Ti Grade 1 and Ti Grade 2 are the two basic grades of commercially pure titanium. Neither contains alloying elements; the difference between them is only in the permitted impurity levels — and in titanium that means strength directly.
Oxygen sets the strength
In pure titanium, oxygen is not an impurity but effectively a strengthener. In Grade 1 oxygen is ≤0.18%, in Grade 2 ≤0.25%. The iron limit in both is in the ≤0.20–0.30% range.
That small difference is reflected directly in the mechanical values: the yield strength of Grade 1 is ≥170 N/mm² against ≥275 N/mm² for Grade 2. Tensile strength rises from 240 to 345 N/mm². In exchange, Grade 1 stays more ductile: elongation ≥24% (≥20% in Grade 2) and hardness ≤120 HB (≤150 HB in Grade 2).
In terms of corrosion resistance there is no practical difference between the two grades; both behave excellently in seawater, chlorides and many acid environments.
Comparison in numbers
| PROPERTY | Ti Grade 1 | Ti Grade 2 |
|---|---|---|
| Oxygen (O) | ≤ 0.18% | ≤ 0.25% |
| Iron (Fe) | ≤ 0.20% | ≤ 0.30% |
| Nitrogen (N) | ≤ 0.03% | ≤ 0.03% |
| Carbon (C) | ≤ 0.08% | ≤ 0.08% |
| Hydrogen (H) | ≤ 0.015% | ≤ 0.015% |
| Tensile strength Rm | ≥ 240 N/mm² | ≥ 345 N/mm² |
| Yield strength Rp0.2 | ≥ 170 N/mm² | ≥ 275 N/mm² |
| Elongation | ≥ 24% | ≥ 20% |
| Hardness | ≤ 120 HB | ≤ 150 HB |
| Density | 4.51 g/cm³ | 4.51 g/cm³ |
| Modulus of elasticity | 105 kN/mm² | 105 kN/mm² |
| Thermal conductivity | 21 W/m·K | 20 W/m·K |
| UNS | R50250 | R50400 |
| AMS | 4940 | 4902 · 4941 · 4942 · 4951 |
Values are taken from our product datasheets; section thickness and the applied heat treatment regime change the result.
Which one, and when?
Ti Grade 1 is preferred — parts requiring deep drawing and complex forming, thin sheet and foil applications, explosive cladding, anode structures, heat exchanger plates. Anywhere formability matters more than strength.
Ti Grade 2 is preferred — chemical and marine industry piping, pressure vessels, pump bodies, architectural cladding, general purpose titanium parts. It is the “standard” grade of pure titanium; it is the most widely used CP titanium in the world and the easiest to source.
The other members of the family
For higher-strength pure titanium there is Ti Grade 4; for alloyed titanium, see our Ti Grade 2 – Grade 5 comparison.
Technical datasheets
Ti Grade 1 — chemical composition, mechanical values, standard equivalents
Ti Grade 2 — chemical composition, mechanical values, standard equivalents
Both grades are supplied to order in round bar, flat bar, plate, sheet, pipe and forged forms. Contact us for a quotation.