Titanium is the go-to material for CNC-machined parts that demand an exceptional strength-to-weight ratio, corrosion resistance in aggressive environments, or certified biocompatibility. Where aluminum alloys reach their limits in temperature or load - and where stainless steel is simply too heavy - titanium delivers. This guide covers the grades Clarwe commonly machines, their mechanical properties, design-for-manufacturability (DFM) considerations, achievable tolerances, and available surface finishes to help you specify parts with confidence.
Why Use Titanium for CNC Machining?
Titanium offers a combination of structural and chemical properties that few metals can match:
High specific strength - supports lighter parts than steel at equivalent load capacity.
Corrosion resistance - performs well in seawater, chlorides, and aggressive chemicals.
Biocompatibility - suitable for medical and body-contact applications.
Thermal stability - maintains useful properties beyond most aluminum alloy limits.
Non-magnetic - useful for sensitive instruments and MRI-adjacent environments.
Titanium Grades for CNC Machining
Overview of Common Grades
Most CNC-machined titanium parts are produced from a small set of well-established grades. The table below shows typical reference properties. Exact values depend on grade specification, supplier, heat treatment, and test method - treat these as indicative engineering ranges only.
| Material | Density (g/cm³) | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation at Break (%) | Hardness (Brinell) (HBW) | Fatigue Strength (MPa) |
|---|---|---|---|---|---|---|
| Grade 1 | ∼4.5 | 170-240 | 240-350 | 24-30 | 120-140 | ∼170 |
| Grade 2 | ∼4.51 | 275-400 | 345-500 | 20-25 | 140-200 | 240-300 |
| Grade 4 | ∼4.50 | 483-655 | 550-740 | 15-20 | 200-250 | ∼300 |
| Grade 5 | 4.43-4.47 | 880-1100 | 900-1170 | 5-15 | 330-380 | 160-600 |
Titanium Grade 1
Titanium Grade 1 is the softest and most ductile of the commercially pure titanium grades. Its very low oxygen content gives it the highest formability and weldability of any titanium grade, with excellent corrosion resistance across a wide range of media including reducing and oxidising acids.
Typical applications: Thin-wall chemical processing equipment, heat exchangers, desalination hardware, low-stress medical components, and applications where formability and weldability matter more than maximum tensile strength.
Machinability: Grade 1's lower hardness makes it relatively more forgiving than higher-strength grades. Its ductility means chips can be long and stringy - sharp tools, consistent chip load, and adequate coolant are essential to avoid built-up edge and surface smearing. Carbide tooling is recommended over HSS.
Titanium Grade 2
Titanium Grade 2 is the industry workhorse among commercially pure grades. It provides a reliable balance of strength, corrosion resistance, and ductility that suits a broad range of industrial, marine, and medical applications.
Typical applications: Pressure vessels, heat exchangers, marine fittings, chemical processing components, medical implants, and general parts requiring titanium's chemical resistance and biocompatibility without the full cost and machining complexity of Grade 5.
Machinability: Grade 2 is notably more machinable than Grade 5. When significant stock removal is required, Grade 2 is often preferred to manage tooling wear and overall part cost - a key DFM consideration worth raising at the design stage.
Titanium Grade 4
Titanium Grade 4 is the strongest commercially pure titanium grade. It offers higher yield and tensile strength than Grades 1–3 while retaining acceptable corrosion resistance and weldability - bridging the gap between commercially pure grades and the Ti-6Al-4V alloy.
Typical applications: Surgical implants and instruments, airframe structural components, cryogenic vessel fittings, and parts that require more strength than Grade 2 but without the alpha-beta alloy complexity of Grade 5.
Machinability: Grade 4 is harder than Grades 1 and 2 and requires more careful attention to cutting parameters and tool life. It is less commonly machined than Grade 2 or Grade 5 but is well-established for precision surgical and aerospace components.
Titanium Grade 5 (Ti-6Al-4V)
Ti-6Al-4V is the most widely used titanium alloy for CNC-machined parts globally, accounting for approximately 50% of all titanium consumed in industrial applications. Its combination of very high strength, low density, excellent fatigue resistance, and good corrosion resistance makes it the default specification for demanding structural applications.
Typical applications: Aerospace fasteners and structural brackets, turbine and engine components, motorsport suspension and drivetrain parts, high-performance bicycle frames, and load-bearing orthopaedic implants including hip stems, spinal cages, and bone screws.
Machinability: Grade 5 is the most challenging titanium grade to machine. Its high strength, low thermal conductivity (~6.7 W/m·K), and tendency to work-harden under rubbing tool contact require careful process control. Lower cutting speeds, higher feed-per-tooth, sharp coated carbide tooling, and high-pressure coolant delivery are all required. When designed correctly and machined with appropriate parameters, Grade 5 can be held to tight tolerances and fine surface finishes reliably.
Design Guidelines for CNC-Machining of Titanium Parts
Titanium's material characteristics introduce specific machining challenges that are best addressed at the design stage. Understanding these early avoids costly revisions, extended lead times, and scrap.
Thermal Behaviour and Tool Wear
Titanium's low thermal conductivity (~6.7 W/m·K, vs. ~170 W/m·K for aluminum 6061 and ~50 W/m·K for steel) means cutting heat concentrates at the tool-chip interface rather than dissipating into the chip or workpiece. This accelerates tool wear dramatically and can cause microstructural surface damage if not managed.
Recommended strategies:
- Use sharp carbide end mills and inserts - uncoated or TiAlN/TiCN-coated grades rated specifically for titanium.
- Keep cutting speeds conservative: 40–70 m/min for commercially pure grades (1, 2, 4); 30–55 m/min for Grade 5 in most milling operations.
- Maintain sufficient feed-per-tooth so the tool cuts rather than rubs. Rubbing triggers work hardening and rapidly destroys tool edges.
- Apply high-pressure through-spindle coolant (minimum 70 bar where available) to flush chips from the cut zone and cool the tool directly.
- Inspect and replace tooling at scheduled intervals - do not run titanium with worn edges.
Chatter, Deflection, and Rigidity
Titanium's high strength combined with a relatively low elastic modulus (~114 GPa vs. ~200 GPa for steel) means thin walls, slender ribs, and long unsupported features deflect more under cutting forces than equivalent steel features. This makes chatter and dimensional drift common problems in under-supported setups.
Recommended design practices:
- Minimum wall thickness: 0.8 mm for non-structural walls; 1.5 mm recommended where structural rigidity is needed.
- Internal corner radii: Use the largest radius your design permits. A general minimum is 1/3 of the cavity depth. Avoid sharp internal corners, which require slow plunge cuts and increase tool breakage risk.
- Tool overhang: Keep tool length-to-diameter (L:D) ratio below 4:1 where possible. Use stub-length tooling for deep features.
- Toolpaths: Trochoidal and adaptive milling strategies maintain consistent radial chip load, reduce peak cutting forces, and significantly decrease heat buildup in deep pockets and narrow slots. Climb milling is preferred over conventional milling for titanium.
- Fixturing: Rigid, well-supported fixturing is critical. Parts must be fixtured close to the cutting zone, especially for thin-section aerospace and medical parts.
Heat Treatment Sequencing for Grade 5
For Ti-6Al-4V (Grade 5) parts with tight final tolerances:
- Machine in the annealed condition - annealed Ti-6Al-4V is softer and more machinable than the solution-treated and aged (STA) condition.
- Heat treat after machining - specify solution treatment and ageing (STA) to the required final mechanical specification post-machining.
- Account for minor distortion - heat treatment after machining can cause small dimensional shifts. For ultra-critical features, specify a final light machining or grinding pass after heat treatment.
Achievable Tolerances for Titanium in CNC Machining
Standard and Tight Tolerances
Tighter tolerances may require additional operations such as grinding or EDM finishing. Consult Clarwe's engineers at the RFQ stage with your drawing and GD&T callouts.
| Feature Type | Standard Tolerance | Tight Tolerance (on request) |
|---|---|---|
| Linear dimensions | ±0.125 mm | ±0.025 mm |
| Hole diameters | ±0.050 mm | ±0.013 mm |
| Flatness / straightness | ±0.050 mm | ±0.013 mm |
| Wall thickness (minimum) | 0.8 mm | 0.5 mm (Grade 2 only) |
| Surface roughness (as-machined) | Ra 0.8–3.2 µm | Ra 0.4 µm (on request) |
Surface Finish Options for Titanium Parts
Surface finishing is often the final step in tailoring titanium parts for dimensional requirements, corrosion performance, cleanability, and appearance.
Available Surface Finishes
| Finish | Typical Ra | Key Benefits | Common Applications |
|---|---|---|---|
| As-Machined | Ra 0.8–3.2 µm | Functional surfaces with visible tool marks; maintains tightest tolerances | General industrial, structural parts |
| Bead Blasted | Ra 1.6–3.2 µm | Uniform matte texture; removes surface stress risers; good cosmetic appearance | Medical housings, aerospace brackets, consumer parts |
| Polished | Ra 0.2–0.8 µm | Smooth, clean surface; suits sealing faces and implant-contact surfaces | Orthopaedic implants, fluid-contact components |
| Anodized (Type II) | Sub-micron oxide | Colour-coded oxide layer through light interference (no dyes); minimal dimensional change | Medical instruments, consumer goods, colour-coded parts |
| Passivation | - | Restores native TiO₂ oxide layer post-machining; enhances corrosion resistance | Medical implants, chemical processing parts |
For specific cosmetic or performance requirements, Clarwe's engineers can recommend the right combination of machining strategy and surface finish for your titanium part.
Industry Applications of Titanium
Titanium's property profile makes it the material of record across several demanding sectors.
Aerospace and Defence
Titanium's high specific strength and thermal stability make it standard in airframes, engine mounts, structural fasteners, hydraulic manifolds, and actuator components. Grade 5 (Ti-6Al-4V) is the dominant aerospace specification, with Grade 2 used for ducting, heat shields, and corrosion-critical fittings.
Medical and Dental
Biocompatibility, corrosion resistance in biological fluids, and non-ferromagnetism - critical for MRI compatibility - make titanium the default for orthopaedic implants (hip stems, knee tibial trays, spinal cages, bone screws), dental implants and abutments, surgical instruments, and diagnostic housings.
Motorsport and High-Performance Automotive
Titanium connecting rods, suspension uprights, exhaust systems, wheel fasteners, and roll-cage fittings are specified where weight reduction directly improves lap times or vehicle dynamics. Grade 5 is standard; Grade 2 is used for exhaust and heat-exposed fittings.
Oil, Gas, and Marine
Titanium's resistance to chlorides and seawater makes it ideal for subsea fittings, heat exchanger tube bundles, pump bodies, valve components, and offshore structural fittings where stainless steel would experience pitting or crevice corrosion over time.
Industrial and Chemical Processing
Reactor liners, agitator shafts, filter housings, pressure vessel heads, and pipe fittings in aggressive chemical environments - including hydrochloric acid, nitric acid, and chlorine-containing streams - are common titanium applications where its corrosion immunity eliminates the need for expensive coatings or frequent replacement.
Consumer, Sporting, and Wearable Goods
High-end bicycle frames, watch cases, camera bodies, dive equipment, and premium consumer electronics use titanium for its combination of low weight, durability, scratch resistance, and premium aesthetic - increasingly specified for colour-anodized components.
Titanium vs Other Metals: When to Choose What
| Property | Titanium Grade 5 | Aluminum 6061-T6 | Stainless Steel 316 |
|---|---|---|---|
| Density (g/cm³) | 4.43–4.47 | ~2.70 | 7.9–8.0 |
| Yield Strength (MPa) | 880–1,100 | 240–280 | 170-310 |
| Tensile Strength (MPa) | 900–1,170 | 290–320 | 480–620 |
| Elongation at Break (%) | 5–15 | 8–14 | 40–50 |
| Hardness (HBW) | 330–380 | 90–100 | 140–190 |
| Fatigue Strength (MPa) | 160–600 | 90–110 | 240–310 |
| Machinability | Challenging | Excellent | Moderate (~40%) |
| Biocompatibility | Yes | No | Limited |
| Relative Material Cost | High | Low | Moderate |
Titanium vs Aluminum
- Titanium delivers significantly higher strength, superior creep and fatigue performance at elevated temperatures, and far better corrosion resistance in aggressive media, including seawater and chloride-rich environments.
- Titanium is approximately 43% lighter than steel but ~56% heavier than aluminum - the strength-to-weight advantage over aluminum is in load intensity, not raw mass reduction.
- Aluminum is the better choice for moderate-load, low-temperature, non-corrosive applications where cost is a primary design constraint and weight savings can be achieved through geometry rather than material selection.
- Choose titanium over aluminum when: loads are high, operating temperatures exceed ~150°C, the environment is chemically aggressive, or biocompatibility is a regulatory requirement.
Titanium vs Stainless Steel
- Titanium offers a higher strength-to-weight ratio and far better resistance in chloride-rich and seawater environments where austenitic stainless steels (including 316) are susceptible to pitting and crevice corrosion.
- At ~4.5 g/cm³, titanium is roughly 43% lighter than stainless steel at ~8.0 g/cm³ - a significant advantage in aerospace, medical, and motorsport applications where mass is closely managed.
- Stainless steel can sustain higher continuous service temperatures (~870°C vs. ~315°C for titanium) and is the more economical choice where weight reduction and chloride resistance are not critical requirements.
- Choose titanium over stainless steel when: weight reduction is a primary goal, the part is exposed to chlorides or seawater, or biocompatibility and MRI compatibility are mandatory.
Titanium vs Tool Steel / Alloy Steel
- High-strength alloy and tool steels can match or exceed titanium's absolute tensile strength, but at more than double the density (~7.8 g/cm³). In load-critical, weight-constrained structures titanium is the clear choice.
- Steels are significantly easier and cheaper to machine, heat-treat, and source, making them the standard for tooling, dies, and parts where weight is not a constraint.
- Choose titanium over steel when: the strength-to-weight ratio is a critical design metric, or when corrosion resistance eliminates the need for secondary coating or plating processes.
Frequently Asked Questions
Which titanium grade should I choose for CNC machining?
Grade 2 is often the best choice for corrosion-resistant industrial parts and applications that benefit from better machinability, while Grade 5 (Ti-6Al-4V) is preferred for high-strength, weight-critical aerospace, motorsport, and medical components. Grade 1 is used where maximum ductility and formability matter, and Grade 4 is selected when higher strength is needed within the commercially pure titanium family.
What tolerances can Clarwe hold on CNC-machined titanium parts?
Standard tolerances are ±0.125 mm (±0.005"). Tight tolerances down to ±0.025 mm (±0.001") are achievable on critical features on request, with hole diameters and flatness holdable to ±0.013 mm. Features requiring tighter callouts may need secondary operations such as grinding or EDM finishing. Submit your drawing with GD&T callouts at the RFQ stage for feasibility confirmation.
How much does CNC machining titanium cost compared to aluminum?
Titanium parts typically cost significantly more than equivalent aluminum parts. The premium comes from higher raw material cost per kg, longer cycle times due to conservative cutting speeds, and faster tooling consumption. Selecting Grade 2 over Grade 5 where performance allows, minimising material removal, using standard stock sizes, and avoiding unnecessarily tight tolerances on non-critical features are the most effective ways to manage cost.
How does titanium anodizing work and what colours are available?
Titanium anodizing (Type II) creates a colour through light interference in the TiO₂ oxide layer — no dyes are involved. Colour is controlled by voltage: lower voltages produce gold and bronze; higher voltages shift through blue, purple, green, and grey. The oxide layer is nanometres thick with negligible dimensional impact, making it suitable for tight-tolerance parts. It is commonly specified for colour-coding surgical instruments and aesthetic consumer components.
What is the typical lead time for CNC-machined titanium parts?
Lead time depends on part complexity, grade, order volume, and finish requirements. Standard machined titanium parts are typically deliverable within 10–15 business days. Prototypes or simple geometries may be available sooner. Parts requiring additional finishing such as anodizing, passivation, or post-machining heat treatment will add to lead time. Contact our team with your drawing for a confirmed schedule at the time of quoting.
Not sure which titanium grade, tolerance, or finish is right for your application? Send us your requirements and our engineers will recommend the right specification for your part.