What are Titanium Threaded Inserts?

Titanium threaded inserts, also known as titanium inserts, are self tapping Tappex Trisert-3 inserts made from Grade 5 titanium, forming part of Accu's threaded inserts range and giving light alloy, composite and plastic parts a strong, corrosion resistant thread at around half the weight of stainless steel. Each is a short cylinder with a metric internal thread, a truncated external thread broken by three curved cutting facets and a thin reduced head at the top. Those facets cut a clean mating thread as the insert is driven into a plain hole and the titanium body keeps that thread free from corrosion in seawater and other harsh environments.

Every insert is made from Ti-6Al-4V by Tappex in Stratford-upon-Avon and supplied with a Certificate of Conformity and RoHS certification. The combination of low weight and corrosion resistance suits aerospace components (including 3D printed parts), marine fittings, automotive and rail assemblies and motorsport, where every gram counts.

How Titanium Threaded Inserts Work.

A titanium threaded insert goes into a plain moulded or drilled pilot hole and is driven through its own internal thread, using a tool that engages the thread so installation torque can be controlled. As it turns, the three cutting facets share the cutting load evenly and form a mating thread in the host, while the solid, unslotted body and fully supported cutting edges keep their shape in harder materials. Once seated, the truncated external thread resists back-out and the reduced head gives the mating part a large bearing surface. The result is a free-running metal thread in aluminium, magnesium, glass-filled plastics or composites, with no tapping step.

Take a carbon fibre bodywork panel on a motorsport chassis, fixed with M5 screws that come out every time the car is serviced between sessions. A thread tapped straight into the composite wears quickly under that kind of repeated assembly. A titanium Trisert-3 installed in a pilot hole gives each screw a metal thread at around half the weight of a stainless steel insert, a saving that adds up across the dozens of fixings on a car and the same insert in an aluminium hatch frame on a boat keeps its thread clear of corrosion in salt spray.

Materials Titanium Threaded Inserts Are Made From

Accu's titanium range is made from a single high-performance alloy, chosen for the strength, weight and corrosion resistance that demanding environments call for:

• Titanium - (Grade 5): Ti-6Al-4V, which Tappex quotes at a strength of 950 MPa and a density of 4.43 g/cm³, roughly half that of 316 stainless steel. On exposure to air it forms a stable, inert oxide film, which is why it does not corrode in normal seawater or in polluted harbour water.

Every insert is supplied Clear Passivated, a chemical treatment that cleans the surface and supports that natural oxide layer.

Sizes & Types of Titanium Threaded Inserts Available

The range is available in four metric thread sizes, each in two lengths:

• Insert Type: Trisert-3.
• Installation Method: Self Tapping.
• For Use With: Wood, Plastic & Non-Ferrous Metal (Requires Pilot Hole).
• Internal Thread Size: M3 (3 mm) to M6 (6 mm).
• Length (L): 5.25 mm to 12 mm.
• Outer Diameter (OD): 4.73 mm to 8.69 mm.
• Recommended Hole Size (HS): 4.1 mm to 8.4 mm.
• Flange Diameter (FD): 4.7 mm to 8.6 mm.
• Flange Length (FL): 0.38 mm to 0.45 mm.

Each thread size comes in a regular length (part numbers beginning 6238) and a long length (beginning 6270), from 5.25 mm or 6.25 mm at M3 up to 9.8 mm or 12 mm at M6. Every insert has the reduced head and the range covers M3 to M6 only. The Recommended Hole Size (HS) at each size matches the equivalent brass Trisert and stainless Trisert-3, so switching to titanium does not change the hole.

Where weight is less critical, Trisert-3 in Stainless Steel - Marine (A4) or Stainless Steel - (303) is the alternative for corrosive environments and Stainless Steel - (A2) Self Tapping inserts run up to M20 for larger threads. Both are in Accu's Threaded Screw Inserts range.

FAQ

Q: Why choose titanium threaded inserts over stainless steel?

A: Weight and corrosion resistance. Grade 5 titanium inserts weigh around half as much as the same insert in 316 stainless steel while offering high strength. Tappex positions titanium as having better corrosion resistance than stainless, with no corrosion in normal seawater or polluted harbour water. Where weight does not matter, the stainless steel Trisert-3 covers most corrosive environments.

Q: What can titanium inserts be installed into?

A: They are specified for wood, plastic and non-ferrous metal and Tappex designed Trisert-3 for light alloys such as aluminium and magnesium, glass-filled thermoplastics and hard thermosets, including those reinforced with carbon or aramid fibre. Steel and cast iron fall outside that specification.

Q: How large a boss does a titanium threaded insert need?

A: Tappex gives a minimum boss diameter of 7.7 mm at M3, 10.7 mm at M4, 12.6 mm at M5 and 14.7 mm at M6. Treat these as guidance and test in the actual part before committing to production, because the right figure depends on the grade of the host material.

Q: Do titanium inserts need a different hole size?

A: No. They share the Recommended Hole Size (HS) of the brass Trisert and stainless Trisert-3: 4.1 mm to 4.4 mm at M3, 5.8 mm to 6.1 mm at M4, 6.9 mm to 7.2 mm at M5 and 8 mm to 8.4 mm at M6. Tappex publishes slightly larger holes for light alloys than for plastics, so confirm the figure for the host before drilling.

Q: How is a titanium threaded insert installed?

A: It is driven in through its own internal thread with a hand tool or a torque-controlled driver, so the hole never needs tapping. Alignment matters more as the host gets harder: keep the insert square to the hole from the first turn, because an insert started at an angle cuts a crooked thread.

Q: Are titanium inserts magnetic?

A: No. Ti-6Al-4V is non-magnetic, which makes titanium inserts a useful choice near sensors, compasses and other equipment sensitive to magnetic fields, as well as in the marine and aerospace assemblies where their weight and corrosion resistance are the main draw.

Bespoke Titanium Threaded Inserts Manufacture.

High precision, bespoke manufacture of Titanium Threaded Inserts to customer specification. State of the art facilities specialising in both small batch prototyping and large scale manufacture.