TI · titanium
Titanium Grade 4 (commercially pure, higher strength)
The strongest of the commercially pure grades - roughly the strength of a mild steel with the corrosion resistance of titanium, and about as hard to cut as a stainless.
Quoting this material
- Typical lead time
- 10–15 working days
- Condition
- Annealed
- Achievable finish
- Ra 1.6 µm typical · Ra 0.4 µm best
Machined in-house to your drawing: see the precision CNC machining service and the machine and inspection capability it runs on.
Machinability
Our own 1–10 shop ranking, not a published index: 10 is free-cutting brass C360, 1 is Inconel 718. It ranks how a material behaves on the floor - cycle time, chip control and tool life together. Where a published index exists it is quoted in the note.
The strongest of the commercially pure grades - roughly the strength of a mild steel with the corrosion resistance of titanium, and about as hard to cut as a stainless.
Properties as supplied
| Parameter | Value | Unit |
|---|---|---|
| Tensile strength | 550 | MPa |
| Yield strength (0.2%) | 483 | MPa |
| Elongation | 15 | % |
| Hardness | 175 | HV |
| Thermal conductivity | 17.4 | W/m·K (approx.) |
| Modulus of elasticity | 104 | GPa |
Hardness, tensile and thermal figures are typical published values for the condition stated. Actual mill certificates govern; send the specification with the drawing and we confirm against the certificate before the material is cut.
Condition
Annealed
Heat treatment
Not hardenable by heat treatment. Cold work is what raises its strength, so any annealing is a stress relief, not a strengthening step.
Achievable surface finish
Ra 1.6 µm
Ra 0.4 µm
Takes a good finish; the same chlorine and contamination rules as the other grades apply.
Tooling and cutting parameters
Cutting speed
- 50–100 m/min (carbide)
Feed
- 0.10–0.22 mm/rev turning · 0.06–0.14 mm/tooth milling
Tooling
- Uncoated fine-grain carbide, sharp geometry, rigid setup
Coolant
- High-pressure flood, no chlorinated fluids
Starting points for carbide on a rigid setup, not a guarantee. The right numbers depend on the machine, the toolholder and the fixturing - ask and we will say what we would actually run.
Typical applications
- Pressure vessel and valve components
- Chemical pump bodies
- Marine and offshore fasteners
- Condenser and heat exchanger parts
- Medical grade hardware
DFM notes for this grade
- The extra strength over Grade 2 comes with less ductility: a tight bend radius that works in Grade 2 can crack in Grade 4
- It is the highest-strength commercially pure grade, which makes it the right answer where weldability and corrosion matter but the load does not need an alloy
- Higher hardness than Grade 2 means slightly better chip formation and slightly worse tool wear - expect to change inserts sooner
Questions buyers ask
- Grade 4 or Ti-6Al-4V for a pressure part?
- Grade 4 where the design is wall-thickness driven and the part is welded, because it is more weldable and more ductile. Ti-6Al-4V where the strength is the constraint - but its weldability in thick sections needs a controlled procedure.
- Why is titanium specified for chemical service rather than a stainless?
- Where the chemistry attacks stainless - chlorides at temperature, oxidising acids, wet chlorine. Titanium forms a stable oxide film that 316L cannot, and Grade 4 carries the pressure with the corrosion resistance.