STI HexTap for installation of solid thread inserts for M18x1.5 oxygen sensor thread HSS-G - M 18 x 1.5

The abbreviation STI stands for "Screw Thread Insert". An STI tap is a specialized tool that does not cut the final thread size like a conventional tap. Instead, it cuts an oversized thread into a pre-drilled hole. A solid thread insert (often a wire coil) is then screwed into this oversized thread. This thread insert then creates the new, correct, and durable thread in the original nominal size (in this case M 18 x 1.5). This procedure is the first choice when the original thread is damaged and a durable repair is required, as is often the case with oxygen sensor threads.

The V-COIL STI HexTap is intended for use in well-machinable materials up to 900 N/mm², including unalloyed and low-alloy steels.

Follow these steps to precisely repair or clean an oxygen sensor thread:

1. Preparation: Drill the damaged oxygen sensor thread to the core diameter suitable for the tap. Use a drill bit with the diameter specified by V-COIL. The hole must be clean and deburred. For simple thread cleaning, drilling is not necessary.
2. Clamping: Thanks to the Multi-Drive drive (internal square 6.3 mm and external hexagon 14 mm), you can use the HexTap with either a ratchet, an angled screwdriver, or an open-end wrench. Choose the most suitable tool for your working area.
3. Cutting: Cut the STI thread into the prepared hole. Make sure to guide the tool straight to ensure a clean cut. Use cutting oil to minimize friction and extend the tool's life.
4. Insertion: After cutting, the thread insert bushing is screwed into the STI thread using the appropriate tool (installation spindle or insertion tool).
5. Completion: The new, repaired oxygen sensor thread is now ready for the oxygen sensor.

1. What makes this tap particularly suitable for oxygen sensors?

The STI HexTap is specifically designed for the M18x1.5 thread of oxygen sensors. The combination of STI technology and robust construction makes it ideal for the demanding repair of threads in this application area.

2. What is the advantage of the Multi-Drive drive?

The Multi-Drive drive with an internal square and external hexagon offers maximum flexibility. You can use it with a ratchet in tight spaces, an angled screwdriver for precise guidance, or an open-end wrench for higher torque, making it ideal for various work situations.

3. Can I use this tool for a normal M18x1.5 thread as well?

No, the STI HexTap cuts an oversized thread that is only intended for holding thread inserts. A normal M18x1.5 screw thread would not hold in this hole. It is exclusively for repair purposes in conjunction with V-COIL bushings.

4. What does the tolerance ISO 2 / 6H mean?

Tolerance class 6H is a standard tolerance for metric ISO threads. In the context of this tool, it ensures that the thread insert fits perfectly with an oxygen sensor that has the standard tolerance field.

5. Is this tool also available in sets?

Yes, the V-COIL STI HexTap is also available in complete thread repair kits, which include the tap as well as suitable thread inserts and installation tools.