Is Grade 1 Titanium Good? A Complete Engineering Guide
May 19, 2026
What Is Grade 1 Titanium?
Grade 1 titanium (UNS R50250, DIN 3.7025, GB/T TA1) is the softest and most ductile of the four commercially pure (CP) titanium grades defined by ASTM. Its composition is tightly controlled, with Fe ≤ 0.20%, O ≤ 0.18%, C ≤ 0.08%, N ≤ 0.03%, and H ≤ 0.015% maximum, balance titanium. The low interstitial content maximizes ductility, impact toughness, and formability while retaining the excellent corrosion resistance common to all CP grades.
Classification Clarified: CP Grades versus Alloys
A frequent misunderstanding is to treat Grade 5 as a commercially pure grade. In the ASTM system, only Grades 1 to 4 are commercially pure titanium. Grade 5 (Ti-6Al-4V) is an alpha-beta alloy containing about 6% aluminum and 4% vanadium. The CP grades differ mainly in oxygen and iron levels, which control strength: Grade 1 is the softest and Grade 4 the strongest of the CP family.
| Grade | Type | Oxygen max | Strength Level |
|---|---|---|---|
| Grade 1 | CP | 0.18% | Lowest |
| Grade 2 | CP | 0.25% | Moderate |
| Grade 3 | CP | 0.35% | Higher |
| Grade 4 | CP | 0.40% | Highest CP |
| Grade 5 | α+β alloy | 0.20% | Highest overall |
Mechanical Properties of Grade 1
| Property | Value |
|---|---|
| Tensile strength (min) | 240 MPa |
| Yield strength 0.2% offset | 170–310 MPa |
| Elongation (min) | 24% |
| Density | 4.51 g/cm³ |
| Thermal conductivity | 16 W/m·K |
Per ASTM B265, the minimum tensile strength of annealed Grade 1 strip, sheet, and plate is 240 MPa. The low yield strength end (about 170 MPa) enables excellent deep drawing and complex forming. These values are consistent across the page so that buyers compare like-for-like.
Applications of Grade 1 Titanium
Because of its formability and corrosion resistance, Grade 1 is used for gaskets, heat exchanger tubing, storage tanks, aircraft skins, marine hardware, bicycle frames, and medical-grade items per ASTM F67 for surgical implants. It is also a common choice for architectural cladding and chemical process equipment where deep drawing or severe bending is required.
Grade 1 vs Grade 2 vs Grade 5: Harmonized Data
| Property | Grade 1 | Grade 2 | Grade 5 |
|---|---|---|---|
| UTS (MPa, min) | 240 | 345 | 895 |
| Yield (MPa) | 170–310 | 275 min | 825 min |
| Elongation (%, min) | 24 | 20 | 10 |
| Density (g/cm³) | 4.51 | 4.51 | 4.43 |
Choose Grade 1 when formability and ductility dominate, Grade 2 for a balance of strength and corrosion resistance, and Grade 5 when high strength and fatigue resistance are required.
Machining and Welding
Grade 1 machines well with sharp carbide tools, low speeds, and adequate lubrication to prevent galling. Welding is straightforward with GTAW or PAW using ERTi-1 filler and argon shielding on both sides. Post-weld stress relief may be applied for complex assemblies.
Frequently Asked Questions
Is Grade 1 titanium stronger than Grade 2?
No. Grade 2 has a higher minimum tensile strength (345 MPa) than Grade 1 (240 MPa) because of higher allowable oxygen content. Grade 1 trades some strength for maximum ductility.
What is Grade 1 titanium used for?
Typical uses include gaskets, heat exchanger tubing, storage tanks, aircraft skins, marine hardware, deep-drawn parts, and medical items such as surgical tools and implants per ASTM F67.
Is Grade 1 titanium corrosion resistant?
Yes. Like all CP grades, it forms a stable self-healing oxide film and resists seawater, chlorides, and many acids, with high resistance to pitting and crevice corrosion.
Can Grade 1 titanium be welded?
Yes. GTAW and PAW with ERTi-1 filler and proper argon shielding give sound welds; post-weld treatment may be needed for demanding service.
What is the difference between Grade 1 and Grade 5 titanium?
Grade 1 is a soft CP grade with minimum UTS of 240 MPa and elongation of 24%, while Grade 5 is an alpha-beta alloy with minimum UTS of 895 MPa and elongation of 10%. Grade 5 is about three times stronger but far less formable.
Is Grade 1 titanium biocompatible?
Yes. ASTM F67 covers Grade 1 unalloyed titanium for surgical implant applications, and it is used for implants and surgical instruments where ductility is valued.
