Titanium Grade 1 is a commercially pure titanium grade known for its excellent corrosion resistance, high ductility and outstanding formability. Of the four principal commercially pure titanium grades, Grade 1 has the lowest strength and highest ductility.
This combination makes Grade 1 particularly suitable for components requiring extensive forming, deep drawing or fabrication while retaining the corrosion resistance associated with commercially pure titanium.
Grade 1 is designated UNS R50250. Its mechanical strength is controlled primarily by the permitted levels of oxygen, iron and other residual or interstitial elements rather than by conventional alloy additions.
Grade 1 Chemical Composition
| Element | Weight % |
|---|---|
| Titanium (Ti) | Balance |
| Oxygen (O) | ≤ 0.18 |
| Iron (Fe) | ≤ 0.20 |
| Carbon (C) | ≤ 0.08 |
| Nitrogen (N) | ≤ 0.03 |
| Hydrogen (H) | ≤ 0.015 |
These values are specification limits rather than a nominal recipe.
Grade 1 Mechanical Properties
Representative minimum properties for common annealed material include:
| Property | Value |
|---|---|
| Ultimate tensile strength | ≥ 240 MPa |
| 0.2% yield strength | ≥ 138 MPa |
| Elongation | ≥ 24% |
| Density | approximately 4.51 g/cm³ |
Exact mechanical requirements depend on product form, thickness and specification.
Key Characteristics
Grade 1 combines excellent corrosion resistance with lower strength and greater ductility than Grades 2, 3 and 4. It can tolerate substantial forming operations and is readily welded when appropriate shielding procedures are used.
Its passive titanium-oxide surface gives good resistance in many oxidising environments, including seawater and numerous chloride-bearing process streams.
Typical Applications
- Chemical-processing equipment
- Heat exchangers
- Plate and frame heat-exchanger components
- Piping and tubing
- Marine equipment
- Architectural components
- Formed and deep-drawn titanium components
- Medical components where the applicable specification permits commercially pure titanium
Common Specifications
- ASTM B265 — sheet, strip and plate
- ASTM B348 — bar and billet
- ASTM F67 — unalloyed titanium for surgical implant applications
- AMS 4940 — commercially pure Grade 1 sheet, strip and plate
Technical Note
Chemical and mechanical properties shown are representative of commonly referenced specifications. Requirements can vary by product form, thickness, heat treatment and governing standard. Material should be ordered to the required specification, and the supplied material test report (MTR) should be used to verify compliance.
