Titanium Machinability

Titanium is harder to machine than general steels and stainless steels [1]. It conducts heat poorly and keeps its strength when hot, so heat and cutting force concentrate at the cutting edge [1]. It sticks to the tool and forms built-up edge [3][4], and it flexes more than other metals [3]. The tooling makers’ advice is consistent: a rigid setup, positive-rake carbide tools, lower speeds with higher feeds, and plenty of high-pressure coolant [1][2][3].

Why titanium is hard to machine

Heat stays at the edge. Titanium has poor thermal conductivity and retains its strength at high temperature, which generates high cutting forces and heat at the cutting edge [1]. A 2023 peer-reviewed review names high strength, low thermal conductivity and high chemical reactivity as the core problems [5]. Temperatures in the cutting zone can reach 1000 °C [4]. That is an upper figure, not a typical one.
It reacts with the tool. A cutting speed that is too high produces a chemical reaction between the chip and the tool material [1]. The affinity between titanium and tool materials produces built-up edge, which changes the tool’s geometry [4]. The three dominant wear mechanisms are adhesion, abrasion and diffusion [5].
It galls. Built-up edge, notching at the depth-of-cut line, galled workpieces and chips welding to the cutter are the main failure modes [2].
It flexes. Titanium is less rigid than other metals, so it needs a secure grip and as rigid a machine setup as possible [3].
Rubbing work-hardens it. A tool stopped against a profiled wall rubs, which creates excess heat and work-hardens the material [3].

Commercially pure grades vs Grade 5

	Commercially pure, Grades 1–4	Grade 5 (Ti-6Al-4V)
What it is	Unalloyed titanium, graded by strength [3]	Alloyed with 6% aluminum and 4% vanadium [3]
Specified minimum tensile strength, annealed (ASTM B348)	240 MPa (Grade 1) to 550 MPa (Grade 4)	895 MPa
How it machines	Softer and gummier; galling is the big concern [3]	Alloying raises hardness [3]

Ti-6Al-4V type alloys account for the majority of titanium alloys in use [1]. Full limits for every grade are in the titanium grades chart.

The right speeds and feeds depend on the operation, the tool and the grade. These are the published starting points, with their sources.

Area	Recommendation	Source
Machine	Machine titanium only on rigid equipment	[2]
Tool	Positive, open geometry with good edge toughness; fine-grained uncoated carbide is usual	[1]
Tool	Positive rake, tough substrate, hard lubricious coating	[2]
Speed	60 m/min roughing, 3–4 times that for finishing	[2]
Speed	Commonly under 90 m/min (peer-reviewed review)	[5]
Feed	Keep speeds down and feeds up	[3]
Feed	If the setup can take the load, raise the feed to push heat into the chip	[2]
Coolant	Plenty of coolant at high pressure	[3]
Coolant	Concentration 10% or more, a pump of at least 500 psi, filtration to 25 microns or better	[2]
Toolpath	Trochoidal paths with constant cutter engagement	[2]
Toolpath	Don’t stop the tool against a wall; keep it moving	[3]

The two speed figures differ because they describe different things. Sandvik splits roughing from finishing [2]; the review gives a general figure [5].

Chips and fines are a fire hazard

Fine titanium particles ignite easily in air [6]. Titanium fines and powders carry a flammability hazard rating of 3 or 4 on a 0–4 scale [6].
Airborne metal dust can explode when confined in a vessel or building [7].
Store open piles of chips and fines apart from other metal scrap so a fire can’t spread [6]. That is the NFPA 484 requirement the Chemical Safety Board quotes.
Class D sodium chloride extinguishers are meant for titanium fires. Water on burning titanium can react at high temperature to produce explosive hydrogen gas [6].

Follow NFPA 484 and the safety data sheet for your material.

Buying titanium to machine

Laube supplies titanium bar, tube, sheet and plate in Grades 1, 2, 3, 4, 5, 9 and 23. Bar and tube are cut to length in-house, and every order ships with its mill test certificate. Request a quote with the grade, size and quantity you need.