Knowing what titanium is and knowing where to specify it are two different problems. This one is the second. Titanium applications are not spread evenly: a handful of industries consume almost all of the tonnage, and each of them draws on a different product form. Get the form wrong and you pay for machining that should have been a welded plate, or for a casting that a bar would have covered.

Two factors settle nearly every selection. The first is the medium — titanium is close to inert in seawater, chlorides, nitric acid and hypochlorite, and unsuitable in hydrofluoric acid or any fluoride-bearing stream. The second is the form: titanium is bought as mill product, as a machined component, or as a sintered porous body, and each route carries its own specification logic, inspection class and lead time. The underlying metallurgy — grades, properties and the Kroll process — is covered in what titanium is.

1. Where Titanium Is Used: Seven Industries

Titanium consumption splits roughly into aerospace and everything else, and the “everything else” is growing fastest because of the energy transition. The seven industries below account for almost all volume.

Aerospace

Airframe structures, engine fan blades and disks, fasteners, landing gear components and hydraulic tubing. Ti-6Al-4V dominates, with Ti-6Al-2Sn-4Zr-2Mo for hotter compressor sections and Ti-3Al-2.5V for tubing. The driver is weight saved per unit of strength at temperature.

Medical devices

Dental implants, hip and knee stems, bone plates, spinal cages and surgical instruments. Grade 4 CP titanium and Grade 23 ELI are the two standard choices; porous titanium coatings and 3D-printed lattice structures are used to match bone stiffness and reduce stress shielding.

Chemical and petrochemical processing

Heat exchangers, reactor internals, columns, pumps and valves handling nitric acid, chlorine, hypochlorite and organic acids. Grade 7 or Grade 12 enters the picture wherever reducing conditions appear. Industrial titanium plate is the standard starting point for vessel and exchanger fabrication.

Seawater and desalination

Multi-stage flash and multi-effect distillation plants use titanium tube bundles, water boxes and brine heaters. Thermal desalination is arguably the single application where titanium’s cost is easiest to justify — a copper-nickel tube bundle that fails in five years costs more than a titanium bundle that lasts thirty.

Energy: electrolysers and fuel cells

This is the fastest-moving segment. Proton exchange membrane (PEM) electrolysers use porous titanium as the porous transport layer (PTL) and as bipolar plates, because the anode side runs at low pH, high potential and high oxygen concentration simultaneously — an environment carbon and stainless steel cannot survive. Design guidance for pore size, porosity and thickness is covered in our guide to titanium PTL design for PEM electrolysers.

Marine, offshore and consumer

Subsea hardware, seawater piping, yacht fittings, dive equipment, watch cases, eyewear frames, bicycle frames, camping cookware and cutlery. Consumer demand is what keeps titanium in the public vocabulary — and it is a genuine market, not a novelty.

Architecture and infrastructure

Roof and façade panels, especially in coastal and heavily polluted cities, where the metal is specified for a 100-year surface life with no repainting.

2. Titanium Mill Product Forms: Plate, Bar, Tube, Foil and Wire

Most titanium enters a plant as mill product and is fabricated on site. The form is chosen by the fabrication route, not by preference: welded vessels want plate, machined parts want bar, heat exchangers want tube, and anything that will be cold-formed wants thin strip or foil.

Above: turned and ground titanium bar in a range of diameters. Bar is the starting stock for almost every machined titanium component — flanges, bushings, bolts, valve internals and orthopaedic stems.

Bar is ordered by diameter, straightness, surface condition and ultrasonic inspection level. For general machining stock Grade 2 covers most chemical and marine work; Grade 5 is specified where the finished part carries structural load or sees elevated temperature.

Plate and tube carry the bulk of titanium tonnage because they carry the bulk of the surface area. Tube bundles in seawater-cooled heat exchangers, plate in vessel shells and tube sheets, and clad plate where a titanium face is bonded to a carbon steel backing to cut cost. Our comparisons of sheet versus plate, bar and rod specifications and tube and pipe selection go through the dimensional and specification differences that matter at the drawing stage.

Above: titanium wire supplied as coil and as straight cut lengths. Wire is drawn from rod, and the drawing schedule — not the chemistry alone — usually decides whether the finished wire can be bent and woven without cracking.

Wire feeds three distinct uses: welding filler for titanium fabrication, woven mesh and knitted structures for filtration and mist elimination, and electrodes for electrochemistry and medical devices.

Foil is the form most often overlooked. At 0.01–0.1 mm, titanium foil is used for precision-formed diaphragms, electrode substrates and cladding layers, and it is produced by cold rolling with intermediate annealing because titanium work-hardens so quickly that a single pass would crack the strip.

3. Machined and Fabricated Titanium Components

A growing share of titanium is bought as a finished part rather than as stock. Two routes dominate: CNC machining from bar or plate, and fabrication by welding and forming from sheet, tube and wire.

Machining titanium is a different discipline from machining stainless steel. The metal conducts heat poorly, so cutting heat stays in the tool edge instead of leaving with the chip. It work-hardens, so any dwell in the cut hardens the surface faster than the tool can shear it. And it is chemically reactive at cutting temperature, which is why titanium fines can ignite. The practical rules are low surface speed, high feed, generous coolant and sharp tooling that never rubs. Shops that machine titanium daily hold ±0.01 mm routinely, but cycle times typically run two to three times those for 316L — a cost that has to be designed in from the start.

Fabrication is shaped by the same reactivity. Titanium welds must be shielded from air until the weld cools below roughly 400 °C, which means a trailing shield and, for anything complex, a purge chamber. That is why titanium fabrication concentrates in shops that already own the argon equipment rather than spreading across general welders.

Above: machined titanium components — a CNC-turned flange, a blank disc, a threaded bolt and a bushing, all produced from titanium bar.

Typical machined parts include heat exchanger tube sheets, pump and valve internals, electrode plates, implant stems, spacer rings and fasteners. Where the part is also a flow path — a filter housing or an electrode frame — machining and sintering are often combined in the same component.

Where the finished part is a flow device rather than a structural one, machining alone is usually the wrong answer: sintered porous titanium gives a controlled pore structure that no machining operation can produce. That is the form most industrial buyers actually source, and it is covered next.

4. Porous and Sintered Titanium: The Form Most Buyers Actually Source

Beyond mill products — sheet and plate, bar and rod, tube and pipe, wire and foil — a large share of industrial titanium is used in sintered, porous form. Titanium powder or titanium fibre is pressed and vacuum-sintered into a body with 30–50% open porosity, giving a structure that is simultaneously a structural component, a flow path and a filter medium.

Above: a 20 μm sintered porous titanium plate used as a PTL in PEM water electrolysis. Pore size, porosity, thickness and surface roughness all have to be specified together — changing one shifts gas transport and contact resistance.

The same sintering route produces filtration elements with a defined absolute pore rating, which is why porous titanium is used where a filter must survive steam sterilisation, aggressive chemistry or repeated backflushing.

Sintered and porous titanium products fall into four families:

• Powder-sintered elements — discs, tubes, candles and cartridges with pore sizes from roughly 0.5 μm to 100 μm. Used for fine filtration in chemical, pharmaceutical and food processing.
• Titanium fibre felt and fibre paper — higher porosity at the same pore size than powder sintering, which means higher permeability. Preferred as PTL and GDL substrates in electrolysers and fuel cells.
• Sintered multi-layer mesh — a stack of woven mesh layers sintered into a rigid sheet, giving high strength and controlled pore distribution for high-pressure filtration.
• Spargers and gas diffusers — porous titanium that turns gas into a fine bubble stream for aeration, ozonation and dissolved-gas dosing, taking advantage of titanium’s corrosion resistance in oxidising water.

Two sourcing points matter here. First, pore rating must be quoted as absolute, not nominal — a “10 μm” nominal rating can pass particles well above 10 μm, which is unacceptable for sterile filtration. Second, porosity and pore size trade off against mechanical strength: a 45% porosity element is more permeable but weaker under differential pressure than a 30% one. Getting that balance right for a given duty is the core of the specification, and it is covered in detail in our complete guide to titanium sintered filters.

Above: a sintered titanium rod filter cartridge. The sintered metal body can be cleaned and regenerated by backflushing, ultrasonic cleaning or chemical cleaning, and reused many cycles — which is usually what makes the titanium option cheaper than a disposable element over a full service life.

Cartridges are supplied in standard connector formats so they drop into existing housings, from single-element lab units to multi-round industrial assemblies.

5. How to Choose Titanium for Your Application

Five questions settle most titanium selections. Work through them in order and the grade and form usually fall out on their own.

1. Is the medium actually aggressive? If it contains fluorides, titanium is out. If it is seawater, chloride brine, nitric acid or hypochlorite, titanium is a strong candidate. If it is a mild reducing acid, look at Grade 7 or 12 before ruling it in or out.
2. What temperature does it see? CP titanium is fine to about 315 °C continuous; above that, oxidation and creep start to matter and an alloy is needed. Cryogenic service favours low-interstitial grades such as Grade 23.
3. Strength or formability? Deep drawing and cold forming want Grade 1. General industrial fabrication wants Grade 2. Load-bearing structure wants Grade 5 or 4.
4. What is the product form? Mill products (plate, bar, tube, foil, wire) come from the titanium materials range. Porous and sintered parts — PTL substrates, filter elements, spargers — are in the PTL and porous titanium plate range.
5. What is the total cost of ownership? Compare against two or three replacement cycles of the cheaper material, not against its purchase price. This is where titanium usually wins and where a pure price comparison misleads.

Above: the forms TOPTITECHS supplies — sponge and ingot as melt feedstock, tube, plate and bar as mill products, wire and woven mesh for fabrication, and a sintered porous disc for filtration and electrolysis.

Matching the form to the fabrication route is usually the last decision made and the one that sets lead time. Sponge and ingot are quoted on chemistry, mill product on specification and inspection class, and sintered parts on pore rating, porosity and finished dimensions.

Common starting points: titanium sponge for melting feedstock, titanium plate for vessel and heat-exchanger fabrication, titanium bar for machining and fastener stock, titanium machining parts for finished components, sintered titanium filter cartridges for chemical and pharmaceutical filtration, and porous titanium plate for electrolyser stacks and gas diffusion layers.

6. Frequently Asked Questions