E-Z Coil™ Thread Repair Kits

Don't start your next project without the E-Z Coil™ Thread Repair Kit from E-Z LOK. Our large selection of helical wire coil thread repair kits include all the essential items you need to install and repair tapped holes in softer metal materials like cast iron, mild steel, and aluminum.


Depending on your specific needs, we offer both standard and budget-friendly equipment in an assortment of sizes. Each E-Z Coil™ Thread Repair Kit includes a set of inserts, an STI tap, and an installation tool; the standard edition also includes a tang break tool and drill bit.


Each helical wire coil kit is offered in three separate styles:

  • For spark plugs
  • In metric sizes
  • In inch sizes

In addition to what we offer below, E-Z LOK™ has kits for other applications, such as the E-Z Knife™ Threaded Insert Kits for hard wood and E-Z Hex™ Drive Threaded Insert Kits for soft wood.


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How does an E-Z coil threaded insert repair kit work?

Our E-Z Coil™ threaded insert repair kit is designed to be user-friendly and make completing your project as simple as possible. First, drill out the damaged thread with the appropriate drill. Then, tap the hole with the included STI tap. It is very important you are using an STI tap. They are designed specifically for coil wire threaded inserts for metal materials like aluminum, cast iron, and mild steel. Once the hole is tapped, use the included installation tool to wind the insert into place. Apply light downward pressure until the top of the coil is 1/4 to 1/2 turn below the surface. To break off the installation tang, place either the included tang break tool or the installation tool on the tang and then tap down sharply with a hammer.

1. When should I use a helical wire coil thread repair kit?

Our helical wire coil thread repair kits are best suited for projects involving the following soft metals:

  • Cast iron
  • Mild steel
  • Aluminum

They're specifically designed to install and repair tapped holes and help you work efficiently.

2. What's the difference between economy and standard helical wire coil thread repair kits?

Apart from economy kits costing less, there is a slight difference in what the kits offer. Both kits include threaded inserts, STI taps, and installation tools, but the standard kits also include a drill bit and tang break tool.

3. Are helical wire coil threads stronger than other threads?

Helical wire coil inserts are typically the strongest thread when they are of the correct length and fitted properly for a project.

How to Install Coil Inserts from E-Z LOK

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