Titanium Grade 4 · heat-treated state
Titanium Grade 4-SR
Properties of the SR condition, compared with the other Grade 4 tempers.
Pick for straightness/dimensional stability after cold work or welding while keeping most of the cold-worked yield strength.
What is Grade 4-SR?
Grade 4-SR is Grade 4 heat treated to SR — pick for straightness/dimensional stability after cold work or welding while keeping most of the cold-worked yield strength. Grade 4-SR has a yield strength of 590 MPa (85.6 ksi) and a tensile strength of 660 MPa (95.7 ksi) — stronger than 50% of titanium grades. Elongation at break is 18% and the elastic modulus is 105 GPa (15.2 Msi). Grade 4-SR has a density of 4.51 g/cm³ (0.163 lb/in³), heavier than 57% of titanium grades. It melts at 1,660°C (3,020 °F). O is the default condition FabDigit quotes; SR is available on request or by drawing note.
Advantages
- Conducts heat well — 17.2 W/m·K (9.94 BTU/hr·ft·°F), better than 88% of titanium grades
Grade 4-SR properties
Typical room-temperature values for Grade 4-SR — 9 properties are specific to this condition; the rest are grade-level values shared by every Grade 4 temper. Each bar shows where the value sits among the titanium grades in FabDigit's library — further right is higher.
Physical3
Grade 4-SR has a density of 4.51 g/cm³ (0.163 lb/in³), heavier than 57% of titanium grades. It melts at 1,660°C (3,020 °F).
Mechanical16
Grade 4-SR has a yield strength of 590 MPa (85.6 ksi) and a tensile strength of 660 MPa (95.7 ksi) — stronger than 50% of titanium grades. Elongation at break is 18% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
Grade 4-SR is rated for continuous service to 300°C (572 °F). It conducts heat at 17.2 W/m·K (9.94 BTU/hr·ft·°F), better than 88% of titanium grades. Thermal expansion is 9 µm/m·K (5 µin/in·°F).
Electrical3
Grade 4-SR conducts electricity at 2.9 % IACS, better than 58% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (92/100), better than 53% of titanium grades.
Sustainability4
Producing a kilogram of Grade 4-SR takes about 700 MJ of energy and emits 45 kg of CO₂ — more than 74% of titanium grades. Typical recycled content is 25%.
Manufacturability8
Grade 4-SR's machinability is poor (30/100, better than 64% of titanium grades); weldability very good (80/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other Grade 4 tempers and conditions
Grade 4 is also supplied in 4 other conditions. The full side-by-side table is on the Grade 4 overview.
- ODefaultDefault stocked condition for sheet, plate, bar and tube — best balance of strength, ductility and weldability.550 MPa yield · 253 HB
- CWUse where maximum strength from unalloyed titanium is needed — dental implants, bone screws, high-pressure small-bore tube.700 MPa yield · 31 HRC
- SRPick for straightness/dimensional stability after cold work or welding while keeping most of the cold-worked yield strength.590 MPa yield · 265 HB
Working with Grade 4-SR
Is Grade 4 easy to machine?
Machine with rigid setups, sharp uncoated-carbide or coated inserts, low surface speed (25–45 m/min), heavy feed and flood coolant; never dwell — the low thermal conductivity and chip galling cause work hardening and fire risk from fine chips.
Can Grade 4 be welded?
Readily GTAW/GMAW/EB/laser welded with matching ERTi-4 filler under full argon/helium shielding plus trailing shield and backing gas; keep the weld and HAZ below straw colour, and avoid hydrogen/oxygen/nitrogen pickup which embrittles the joint.
Can Grade 4 be formed, bent or molded?
Cold form with generous bend radii (≈3–4 t) and allow for high springback; warm forming at 200–400 °C markedly improves formability, and hot working/forging is done at 815–955 °C.
What surface finishes work on Grade 4?
Pickle in HNO₃/HF to remove alpha case and scale after hot work, then bead blast, passivate, colour anodize (Type II) or hard anodize/nitride for wear; avoid iron-contaminated abrasives which spoil corrosion resistance.
Grade 4 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 |
|---|---|---|
| Nnitrogen, max | ≤ 0.05 | 0.02 |
| Ccarbon, max | ≤ 0.08 | 0.02 |
| Hhydrogen, max (0.0125 for some product forms) | ≤ 0.02 | 0.01 |
| Feiron, max | ≤ 0.5 | 0.3 |
| Ooxygen, max — main strengthener | ≤ 0.4 | 0.34 |
| Residual eachother elements, each | ≤ 0.1 | — |
| Residual totalother elements, total | ≤ 0.4 | — |
| Tibalance, ≈99.0 % min | balance | — |
Grade 4-SR — frequently asked
What is Grade 4-SR used for?
Grade 4-SR is typically used for aircraft tubing and airframe fittings, surgical instruments and hand tools, orthopaedic and dental components, high-strength fasteners, cryogenic and pressure-vessel parts and chemical plant hardware. In short: high-strength CP titanium.
What is the yield strength of Grade 4-SR?
Grade 4-SR has a typical yield strength of 590 MPa (85.6 ksi) and a tensile strength of 660 MPa (95.7 ksi) — stronger than 50% of titanium grades. Strength varies by condition: see the 5 listed tempers.
Is Grade 4-SR easy to machine?
Not especially — machinability is rated poor (30/100, better than 64% of titanium grades). Machine with rigid setups, sharp uncoated-carbide or coated inserts, low surface speed (25–45 m/min), heavy feed and flood coolant; never dwell — the low thermal conductivity and chip galling cause work hardening and fire risk from fine chips.
Can Grade 4-SR be welded?
Yes — weldability is rated very good (80/100). Readily GTAW/GMAW/EB/laser welded with matching ERTi-4 filler under full argon/helium shielding plus trailing shield and backing gas; keep the weld and HAZ below straw colour, and avoid hydrogen/oxygen/nitrogen pickup which embrittles the joint.
What surface finishes work on Grade 4-SR?
Pickle in HNO₃/HF to remove alpha case and scale after hot work, then bead blast, passivate, colour anodize (Type II) or hard anodize/nitride for wear; avoid iron-contaminated abrasives which spoil corrosion resistance.
Can Grade 4-SR be formed, bent or molded?
Cold form with generous bend radii (≈3–4 t) and allow for high springback; warm forming at 200–400 °C markedly improves formability, and hot working/forging is done at 815–955 °C.
What is the maximum service temperature of Grade 4-SR?
Grade 4-SR is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Grade 4-O and Grade 4-CW?
O is the default condition — default stocked condition for sheet, plate, bar and tube — best balance of strength, ductility and weldability. CW: use where maximum strength from unalloyed titanium is needed — dental implants, bone screws, high-pressure small-bore tube. Yield strength is 550 MPa in O versus 700 MPa in CW.
Can FabDigit make parts in Grade 4-SR?
Yes — Grade 4-SR 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 B265 — Titanium and Titanium Alloy Strip, Sheet, and Plate — ASTM International (2020)
- ASTM B348 — Titanium and Titanium Alloy Bars and Billets — ASTM International (2021)
- ASTM F67 — Unalloyed Titanium for Surgical Implant Applications — ASTM International (2017)
- AWS A5.16 — Titanium and Titanium-Alloy Welding Electrodes and Rods — AWS (2013)
- GB/T 3621 — (TA4) — SAC (2022)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol.13B / Vol.16 — Corrosion and Machining — ASM International (2005)
- CP Titanium Grade 4 mill product data — TIMET / Baoji Titanium (2023)
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.