Titanium Grade 23
ASTM Grade 23 · UNS R56401, R56407 · EN Ti6Al4V ELI, 3.7165 · GB TC4-1, TC4ELI · ISO 5832-3
Grade 23 (Ti-6Al-4V ELI, UNS R56401 / R56407, ASTM F136, B265, B348, 3.7165, TC4ELI) is the extra-low-interstitial version of the alpha-beta workhorse Ti-6Al-4V, with reduced oxygen and iron for higher fracture toughness and fatigue life.
Values for the O condition
Grade 23 tempers and conditions
Grade 23 is supplied in 8 conditions, soft to hard. O 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 |
|---|---|---|---|---|---|---|
annealed above the β transus (≈1015–1050 °C) then slow cooled + stabilise | Select for damage-tolerant thick sections where high fracture toughness and slow crack growth outrank yield strength. | 820 | 900 | 11 | 33 HRC | 1 % IACS |
ODefault Annealed | Default stocked condition for bar, plate, sheet and implant blanks; best balance of strength, ductility and toughness. | 850 | 930 | 15 | 33 HRC | — |
Hot isostatic pressed | Specify for castings and AM parts where internal porosity must be closed to reach wrought-level fatigue life. | 865 | 950 | 15 | 33 HRC | — |
hot worked, not annealed | Rough stock condition for forging billet and heavy bar that will be machined and heat treated later. | 870 | 950 | 13 | 34 HRC | 1 % IACS |
480–650 °C stress relief after cold work, welding or printing | Choose when residual stress from machining, forming, welding or AM must be removed with minimal loss of strength. | 890 | 970 | 13 | 34 HRC | — |
Cold worked | Standard condition for ELI implant wire and small-diameter bar needing higher strength and straightness. | 960 | 1,050 | 10 | 36 HRC | 1 % IACS |
Solution treated and aged | Pick for maximum strength in thinner sections (fasteners, high-load fittings) accepting reduced toughness and ductility. | 1,010 | 1,100 | 10 | 36 HRC | — |
laser/electron-beam powder bed fusion, as-built (no post-heat treatment) | Use only where high as-built strength is wanted and anisotropy, residual stress and low ductility are acceptable. | 1,050 | 1,150 | 9 | 38 HRC | — |
What is Grade 23?
Grade 23 (Ti-6Al-4V ELI, UNS R56401 / R56407, ASTM F136, B265, B348, 3.7165, TC4ELI) is the extra-low-interstitial version of the alpha-beta workhorse Ti-6Al-4V, with reduced oxygen and iron for higher fracture toughness and fatigue life. It is supplied as bar, plate, sheet, wire and powder for laser powder-bed fusion, and is the standard biomedical implant titanium, giving 850 MPa yield, 930 MPa tensile, 15% elongation, 320 HB (33 HRC) and a 113 GPa modulus. Service is limited to about 350 °C and machinability is very poor (score 20); bare surfaces gall and wear badly. Standard Grade 5 is the lower-cost alternative where ELI toughness is not required. Grade 23 has a density of 4.43 g/cm³ (0.16 lb/in³), lighter than 89% of titanium grades. It melts at 1,604°C (2,919 °F). Grade 23 has a yield strength of 850 MPa (123 ksi) and a tensile strength of 930 MPa (135 ksi) — stronger than 66% of titanium grades. Elongation at break is 15% and the elastic modulus is 113 GPa (16.4 Msi).
What is Grade 23 used for?
- Orthopaedic implants such as hip and knee stems
- Spinal hardware
- Bone screws, plates and trauma fixation
- Dental implants and abutments
- Additively manufactured patient-specific implants
- Fracture-critical aerospace fittings
- Cryogenic and subsea pressure components
- Surgical instrument bodies
Advantages
- Polishes to a fine finish — 80/100, better than 98% of titanium grades
- Tough — resists crack growth — 85 MPa·√m (77.4 ksi·√in), better than 91% of titanium grades
Limitations
- Poor heat conductor — 6.7 W/m·K (3.87 BTU/hr·ft·°F), worse than 92% of titanium grades
- Low electrical conductivity — 1 % IACS, worse than 89% of titanium grades
Grade 23 properties
Typical room-temperature values for Grade 23-O; bars are the position among titanium grades.
Physical3
Grade 23 has a density of 4.43 g/cm³ (0.16 lb/in³), lighter than 89% of titanium grades. It melts at 1,604°C (2,919 °F).
Mechanical16
Grade 23 has a yield strength of 850 MPa (123 ksi) and a tensile strength of 930 MPa (135 ksi) — stronger than 66% of titanium grades. Elongation at break is 15% and the elastic modulus is 113 GPa (16.4 Msi).
Thermal6
Grade 23 is rated for continuous service to 350°C (662 °F). It conducts heat at 6.7 W/m·K (3.87 BTU/hr·ft·°F), worse than 92% of titanium grades. Thermal expansion is 8.6 µm/m·K (4.78 µin/in·°F).
Electrical3
Grade 23 conducts electricity at 1 % IACS, worse than 89% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (92/100), better than 53% of titanium grades.
Sustainability4
Producing a kilogram of Grade 23 takes about 700 MJ of energy and emits 45 kg of CO₂ — more than 74% of titanium grades. Typical recycled content is 15%.
Manufacturability8
Grade 23's machinability is poor (20/100, worse than 68% of titanium grades); weldability very good (80/100); formability fair (35/100).
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 titanium family
Yield strength against density for every titanium grade FabDigit runs. Grade 23 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Grade 23
Is Grade 23 easy to machine?
Low speed, high feed, rigid setup, sharp uncoated-carbide or PVD tools and flood coolant — heat concentrates at the edge and the alloy work-hardens and galls; avoid dwell and light rubbing passes.
Can Grade 23 be welded?
Excellent by GTAW, plasma, laser or EBW with full argon/vacuum shielding front and back plus trailing shield; keep interstitials low, weld clean bright metal, and stress relieve — no filler contamination or air exposure above ~400 °C.
Can Grade 23 be formed, bent or molded?
Cold formability is limited (large bend radii, high springback); hot form or size at 600–800 °C, or superplastically form near 900 °C in an inert/lubricated die.
Manufacturability
The process limits FabDigit's quote engine applies to Grade 23. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Fair20 / 100 |
|---|---|
| ISO material group | S.3 |
| Cutting speed (rough / finish) | 60 / 75 m/min |
| Minimum wall | 1 mm |
| Minimum internal radius | 1.5 mm |
| Drill depth limit | 4× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Fair35 / 100 |
|---|---|
| Weldability | Good80 / 100 |
3D printing
| Technologies | DMLS |
|---|---|
| Layer height | 20 – 60 µmdefault 30 µm |
| Minimum wall / feature | 0.5 / 0.3 mm |
| Build envelope | 250 × 250 × 325 mm |
| Supports | Yes |
| Anisotropy | Mild |
| Mandatory post-processing | heat treatment |
Grade 23 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 |
|---|---|---|
| Alα stabiliser | 5.5 – 6.5 | 6 |
| Vβ stabiliser | 3.5 – 4.5 | 4 |
| Fe | ≤ 0.25 | 0.15 |
| OELI limit — key difference vs Grade 5 (0.20 max) | ≤ 0.13 | 0.1 |
| N | ≤ 0.05 | 0.02 |
| C | ≤ 0.08 | 0.02 |
| H0.0125 % for some product forms | ≤ 0.01 | 0.01 |
| YASTM F136 residual yttrium limit | ≤ 0.01 | |
| Other, each | ≤ 0.1 | |
| Other, total | ≤ 0.4 | |
| Ti | balance |
What surface finishes work on Grade 23?
Polishes to mirror implant finish; passivate per ASTM F86, anodize or colour-anodize for identification, and consider shot peen, nitriding or PVD hard coats since bare Ti-6Al-4V has poor wear and galling resistance.
Surface treatments FabDigit runs on titanium 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).
Passivation
Conversion Coating
Organic Coating
CVD Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Titanium Grade 23 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- R56401R56407
- ASTM
- F136F1472B348 Grade 23
- AMS
- 49074930
- EN / DIN / Werkstoff-Nr.
- Ti6Al4V ELI3.7165
- ISO
- 5832-3
- GB (China)
- TC4-1TC4ELI
- Trade names
- Extra Low Interstitial
- Also called
- TC4-ELI
How much does Grade 23 cost?
Grade 23 is a high-cost titanium ($$$$), pricier than about 99% 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.
Grade 23 — frequently asked
What is Grade 23 used for?
Grade 23 is typically used for orthopaedic implants such as hip and knee stems, spinal hardware, bone screws, plates and trauma fixation, dental implants and abutments, additively manufactured patient-specific implants and fracture-critical aerospace fittings. In short: ELI medical-grade titanium.
What is the yield strength of Grade 23?
Grade 23 has a typical yield strength of 850 MPa (123 ksi) and a tensile strength of 930 MPa (135 ksi) — stronger than 66% of titanium grades. Strength varies by condition: see the 8 listed tempers.
Is Grade 23 easy to machine?
Not especially — machinability is rated poor (20/100, worse than 68% of titanium grades). Low speed, high feed, rigid setup, sharp uncoated-carbide or PVD tools and flood coolant — heat concentrates at the edge and the alloy work-hardens and galls; avoid dwell and light rubbing passes.
Can Grade 23 be welded?
Yes — weldability is rated very good (80/100). Excellent by GTAW, plasma, laser or EBW with full argon/vacuum shielding front and back plus trailing shield; keep interstitials low, weld clean bright metal, and stress relieve — no filler contamination or air exposure above ~400 °C.
What surface finishes work on Grade 23?
Polishes to mirror implant finish; passivate per ASTM F86, anodize or colour-anodize for identification, and consider shot peen, nitriding or PVD hard coats since bare Ti-6Al-4V has poor wear and galling resistance.
Can Grade 23 be formed, bent or molded?
Cold formability is limited (large bend radii, high springback); hot form or size at 600–800 °C, or superplastically form near 900 °C in an inert/lubricated die.
What is the maximum service temperature of Grade 23?
Grade 23 is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Grade 23-O and Grade 23-STA?
O is the default condition — default stocked condition for bar, plate, sheet and implant blanks; best balance of strength, ductility and toughness. STA: pick for maximum strength in thinner sections (fasteners, high-load fittings) accepting reduced toughness and ductility. Yield strength is 850 MPa in O versus 1,010 MPa in STA.
How much does Grade 23 cost?
Grade 23 is a high-cost titanium ($$$$), pricier than about 99% 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 Grade 23?
Yes — Grade 23 is available for CNC machining, sheet metal and 3D printing with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM F136 — Wrought Ti-6Al-4V ELI Alloy for Surgical Implant Applications (UNS R56401) — ASTM International (2022)
- ASTM B348 / B265 — Titanium and Titanium Alloy Bar, Billet, Strip and Plate (Grade 23) — ASTM International (2021)
- ISO 5832-3 — Implants for surgery, metallic materials, wrought Ti-6Al-4V alloy — ISO (2021)
- AMS 4907 / AMS 4930 — Ti-6Al-4V ELI sheet, plate and bar — SAE International (2020)
- ASTM F3001 — Additive Manufacturing Ti-6Al-4V ELI with Powder Bed Fusion — ASTM International (2022)
- Materials Properties Handbook: Titanium Alloys — ASM International (1994)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- MMPDS typical/design allowables for Ti-6Al-4V — Battelle/FAA (2023)
- Ti-6Al-4V ELI (Grade 23) mill and AM powder datasheets — Baoti / Western Superconducting / AP&C (2024)
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.