Grade 2 Titanium
Commercially Pure Titanium - Unalloyed

Grade 2 Titanium

Supreme Corrosion Resistance • Excellent Formability • Superior Weldability

Grade 2 is the most commonly used commercially pure (CP) titanium, offering the best balance of strength, corrosion resistance, and fabricability among unalloyed titanium grades. With exceptional resistance to a wide range of corrosive environments and excellent formability, it's the workhorse material for chemical processing, marine, and industrial applications where corrosion resistance is paramount.

Chemical Processing Marine Grade Easy to Weld Formable

Quick Specifications

UNS Number: R50400
ASTM: B265, B338
Grade: Grade 2
Density: 4.51 g/cm³
Melting Point: 1668°C
Magnetic: No
345
Tensile Strength (MPa)
275
Yield Strength (MPa)
20%
Elongation
99.2%
Titanium Purity
B
Machinability

Properties & Characteristics

Material Overview

Grade 2 is unalloyed titanium (99.2% minimum purity) with controlled levels of interstitial elements (oxygen, iron, carbon, nitrogen). It represents the optimal balance point among commercially pure titanium grades, offering moderate strength combined with excellent ductility, superior corrosion resistance, and outstanding formability. The absence of alloying elements provides maximum corrosion resistance and weldability.

Key Benefits

Outstanding Corrosion Resistance: Superior to all stainless steels in most environments
Excellent Formability: Can be cold formed, deep drawn, and hydroformed
Superior Weldability: Easiest titanium grade to weld; excellent joint properties
High Ductility: 20% elongation provides excellent damage tolerance
Biocompatible: Excellent for medical devices and implantable components
Lightweight: 43% lighter than steel with good strength

Commercially Pure Advantage

As an unalloyed grade, Grade 2 titanium offers maximum chemical compatibility and corrosion resistance. Without alloying elements that can create galvanic cells or preferential corrosion sites, it provides uniform, predictable performance in aggressive chemical environments. The material's alpha phase microstructure (single-phase HCP crystal structure) contributes to excellent formability and weldability that surpass alloyed grades like Ti-6Al-4V.

Limitations

Moderate Strength: Lower strength than Ti-6Al-4V (345 MPa vs 950 MPa)
Temperature Limit: Not suitable for high-temperature structural applications above 300°C
Galling Tendency: Can seize when in sliding contact with itself

Chemical Composition

Element Maximum % Notes
Titanium (Ti) Balance (99.2% min) Base metal - commercially pure
Oxygen (O) 0.25 max Primary strengthening interstitial (controlled)
Iron (Fe) 0.30 max Impurity limit (Beta stabilizer)
Carbon (C) 0.08 max Impurity limit (strengthener)
Nitrogen (N) 0.03 max Impurity limit (strengthener)
Hydrogen (H) 0.015 max Must be minimized (causes embrittlement)
Residual Elements 0.40 max (total) Each element ≤0.10%

Purity Note: Grade 2 is "commercially pure" rather than "pure" because it contains controlled levels of interstitial elements (O, C, N) that provide strength. These elements are intentionally controlled within tight ranges to balance strength and ductility. True pure titanium (99.99%) would be too soft for structural use.

Grade Comparison

Grade 1
0.18% O max - softest, most formable
Grade 2 ⭐
0.25% O max - best balance
Grade 3
0.35% O max - higher strength

Mechanical Properties (Annealed)

Property Metric Imperial
Tensile Strength (Ultimate) 345 MPa (min) 50,000 psi (min)
Yield Strength (0.2% offset) 275 MPa (min) 40,000 psi (min)
Elongation at Break 20% minimum (in 50mm)
Reduction of Area 30% minimum
Modulus of Elasticity 103 GPa 15.0 × 10⁶ psi
Rockwell Hardness 80 HRB (typical)
Brinell Hardness 200 HB (typical)
Shear Strength 220 MPa 32,000 psi
Shear Modulus 45 GPa 6.5 × 10⁶ psi
Poisson's Ratio 0.34

Strength vs. Formability Trade-off

Grade 2's moderate strength (345 MPa) combined with high ductility (20% elongation) makes it ideal for applications requiring complex forming operations. While Ti-6Al-4V offers 2.75× the strength, Grade 2's superior formability enables cold forming, deep drawing, and complex shapes impossible with alloyed titanium.

Physical Properties

Density
4.51 g/cm³
0.163 lb/in³ (57% of steel)
Melting Point
1668°C
3034°F
Maximum Service Temperature
300°C
570°F (continuous)
Thermal Conductivity
16.0 W/m-K
@ 20°C
Coefficient of Thermal Expansion
8.9 µm/m-K
20-100°C
Electrical Resistivity
550 nΩ-m
@ 20°C
Specific Heat Capacity
528 J/kg-K
@ 25°C
Crystal Structure
Alpha (α)
HCP - Single Phase

Industry Applications

Chemical Processing (Primary Application)

Heat exchangers, reaction vessels, process piping, valves, pumps, tanks, pressure vessels, chlorine production equipment, fertilizer plants, electroplating equipment, pickling equipment, and components exposed to aggressive acids, alkalies, and salt solutions.

Marine & Offshore

Seawater cooling systems, heat exchanger tubing, condenser tubing, offshore platform components, desalination equipment, ballast tanks, ship propeller shafts, marine fasteners, underwater equipment housings, and saltwater service applications.

Power Generation

Condenser tubes in power plants, heat exchanger systems, geothermal power equipment, steam turbine blades, flue gas desulfurization systems, and corrosive service applications in power generation facilities.

Architectural & Construction

Architectural cladding, roofing materials, exterior panels, monuments, sculptures, handrails, decorative applications, building facades, and applications where corrosion resistance and aesthetics are important.

Medical Devices

Surgical instruments, medical equipment housings, prosthetic devices, dental instruments, sterilization equipment, and non-implantable medical components requiring biocompatibility and sterilization resistance.

Industrial Equipment

Electrowinning cathodes, plating equipment, pulp and paper processing, hydrometallurgical equipment, vacuum systems, and general industrial components requiring corrosion resistance and formability.

CNC Machining Guidelines

B
Machinability Rating
Good - Better than Ti-6Al-4V due to lower strength

Easier Than Alloyed Titanium

Grade 2's lower strength (345 MPa vs 950 MPa for Ti-6Al-4V) and single-phase alpha microstructure make it significantly easier to machine than alloyed titanium grades. However, it still requires titanium-specific machining practices due to low thermal conductivity and chemical reactivity.

  • • Lower cutting forces than Ti-6Al-4V
  • • Better surface finish achievable
  • • Still requires sharp tools and flood coolant
  • • Work hardening still occurs but less severe

Best Practices

  • • Use sharp uncoated carbide tools
  • • Maintain moderate cutting speeds
  • • Heavy feed rates recommended
  • • Flood coolant essential
  • • Rigid machine setup
  • • Avoid tool dwelling or rubbing
  • • Positive rake angles (15-20°)

Tooling Recommendations

  • • Uncoated C-2 carbide preferred
  • • TiN or TiAlN coatings acceptable
  • • HSS usable for low-speed operations
  • • Sharp cutting edges critical
  • • Large nose radius for finishing
  • • Strong tool holders
Operation Recommended Parameters
Turning (Roughing) Speed: 80-120 SFM (24-37 m/min), Feed: 0.010-0.020 ipr
Turning (Finishing) Speed: 120-180 SFM (37-55 m/min), Feed: 0.005-0.010 ipr
Milling Speed: 120-200 SFM (37-61 m/min), Heavy feeds, climb milling
Drilling Speed: 30-60 SFM (9-18 m/min), Peck drilling for deep holes
Threading Moderate speeds, thread milling or form taps work well
Coolant Flood coolant REQUIRED - water-soluble or chlorinated oils

Machining Advantage: Grade 2's lower hardness and strength make it approximately 30-40% easier to machine than Ti-6Al-4V. Higher cutting speeds are possible, tool life is extended, and better surface finishes can be achieved with less effort.

Fabrication & Forming

Exceptional Formability

Grade 2 titanium is the most formable titanium alloy, with excellent ductility that enables complex forming operations impossible with higher-strength grades. The single-phase alpha microstructure provides uniform deformation characteristics and superior deep drawing capability.

Forming Capabilities

  • Cold Forming: Excellent for room temperature operations
  • Deep Drawing: Drawing ratios up to 2.3:1
  • Bending: Tight radii possible (2-3× thickness)
  • Roll Forming: Complex profiles achievable
  • Hydroforming: Excellent for complex shapes
  • Spinning: Superior to alloyed grades

Forming Advantages

  • • Lower spring-back than steel
  • • No age hardening issues
  • • Can be annealed if work hardened
  • • Excellent surface finish retention
  • • No special lubricants required
  • • Room temperature forming common

Annealing for Formability

For severe forming operations, Grade 2 can be annealed to maximize ductility:

  • • Temperature: 650-760°C (1200-1400°F)
  • • Time: 15-30 minutes per 25mm of thickness
  • • Atmosphere: Inert gas or vacuum (prevent contamination)
  • • Cooling: Air cool to room temperature

Welding Excellence

Grade 2 is the easiest titanium grade to weld, with excellent weld joint properties and minimal risk of weld defects. The absence of alloying elements eliminates concerns about segregation or second-phase precipitation in the weld zone.

Superior Weldability

  • Best of all titanium grades - Easiest to achieve high-quality welds
  • Full strength welds - Weld zone matches base metal properties
  • Minimal distortion - Low thermal expansion reduces warping
  • No heat treatment required - Use in as-welded condition
  • Excellent ductility - Weld zone remains ductile

Suitable Processes

  • • GTAW (TIG) - Preferred method
  • • Plasma Arc Welding
  • • GMAW (MIG) - With careful control
  • • Electron Beam Welding
  • • Laser Welding
  • • Resistance Welding (spot, seam)

Filler Metal

  • • ERTi-2 (matching composition)
  • • ERTi-1 (for softer welds)
  • • AWS A5.16 specification
  • • Clean, oxide-free wire essential
  • • Store in dry environment

Still Requires Shielding

While Grade 2 is easier to weld than alloyed titanium, argon shielding remains MANDATORY to prevent atmospheric contamination. Use front, backing, and trailing shields for critical applications. Weld color (silver = good, gray/white = contaminated) indicates quality.

Outstanding Corrosion Resistance

Grade 2 titanium provides exceptional corrosion resistance that surpasses even the most corrosion-resistant stainless steels. The stable TiO₂ passive film, combined with the absence of alloying elements that can create galvanic cells, delivers maximum corrosion protection.

Superior to Alloyed Titanium

In many corrosive environments, Grade 2's corrosion resistance actually exceeds that of Ti-6Al-4V. The absence of aluminum and vanadium eliminates preferential corrosion sites and provides more uniform passive film formation. This makes Grade 2 the preferred choice for chemical processing and marine applications.

Excellent Resistance To:

  • • Seawater (all temperatures)
  • • Chloride solutions (all concentrations)
  • • Nitric acid (all concentrations)
  • • Chromic acid
  • • Organic acids
  • • Alkaline solutions
  • • Wet chlorine gas
  • • Oxidizing chloride solutions
  • • Hypochlorite solutions
  • • Most natural environments

Limited Resistance To:

  • • Hydrofluoric acid (all concentrations)
  • • Hot concentrated hydrochloric acid
  • • Sulfuric acid (>10% concentration, hot)
  • • Phosphoric acid (>10%, hot)
  • • Oxalic acid (hot)
  • • Red fuming nitric acid
  • • Reducing acids without oxidizers

Chemical Processing Advantage

Grade 2's resistance to pitting, crevice corrosion, and stress corrosion cracking in chloride environments is unmatched by stainless steels. In chemical processing applications, Grade 2 equipment can last decades without corrosion-related failures, while stainless steel alternatives may fail in months.

Overview

Material Type
Commercially Pure Titanium
Purity Level
99.2% Minimum
Crystal Structure
Alpha (HCP) - Single Phase
Weldability
Excellent (Best of all Ti grades)
Formability
Outstanding
Typical Forms
Sheet, Plate, Tube, Pipe, Wire

Standards & Designations

UNS
R50400
Grade
Grade 2
ASTM
B265, B338, B348
ASME
SB-265, SB-338
AMS
4902
AWS
A5.16 (ERTi-2)

vs. Ti-6Al-4V

Corrosion Resistance
Grade 2 Superior
Better in most environments
Formability
Grade 2 Superior
20% vs 10% elongation
Weldability
Grade 2 Superior
Easier, better results
Strength
Ti-6Al-4V Superior
950 vs 345 MPa

Need Grade 2 Titanium Components?

Get a quote for AS9100D certified Grade 2 titanium machining with full material traceability and chemical processing certification.

Related Titanium & Corrosion-Resistant Materials