Thread Repair Workshop Kit UNF 1/4 – UNF 1/2

The V-COIL system is based on thread inserts made of stainless steel (Type S - free running according to DIN 8140, tolerance ISO 2 (6H)), which represent a superior alternative to conventional thread repair methods.

Your advantages at a glance:

• Higher Thread Load Capacity After Repair: The elastic stainless steel thread inserts distribute the load more evenly across the thread, often exceeding the strength of the original thread, especially in materials with low shear strength like aluminum or magnesium.

• Corrosion and Temperature Resistance: The stainless steel inserts offer excellent protection against corrosion and withstand high temperatures, extending the lifespan of the repaired connection.

• Cost-Effectiveness: By salvaging rejected parts and improving thread longevity, you reduce your manufacturing and repair costs in the long run. The kit's favorable price makes the investment quickly pay off.

• Flexible Readiness for Use: The kit includes more inserts and spiral drills for the most common UNF dimensions from 1/4" to 1/2". This ensures you're well-equipped for a variety of repairs.

• Optimized for Manual Use: The included STI taps, installation tools, and tang breakers are specially designed for easy and precise handling.

• Attractive and Functional Packaging: All components are neatly organized in an appealing and robust package, significantly simplifying handling in daily work.

• Thread Repair: Perfect for quick and reliable repair of damaged or worn threads in all materials, from metals to plastics.

• Thread Reinforcement: Ideal for strengthening threads in soft materials with low shear strength. The stainless steel inserts increase pull-out strength and enable high-strength connections.

• Reclaiming Rejected Parts: You can easily repair expensive workpieces with faulty threads instead of discarding them as scrap.

• Creating High-Strength Threads: Also suitable for new designs to achieve durable and extremely robust threads from the outset.

Using the V-COIL thread repair kit is simple and requires only a few steps. The kit contains all the necessary tools:

1. Drill out the damaged thread:

   • Select the appropriate STI spiral drill bit from the kit, whose diameter exactly matches the thread to be repaired (e.g., for UNF 1/4", the 6.7 mm drill bit is included).

   • Carefully drill out the damaged thread. Ensure a straight drilling path to create an optimal base for the new thread.

2. Tap the thread for the insert:

   • Insert the corresponding STI single-pass tap (e.g., UNF 1/4 x 28) into your tap wrench or drilling machine.

   • Cut the receiving thread for the thread insert into the drilled hole. Since these are STI taps, they create a special oversized thread into which the V-COIL insert is screwed precisely. Always use sufficient cutting oil.

3. Insert the thread insert:

   • Select the appropriate thread insert (e.g., UNF 1/4 x 28 – 1.5 D) and the corresponding manual installation tool with locking ring (e.g., No. 9).

   • Place the thread insert onto the installation tool. The driving tang of the insert must engage with the slot of the installation tool.

   • Carefully and evenly screw the thread insert into the previously cut receiving thread until it is flush with the workpiece surface.

4. Break off the driving tang:

   • Once the thread insert is fully installed, the driving tang (the small pin used for screwing in) must be removed.

   • Place the appropriate tang breaker (e.g., No. 9) onto the tang and strike it briefly and firmly with a hammer. The tang will break cleanly at its predetermined breaking point.

5. Finished Thread:

   • Your new, high-strength, and durable thread is now ready for use!

This comprehensive kit includes all the necessary tools and inserts to immediately begin thread repair or reinforcement:

• 5x STI Single-Pass Taps, Form D, HSS-G:

  • UNF 1/4 x 28 (VÖLKEL 03155)

  • UNF 5/16 x 24 (VÖLKEL 03156)

  • UNF 3/8 x 24 (VÖLKEL 03157)

  • UNF 7/16 x 20 (VÖLKEL 03158)

  • UNF 1/2 x 20 (VÖLKEL 03159)

• 5x Tang Breakers:

  • No. 9 (VÖLKEL 07009)

  • No. 11 (VÖLKEL 07011)

  • No. 13 (VÖLKEL 07013)

  • No. 14 (VÖLKEL 07014)

  • No. 15 (VÖLKEL 07015)

• 5x Manual Installation Tools with Locking Ring:

  • No. 9 (VÖLKEL 08009)

  • No. 11 (VÖLKEL 08011)

  • No. 13 (VÖLKEL 08013)

  • No. 14 (VÖLKEL 08014)

  • No. 15 (VÖLKEL 08015)

• Thread Inserts - Type S - free running (Length: 1.5 D):

  • 25x UNF 1/4 x 28

  • 25x UNF 5/16 x 24

  • 25x UNF 3/8 x 24

  • 10x UNF 7/16 x 20

  • 10x UNF 1/2 x 20

• STI Spiral Drills:

  • 6.7 mm

  • 8.3 mm

  • 9.8 mm

  • 11.5 mm

  • 13.0 mm