Three steps, with no tang to break off afterwards. The drill and STI tap are the same as for a standard insert; only the installation tool is different.
Both types fit the same STI-tapped hole, so you can switch between them without changing the drill or tap.
Click your industry to see how tangless inserts are used.
What is a tangless wire threaded insert?
A tangless wire threaded insert, also called a tang-free insert or tangless helical thread insert, is a coil of diamond-profile stainless steel wire that creates a strong, wear-resistant internal thread, just like a standard insert, but without a drive tang. Instead of a tang, it has a small driver notch that the installation tool grips. Once fitted into an STI-tapped hole, its inner face forms a standard internal thread of the original size, so the normal bolt is used. Because nothing has to be broken off after installation, there is no loose tang left in the part.
How is a tangless insert installed without a tang?
The hole is drilled and tapped with a standard STI tap, exactly as for a tanged insert. A tangless installation tool is then used: its spring-loaded blade engages the driver notch on the insert and winds the coil into the tapped thread, usually up to a preset depth stop. When the tool is withdrawn, the insert stays in place, held by its own spring tension against the thread. There is no tang to break off, so installation is finished in one step. The tools can be used by hand or with a power driver, and we supply them on request.
What is the difference between tanged and tangless wire threaded inserts?
Both create the same strong internal thread in the same STI-tapped hole. A tanged insert has a drive tang across its end that the tool pushes against; after installation the tang must be broken off and removed. A tangless insert has a driver notch instead, so nothing is broken off, no loose debris is created, the insert can be backed out or repositioned with the tool, and it can be installed from either end. Tanged inserts offer the widest range of threads and lengths and use simpler tools; tangless inserts are chosen where loose debris is unacceptable, where parts are serviced often, or where installation is automated.
Why are tangless inserts preferred in aerospace and electronics?
In aerospace engines and gearboxes, a broken tang left inside the part is foreign object debris (FOD) that can damage moving parts. In electronics, a loose metal tang can cause a short circuit. Tanged inserts therefore need every tang to be found, removed and counted, which costs inspection time and still carries a risk. Tangless inserts have no tang at all, so the risk and the inspection step are removed completely. This is why they are widely used in aircraft, defence electronics, terminal blocks and enclosures.
Can a tangless insert be removed or repositioned?
Yes. The tangless installation tool can engage the driver notch again and wind the insert further in or back it out, without damaging the STI-tapped thread or the parent material. An insert set at the wrong depth can be corrected in seconds, and a damaged insert can be taken out and a new one fitted in the same tapped hole. This makes tangless inserts well suited to parts that are maintained, overhauled or repaired many times.
Can a tangless insert be installed from either end?
Yes. Tangless inserts have driver notches at both ends, so there is no right way round. The operator does not need to check the orientation of each insert before fitting it, which saves time in manual assembly and makes tangless inserts well suited to automatic and semi-automatic installation on the production line.
Do tangless inserts need a different tap or drill?
No. Tangless inserts fit the same STI-tapped hole as standard tanged inserts, so the same drill and the same STI tap are used. Only the installation tool is different, because it must grip the driver notch instead of a tang. This also means you can switch an existing design from tanged to tangless inserts without changing the hole preparation.
Are tangless inserts as strong as tanged inserts?
Once installed, a tangless insert sits in the same STI-tapped hole and gives the same internal thread form and the same engagement with the parent material as a tanged insert of the same size and length. The load a joint can carry depends mainly on the parent material, the insert length and the bolt grade, so the insert length should be chosen from your joint design. For safety-critical joints, confirm performance against your own specification or test requirements before switching insert type.
Which threads, lengths and materials of tangless inserts do you supply?
Excel Trading Corporation supplies tangless free-running wire threaded inserts in metric coarse threads, with UNC and UNF available on request. Lengths are 1D, 1.5D and 2D, where D is the nominal thread diameter. Inserts are available in SS 304, the standard material for most applications, and Nitronic 60, a high-performance stainless steel chosen for galling and wear resistance and elevated temperature. Other materials, tangless installation tools, STI taps and test certificates are available on request.
Where can I buy tangless wire threaded inserts in Bangalore or India?
Excel Trading Corporation supplies tangless free-running wire threaded inserts in SS 304 and Nitronic 60 from Bengaluru to OEMs across India, along with tangless installation tools and STI taps on request. Lead time is confirmed on enquiry. Use the Request a Quote button on this page, call +91 7204435253 or email info@exceltrading.in with the thread size, length, material and quantity you need.
