What does "titanium grade" mean, and how is it different from a single material?

A titanium grade is a formal material specification that defines the chemical composition limits, mechanical property minimums, and acceptable product forms (bar, sheet, plate, etc.). Different grades have different amounts of alloying elements or different purity levels, which produce significantly different strength, machinability, and cost characteristics. When you specify "Grade 2 titanium per ASTM B348," you are communicating a complete material requirement — not just a metal type. Without the grade designation, "titanium" on a drawing is an incomplete specification. A supplier could legally ship any titanium material if no grade is called out.

Does using a stronger grade always mean better performance?

No — over-specifying is a common and costly mistake. Using Ti-6Al-4V (Grade 5) where Grade 2 would meet the structural requirement adds 50–70% to material cost and 15–25% to cycle time, without any functional benefit. Stronger materials also machine more aggressively — higher cutting forces, faster tool wear — which increases scrap risk. The correct approach is to run a structural analysis first: if Grade 2 passes with an adequate factor of safety (typically FOS ≥ 2.0 on UTS for static loads), it is the better specification. Only upgrade to Grade 5 when the analysis shows Grade 2 is insufficient.

What is the most commonly used titanium grade for CNC machining?

Ti-6Al-4V (Grade 5, AMS 4928) is the most commonly used titanium alloy for CNC machined parts, accounting for over 50% of all titanium machined components. It provides the best balance of strength (130 ksi / 896 MPa UTS), weight (4.43 g/cm³), and availability. CP Grade 2 (ASTM B348) is the second most common grade, used primarily for applications where corrosion resistance is the primary requirement and high strength is not — marine hardware, chemical processing, and non-load-bearing medical devices. Grade 23 ELI (ASTM F136) is used exclusively for implantable medical devices.

When should I use CP Grade 2 instead of Ti-6Al-4V?

Use CP Grade 2 titanium when: (1) Corrosion resistance is the primary requirement and the part is not load-bearing or highly stressed. (2) Higher formability or weldability is needed — Grade 2 bends and forms more easily than Ti-6Al-4V without cracking. (3) Cost reduction is important — Grade 2 material costs $10–18/lb ($22–40/kg) vs. $15–30/lb ($33–66/kg) for Ti-6Al-4V, and machines 15–25% faster. (4) You are producing parts for chemical processing, marine environments, or desalination equipment where CP purity ensures superior resistance to reducing acid environments. If the structural analysis shows Ti-6Al-4V provides FOS > 3:1 on yield, Grade 2 is likely acceptable and will reduce total part cost by 25–35%.

Is Grade 5 titanium strong enough for most engineering applications?

Yes — Ti-6Al-4V Grade 5 at 130 ksi (896 MPa) UTS covers the vast majority of structural applications requiring titanium. For context: 6061-T6 aluminum is 45 ksi (310 MPa), 304 stainless is 84 ksi (579 MPa), 4140 steel heat-treated is 125–150 ksi (862–1,034 MPa). Grade 5 titanium provides steel-level strength at 57% of steel's density. The cases where Grade 5 is insufficient: ultra-high-cycle fatigue applications requiring Grade 23 ELI (medical implants), or applications requiring 150+ ksi that specify Grade 5 STA condition (solution treat and age to 150–165 ksi). Beta titanium alloys (Grade 19, 21) can reach 180+ ksi but are rarely specified for CNC machined parts.

Can I switch titanium grades after a design is released?

Switching titanium grades on a released engineering drawing requires an Engineering Change Order (ECO) and potentially additional qualification data. For non-regulated applications (industrial, commercial), switching Grade 5 to Grade 2 or vice versa is a material substitution that requires re-analysis (stress analysis, corrosion analysis) and drawing revision. For regulated applications (medical devices, etc.), a grade change typically requires: updated material specification on drawing, re-validation per the applicable standard (ISO 13485 or equivalent quality system), and potentially customer or regulatory notification. Never substitute grades on a drawing without formal approval — material substitution is a common nonconformance finding in quality audits.

Selection Guide · 10 min read

Which Titanium Grade Should You Use?

Three grades cover 95%+ of CNC machined titanium applications: CP Grade 2 for corrosion resistance at lower strength, Ti-6Al-4V Grade 5 for the best strength-to-weight ratio, and Grade 23 ELI for load-bearing implantable medical devices. Use this guide to select the right grade — and avoid over-specifying.

By MakerStage EngineeringMarch 10, 2026

See Decision Matrix Start a Quote Review

Quick Answer

Need corrosion resistance, not high strength?

CP Grade 2 per ASTM B348

Need high strength-to-weight + corrosion resistance?

Ti-6Al-4V Grade 5 per AMS 4928

Implantable load-bearing medical device?

Ti-6Al-4V ELI Grade 23 per ASTM F136

Just need titanium for prototyping/testing?

Grade 5 — most available, best docs

Scroll to explore

Start Here — Quick Answer

What Grade Should You Use? Start With These Three Questions

Titanium grade selection boils down to three sequential questions. Answer them in order, and the right grade becomes clear:

1. Is the part an implantable medical device that will be subject to cyclic loading (fatigue)?

Yes: Use Grade 23 (Ti-6Al-4V ELI, ASTM F136). No substitutions without regulatory review.

No: Continue to question 2.

2. Does the structural analysis require UTS greater than 50 ksi (345 MPa)?

Yes: Use Grade 5 (Ti-6Al-4V, AMS 4928) — 130 ksi (896 MPa) UTS.

No: Continue to question 3.

3. Does the application require titanium's corrosion resistance (marine, chemical, medical)?

Yes: Use Grade 2 (CP titanium, ASTM B348) — lower cost, faster machining.

No: Reconsider whether titanium is the correct material at all. 304 stainless or 6061 aluminum may be more economical.

Key Takeaway

Most engineers default to Ti-6Al-4V Grade 5 for everything titanium. This is often an over-specification. If the structural FOS is well above 2.0 and the application is corrosion-dominated (not strength-dominated), Grade 2 reduces total part cost by 25–35% with no functional compromise.

Grade Summary

The Three Grades You Need to Know

Corrosion-first, cost-effective

CP Grade 2

ASTM B348 Grade 2

UTS50 ksi (345 MPa)

Machinability~30%

Material cost$10–18/lb ($22–40/kg)

Commercially pure titanium — the most machinable and most cost-effective titanium grade. Choose when corrosion resistance is required but the part is not load-bearing or high-stress.

The workhorse alloy

Grade 5 (Ti-6Al-4V)

AMS 4928

UTS130 ksi (896 MPa)

Machinability~22%

Material cost$15–30/lb ($33–66/kg)

The most widely used titanium alloy — over 50% of all titanium parts. Choose when both high strength and corrosion resistance are required: industrial, structural, and performance applications.

Medical implant grade

Grade 23 (ELI)

ASTM F136 / ISO 5832-3

UTS120 ksi (827 MPa)

Machinability~22%

Material cost$20–40/lb ($44–88/kg)

Extra Low Interstitials variant of Ti-6Al-4V with higher fracture toughness (KIc ~75 MPa√m). Required for load-bearing implantable medical devices. Not interchangeable with Grade 5 for regulated applications.

Grade Selection

Titanium Grade Decision Matrix

Decision matrix for selecting titanium grade for CNC machining
Requirement	CP Grade 2	Grade 5 (Ti-6Al-4V)	Grade 23 (ELI)
UTS > 100 ksi (690 MPa)	✗ (50 ksi / 345 MPa max)	✓ (130 ksi / 896 MPa)	✓ (120 ksi / 827 MPa)
Corrosion resistance (seawater)	✓ Excellent	✓ Excellent	✓ Excellent
Biocompatibility (ISO 10993)	✓	✓	✓
Load-bearing implant (ASTM F136 / ISO 5832-3)	✗	✗	✓ Required
Max service temp > 300°F (149°C)	✗	✓ (up to 600°F / 315°C)	✓ (up to 600°F / 315°C)
Lowest material cost	✓ $10–18/lb ($22–40/kg)	Moderate $15–30/lb ($33–66/kg)	✗ $20–40/lb ($44–88/kg)
Highest machinability	✓ ~30%	~22%	~22%
Best formability (cold bending)	✓ Excellent	Moderate	Moderate
Weldability (GTAW)	✓ Excellent	Good	Good
High-performance structural	✗ (insufficient strength)	✓	✗ (overkill for structural — use AMS 4928 Grade 5)
Standard availability	✓ Widely stocked	✓ Widely stocked	Specialty — longer lead

By Industry

Grade Selection by Industry

Industrial & Structural

Grade 5 (AMS 4928)

130 ksi (896 MPa) UTS + low density for high-performance brackets, machinery hardware, hydraulic fittings. STA condition (150+ ksi / 1,034+ MPa) for highest-strength applications.

Medical Implants

Grade 23 (ASTM F136)

Required for load-bearing implants per FDA guidance and ISO 5832-3 / ASTM F136. Grade 2 acceptable for non-load-bearing implanted components (check with regulatory counsel).

Marine & Offshore

CP Grade 2 (ASTM B348)

Corrosion immunity in seawater — chloride stress corrosion cracking does not occur in titanium. Grade 5 may be specified for structural components where strength matters.

Chemical Processing

CP Grade 2 (ASTM B348)

Superior resistance to reducing acids (HCl, H₂SO₄) where Grade 5 can suffer crevice corrosion. Reactor liners, piping, valves.

High-Performance Industrial

Grade 5 (AMS 4928)

Valves, compressor components, high-temp hardware. Grade 2 where corrosion is the sole concern.

Consumer / Sporting

Grade 5 (AMS 4928)

Bicycle components, eyeglass frames, watches, sports hardware. Grade 5 for structural; Grade 2 for jewelry/non-structural where machinability matters.

Cost Comparison

Grade Cost Comparison

Cost comparison for titanium grade selection
Cost Factor	CP Grade 2	Grade 5	Grade 23
Bar stock $/lb ($/kg)	$10–18 ($22–40)	$15–30 ($33–66)	$20–40 ($44–88)
Relative machining time	0.8×	1.0× (baseline)	1.0×
Material availability	Widely stocked	Widely stocked	Specialty (2–6 wk lead)
Relative total part cost	~0.65–0.75×	1.0× (baseline)	~1.2–1.5×
When cost premium is justified	Never over Grade 2 for corrosion-only apps	When strength required	Medical implant regulatory compliance

Need Help Narrowing the Grade?

Upload your application, cert requirements, and loading notes. During quote review, we can compare Grade 2, Grade 5, and Grade 23 against strength, corrosion, and document needs before you lock the material callout.

Review Grade Options

Common Questions

Frequently Asked Questions

Related Resources

Titanium Grades Explained (1–5)

Full properties table for all titanium grades

Grade 23 vs Grade 5

ELI vs standard: composition, toughness, regulatory

Titanium CNC Machining Guide

Complete guide: grades, speeds/feeds, DFM, cost

Quote Titanium Parts in Any Grade

Grade 2, Grade 5, or Grade 23 ELI can follow very different cost, certification, and machining paths. Upload your drawing to compare vetted shop options and engineer-reviewed pricing typically within one business day.

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