This 5 piece refill pack contains V-COIL free running type S inserts for UNF 7/8 x 14 thread repair. The key selection points are thread designation, insert length 2.5 D, insert execution, and the repair system already used in the component.
UNF identifies a Unified fine inch thread used on inch based fasteners where a finer pitch is specified. Free running inserts are selected when normal screw running behavior is required after installation. Confirm the mating part, prepared hole, driving method, and cleanliness before you load the tool or insert. This makes the refill pack specific to production maintenance, workshop repair, field service, and plant engineering.
- rebuilding a worn or stripped internal UNF 7/8 x 14 thread after the hole has been prepared for the insert system
- using 2.5 D inserts when this length is specified for thread engagement or component wall thickness
- keeping spare inserts available for recurring repairs without replacing the complete kit
- controlled maintenance work where thread engagement must be checked after installation
Note Use only with the correct STI tap, installation tool, and thread preparation process for UNF 7/8 x 14.
- 5 piece refill pack supports recurring repairs where only inserts are consumed
- thread designation UNF 7/8 x 14 reduces the risk of mixing similar repair sizes
- V-COIL system structure keeps insert choice linked to the prepared STI thread and length 2.5 D
- repair concept can retain the original screw size when preparation and installation are controlled
Drawbacks
- This refill pack does not include preparation or installation tools; use a suitable V-COIL repair kit or tool set when the required tools are not already available.
- Compare UNF 7/8 x 14 and 2.5 D with the repair specification before opening the refill pack.
- Remove damaged thread material using the preparation tools specified for the repair system.
- Create the STI receiving thread with the matching repair tap.
- Clean the bore and thread flanks before the insert is installed.
- Install the wire insert to the specified seating position using the correct tool.
- Remove installation remnants where the process requires that action.
- Verify that the mating screw starts smoothly and reaches the required engagement.
- 5 pieces V-COIL free running type S inserts UNF 7/8 x 14 - 2.5 D
- System: V-COIL wire thread insert
- Insert execution: free running type S
- Thread system: Unified fine inch thread
- Thread designation: UNF 7/8 x 14
- Insert length: 2.5 D
- Pack quantity: 5 pieces
- When do you choose a refill pack instead of a complete repair kit?
- Choose a refill pack when the required drills, STI taps, inserting tools, and tang tools are already available for the repair system.
- Which thread does this insert match?
- This insert matches UNF 7/8 x 14. UNF identifies a Unified fine inch thread used on inch based fasteners where a finer pitch is specified.
- What does free running type S mean in assembly?
- Free running type S supports normal screw movement after correct installation and does not add a locking insert function.
- Why is insert length important?
- Insert length 2.5 D affects the available thread engagement in the repaired component and must match the repair requirement.
- Where can you find V-COIL thread repair technical information?
- Use the Technical information V-COIL thread repair as PDF.
- What should be checked after installation?
- Check that the insert sits below the entry surface where required, that the screw starts smoothly, and that no chips remain in the thread.
- How do you avoid mixing inch repair sizes?
- Compare thread family, nominal size, threads per inch, and insert length because similar inch sizes are not interchangeable.
- Where can you find the VÖLKEL thread repair catalog?
- Use the VC 23 catalog as PDF.
Do you need help selecting or using the product?
Use the contact form.
In this category: Thread repair
Related products: Wire Thread Inserts
