Thread Repair Kits, UNC 5/8 - 1,5D

• for repairing damaged or worn UNC 5/8 x 11 internal threads
• for components where the original internal thread no longer provides reliable holding force
• for thread reinforcement in materials with lower shear strength, such as aluminium and magnesium alloys
• for creating a durable internal thread with a free-running Type S wire thread insert
• for maintenance workshops, assembly work, service departments, machine building and metalworking
• Process: manual or assisted drive depending on your tool holder and machine configuration
• Use: thread cutting, thread recutting and thread cleaning depending on the condition of the thread

Note Before starting the repair, check the thread designation, component condition, wall thickness and available installation depth. Stable alignment is essential so the insert seats correctly in the STI thread.

• complete kit configuration for UNC 5/8 x 11 internal thread repair
• STI tap and inserting tool are matched to the wire thread insert repair process
• 10 included wire thread inserts allow several repairs in the same thread size
• Type S is free running and restores a normal internal thread without a locking effect.
• stainless steel wire thread inserts support a strong and corrosion-resistant internal thread
• useful for service jobs where component replacement should be avoided
• the metal case protects the individual parts and simplifies workshop organisation

• The repair is only reliable when drilling, STI tapping and insert depth are carried out cleanly; follow the kit sequence carefully from preparation to final inspection.
• A twist drill for drilling out is not included; the diameter is given in the technical information on V-COIL tapping drill sizes.

1. Inspect the damaged internal thread and confirm that the component structure is suitable for a wire thread insert repair.
2. Securely align the component and make sure the tool axis follows the existing thread axis.
3. Drill out the damaged thread area with a twist drill according to the V-COIL tapping drill size table.
4. Cut the STI receiving thread with the STI short machine tap and a suitable cutting lubricant.
5. Clean the receiving thread thoroughly and remove all chips from the repair area.
6. Place the wire thread insert into the inserting tool and guide it straight to the receiving thread.
7. Install the insert in a controlled movement in the thread direction until the intended installation position is reached; never turn it against the running direction.
8. Remove the driving tang with pointed pliers, as is usual for large sizes.
9. Check the repaired thread with a matching screw or suitable inspection method.

Taps, dies and cutting tools

• 1 piece STI Short Machine Tap ISO 529 Form D HSS-G - UNC 5/8 x 11 (03113)

Thread inserts and repair components

• 1 piece V-COIL Inserting Tool No. 18 (08018)
• 10 pieces V-COIL Wire thread insert Free running type S UNC 5/8 x 11 - 1.5 D (50 pcs.) (08314)

Storage and identification

• 1 piece metal case (99VC003)
• 1 piece plastic insert (99VC005)

• Product class: thread repair
• Product type: V-COIL thread repair kit
• Thread system: UNC coarse thread (UNC)
• Nominal size: UNC 5/8 x 11
• Insert length: 1.5D
• Insert type: Type S, free running
• Insert standard reference: DIN 8140
• Insert tolerance: ISO 2 (6H)
• Insert material: stainless steel
• Tap: STI Short Machine Tap ISO 529 Form D HSS-G - UNC 5/8 x 11
• Inserting tool: V-COIL Inserting Tool No. 18
• Storage: metal case

What is this thread repair kit used for?
It is used to repair damaged, worn or stripped UNC internal threads UNC 5/8 x 11. The wire thread insert restores a functional internal thread inside the prepared STI receiving thread.

Why is the thread designation so important?
It is the key selection criterion. It must match the component, the screw and the repair requirement so that the drill, STI tap and insert work together correctly.

Why can’t a standard tap be used for the insert?
A standard tap produces a normal screw thread. The insert requires a special STI receiving thread, which is created with the STI tap included in this kit.

Where can I find technical information on V-COIL thread repair?
The repair principle with STI thread and wire thread insert is explained here: Technical information V-COIL thread repair as PDF.

Which insert type does the kit contain?
Type S is free running and restores a normal internal thread without a locking effect.

Where can I find information on wire thread inserts according to DIN 8140?
Further technical details are available here: Technical information wire thread inserts DIN 8140 as PDF.

Which drill do you need for drilling out?
The matching hole diameter for the STI receiving thread is given in the Technical information tapping drill sizes V-COIL as PDF.

Where can I find the V-COIL system catalogue?
The catalogue for V-COIL thread repair systems and accessories is available here: VC 23 catalog as PDF.