermal spray or paint; nitriding and induction hardening give good wear surfaces (avoid electroplating >32 HRC without bake-out).
Can 8630 be formed, bent or molded?
Hot forge 1100–1200 °C and normalize afterwards; cold forming only in the annealed condition with generous bend radii.
What is the maximum service temperature of 8630?
8630 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 8630-HR and 8630-CD?
HR is the default condition — mill hot-rolled bar/plate as most commonly stocked; buy when parts will be heat treated after machining. CD: cold-drawn bar for good size tolerance, straightness and improved machined finish without further heat treatment. Yield strength is 415 MPa in HR versus 655 MPa in CD.
How much does 8630 cost?
8630 is a standard-cost steel ($$), cheaper than about 71% 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.
Can FabDigit make parts in 8630?
Yes — 8630 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- ASTM A322 — Alloy Steel Bars, Standard Grades — ASTM (2019)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- NACE MR0175 / ISO 15156 — Materials for H2S-containing environments — NACE/ISO (2015)
- Machinery's Handbook, 31st ed. — Industrial Press (2020)
- Mysteel / SMM (2025)
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.