V-COIL rapid STI-Twist Drill, 4.2 mm

• Preparing the core hole before STI tapping in a wire thread insert repair process
• Supporting a repair workflow where the receiving hole must match the insert system logic before tapping starts
• Using a defined drill stage before insert based restoration of an internal thread
• Process: manual driving or assisted driving depending on your holder and machine setup
• Use: thread cutting, re tapping, and thread cleaning depending on condition

Note Select the product by thread designation, workpiece condition and the holder concept used in your process.

• Matched repair logic supports repeatable restoration of an existing thread designation
• Insert based repair can improve service life of the receiving thread in repeated assembly work
• Suitable for maintenance, overhaul and workshop repairs where part replacement is undesirable
• Clear assignment between preparation, tapping and insert installation reduces handling errors

• The process depends on the correct repair sequence and is not suitable when the parent material is cracked or too thin for the repair concept.
• It is a repair system and not the fastest choice when you only need a one time emergency fix without the full preparation steps.

1. Prepare the workpiece and confirm the correct thread designation before use.
2. Mount the tool securely in the intended holder or machine interface.
3. Align the product to the thread axis and start the operation in a controlled manner.
4. Continue the process with stable guidance and suitable lubrication.
5. Remove the tool carefully and clean the work area after the operation.
6. Protect the product from impact and contamination before storage.

• 1 piece V-COIL rapid STI-Twist Drill, 4.2 mm

• Product type: STI preparation drill
• Drive or handling concept: hexagon drive

What do you use V-COIL rapid STI-Twist Drill, 4.2 mm for?

You use this product when an internal thread must be restored, reinforced or prepared within a wire thread insert repair process. The exact role depends on whether the product is the kit, the insert, the STI tool or the installation accessory.

Where can you find more technical background?

For additional technical background, see Technical information V-COIL thread repair as PDF.

What is STI in this repair context?

STI refers to the receiving thread used for wire thread inserts, so the preparation tool must match the insert system rather than a normal direct fastening thread.

Where can you find one more related technical reference?

For a second related reference, see Technical information tapping drill sizes V-COIL as PDF.

What should you check before assembly after repair?

Check that the repaired thread is clean, the insert sits correctly when applicable and the mating fastener engages smoothly without cross threading.

Where can you find the catalog entry for this product group?

For catalog level orientation, see VC 23 catalog as PDF.