Titanium Grade 2 vs Grade 5 for EDC parts
Grade 2 anodizes into deeper colour, Grade 5 holds threads. Which titanium to specify for knife scales, pen bodies and flashlight parts — and what each costs to machine.
Almost every EDC project that comes through us starts with the same unanswered question on the drawing: it says titanium, and nothing else. That single word covers two alloys that machine differently, cost differently and finish differently, and picking the wrong one is the most common reason a first prototype comes back looking right and performing wrong.
The short version
Grade 2 is commercially pure titanium. Softer, more ductile, and it anodizes into deep, saturated colour — the purples and blues people associate with premium titanium hardware. Grade 5, Ti-6Al-4V, is alloyed with aluminium and vanadium. Roughly twice the strength, holds threads and screw bosses without stripping, and anodizes to a flatter, slightly chalkier version of the same colours.
If the part carries load, specify Grade 5. If the part’s job is to look extraordinary and it is screwed to something else that takes the force, Grade 2 is the better-looking choice.
Where it actually matters
| Part | Specify | Why |
|---|---|---|
| Frame-lock liner | Grade 5 | The lockbar flexes thousands of times; Grade 2 takes a set |
| Show-side knife scale | Grade 2 | No load, and the anodize colour is the whole point |
| Pen barrel with threaded cap | Grade 5 | Threads in Grade 2 wear visibly within a year of daily use |
| Pen barrel, press-fit sections | Grade 2 | Deeper colour, no thread to protect |
| Flashlight head and tail threads | Grade 5 | Repeated make-and-break; galling risk in pure titanium |
| Beads, worry stones, bottle openers | Grade 2 | Colour-led, load-free, and it machines faster |
| Pocket clips | Grade 5 | Springs back instead of bending out permanently |
What each costs to machine
Grade 2 machines faster and easier on tooling, but the material is only slightly cheaper than Grade 5, so on a small batch the cost difference is smaller than buyers expect — usually five to twelve percent at the quantities EDC runs at. Below about fifty pieces, setup and finishing dominate the quote and the alloy choice barely moves the total.
Both alloys are slow compared to aluminium. Titanium’s low thermal conductivity pushes heat into the tool rather than into the chip, so surface speeds stay low and tools wear fast. A shop quoting titanium at aluminium-like cycle times has either not machined much of it or has not read the drawing.
The anodizing catch
Titanium anodizing is an interference effect: an oxide layer grown to a precise thickness by holding a precise voltage, which makes the colour. Grade 2’s purer surface grows a more even layer, which is why its colours look deeper.
The bigger variable is not the alloy, it is the fixture. A shop that racks parts loosely gets voltage drop across the batch and a visible drift from bronze to brown across what should be one colour. Ask for a five-piece colour sample before committing a production run, whichever grade you picked. That single request prevents more reorder disputes than any tolerance callout.
Practical rule
Write the grade on the drawing, not the word “titanium”. If you genuinely do not know which one the part needs, say what the part does — “this liner is the lock face” — and any competent shop will tell you. Send the drawing and we will flag it before it gets quoted.
Composition and properties
| Grade 2 (CP Ti) | Grade 5 (Ti-6Al-4V) | |
|---|---|---|
| Composition | Commercially pure titanium | 6% aluminium, 4% vanadium |
| Yield strength | ~275 MPa | ~830 MPa |
| Tensile strength | ~345 MPa | ~900 MPa |
| Hardness | ~80 HRB | ~36 HRC |
| Density | 4.51 g/cm3 | 4.43 g/cm3 |
| Machinability | Better | Harder, more tool wear |
| Anodize saturation | Deeper | Flatter |
| Relative cost | Slightly lower | Slightly higher |
The strength difference is the headline: Grade 5 is roughly three times stronger in yield. That is why it appears anywhere a thread, a spring or a lock face takes load.
Note that density is essentially the same. Choosing Grade 5 does not make a part lighter — it lets the same part be thinner for the same strength, which is a different thing and worth phrasing correctly in product copy.
Machining differences in practice
Both are slow compared to aluminium, and for the same reason: titanium’s low thermal conductivity means heat stays in the cutting zone rather than leaving with the chip. That is what limits surface speed and kills tools.
Grade 5 is worse than Grade 2 on both counts. Expect longer cycles and shorter tool life, which on a small batch is a real cost since tooling is amortised across few parts.
Practical requirements either way: rigid workholding, sharp tooling, generous coolant, and no dwelling. A tool that rubs instead of cutting work-hardens the surface and the next pass is cutting harder material.
Shops that run titanium weekly have this sorted. Shops that do not will produce a poorer finish, quote a longer cycle, or both. It is a reasonable question to ask directly.
Galling
Titanium against titanium galls readily — the surfaces cold-weld under load and tear. That matters for any threaded joint operated regularly: a pen cap, a flashlight tail, a knife pivot with a titanium bushing.
Grade 5 resists it better than Grade 2, which is one more reason threads go in Grade 5. Full mitigation means anodizing both halves, introducing a dissimilar material, or accepting visible thread wear. See flashlight threads and titanium pen machining.
Availability in Vietnam
Grade 5 plate and bar in common sizes is routinely stocked. Grade 2 is available but in a narrower range of thicknesses, and unusual sections in either grade can carry a two to three week material lead time.
If your design depends on a specific plate thickness, raise it in the RFQ. Material lead time is frequently the longest single item in an EDC schedule and it is invisible until someone checks.
Other grades you may encounter
Grade 1 is softer and more formable than Grade 2, and anodizes similarly. Rarely stocked for this work.
Grade 9 (Ti-3Al-2.5V) sits between 2 and 5: stronger than Grade 2, easier to work than Grade 5. Common in tubing, occasionally useful for a pen barrel.
Grade 23 (Ti-6Al-4V ELI) is the extra-low-interstitial medical version of Grade 5. More expensive with no benefit for EDC. Do not specify it by accident.
If a listing says “implant grade”, read what the claim needs.
FAQ
Which grade for a knife scale? Either. Grade 5 if it carries the lock or takes screws under load; Grade 2 if it is a show-side cover panel and the anodize colour is the point.
Can I anodize Grade 5 the same colours as Grade 2? The same hues, less saturated. Side by side the difference is visible. See titanium anodizing colours.
Is Grade 5 much more expensive? The material is modestly more expensive; the machining is meaningfully slower. At small batch sizes setup dominates both, so the total difference is often five to twelve percent rather than the large gap people expect.
Does titanium need heat treatment? No, not for EDC use. It arrives in the condition you want. See heat treatment for EDC parts for the grades that do.
Is titanium hypoallergenic? Titanium is widely used in implants and body jewellery and is well tolerated. Grade 5 contains aluminium and vanadium, which is why Grade 23 exists for medical implants — not a consideration for a pocket-carried item.
What should I write on the drawing? The grade, explicitly: “Ti-6Al-4V (Grade 5)” or “CP Ti Grade 2”. Never just “titanium”. Send the drawing and if the grade is wrong for what the part does, we will say so before it is quoted.