---
product_id: 6253906
title: "5521-4 1/4-20 Inch Coarse Thread Repair Kit"
brand: "helicoil"
price: "€ 45.98"
currency: EUR
in_stock: true
reviews_count: 8
category: "Helicoil"
url: https://www.desertcart.it/products/6253906-5521-4-1-4-20-inch-coarse-thread-repair-kit
store_origin: IT
region: Italy
---

# 1/4-20 coarse thread size, .375 length Complete kit with tap & installation tool 12 precision stainless steel inserts 5521-4 1/4-20 Inch Coarse Thread Repair Kit

**Brand:** helicoil
**Price:** € 45.98
**Availability:** ✅ In Stock

## Summary

> 🛠️ Fix it like a pro—never let stripped threads slow you down!

## Quick Answers

- **What is this?** 5521-4 1/4-20 Inch Coarse Thread Repair Kit by helicoil
- **How much does it cost?** € 45.98 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.it](https://www.desertcart.it/products/6253906-5521-4-1-4-20-inch-coarse-thread-repair-kit)

## Best For

- helicoil enthusiasts

## Why This Product

- Trusted helicoil brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Compact & Portable:** Lightweight 0.8 oz kit with smooth exterior and carded packing, perfect for on-the-go fixes or workshop essentials.
- • **All-in-One Convenience:** Includes detailed instructions, Heli-Coil tap, and installation tool—everything you need in one sleek kit.
- • **Durability Meets Simplicity:** Crafted from premium materials to resist wear, corrosion, and over-torque damage—repair with confidence.
- • **Precision Engineered Repair:** Restore stripped threads with 12 high-grade stainless steel inserts for lasting durability.
- • **Universal Fit for Inch Threads:** Specifically designed for 1/4-20 coarse threads, ensuring perfect compatibility and professional results.

## Overview

The Helicoil 5521-4 Inch Coarse Thread Repair Kit is a professional-grade solution designed to restore stripped or damaged 1/4-20 tapped holes. Featuring 12 precision stainless steel inserts, a dedicated Heli-Coil tap, and installation tool, this compact kit delivers durable, corrosion-resistant repairs with ease. Ideal for mechanics and DIY enthusiasts seeking reliable thread restoration in a portable, all-inclusive package.

## Description

Helicoil Inch Coarse Thread Repair Kit includes inserts, detailed instructions, Heli-Coil tap and installation tool. It is made from high quality material and is extremely long lasting. This inch coarse thread repair kit is used for repairing tapped holes which have been stripped or damaged, due to wear, corrosion and over torque. It comes with a package type of durable placon or vinyl pouches. Thread Size 1/4-20 x .375 Length. Heli-Coil inserts are precision formed coils of extremely hard stainless steel.

Review: Worked for Harley derby cover. - Worked great to replace the stripped threads on my Harley primary for the derby cover. Recommend buying an actual tap handle to go with it. Tap cut the threads cleanly and the helicoils went in well. Set comes with enough coils to replace all the threads for the derby cover. May as well drill them all out and replace them.
Review: Awsome tool - Great tool, works like a charm. One thing you should know is that the kit does not come with the tap handle. The image above does not match what you get. This is more like what you get Helicoil 5546-6 M6 x 1...

## Features

- The product is 1/4-20thread repair kit
- Easy and simple use kit
- The product is manufactured in china
- Includes 12 inserts, complete instructions, Heli-Coil tap and installation tool
- Used for repairing tapped holes
- Made from high quality material
- Comes in carded packing
- Easy to use

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Manufacturer | Heli-Coil |
| Brand | Helicoil |
| Model | 5521-4 |
| Item Weight | 0.8 ounces |
| Product Dimensions | 3.7 x 0.4 x 4.5 inches |
| Item model number | 5521-4 |
| Is Discontinued By Manufacturer | No |
| Exterior | Smooth |
| Manufacturer Part Number | 5521-4 |

## Images

![5521-4 1/4-20 Inch Coarse Thread Repair Kit - Image 1](https://m.media-amazon.com/images/I/71CGPWx5PnL.jpg)

## Questions & Answers

**Q: what size is the tap in this kit???**
A: The tap is special for Heli-Coil and not a standard bolt size.  The ID of the coil is 1/4-20 but the tap cuts the thread for the coil OD so it is still 20 tpi but much larger than 1/4 inch.  The only larger tap with 20 tpi is 7/16 which is far too large.

**Q: How do I break off the tang?**
A: Use the installation tool with the slot. Leave in place when you install helicoil and tap tool with hammer, this will break tang.

**Q: Can this tap a new hole?**
A: I used it to repair threads.  If the new hole is close to 17/64 it will work.  The recommended drill is 17/64, if the new hole is larger than 17/64 you will not get the proper thread cut, if the new hole is smaller than 17/64, drill the new hole to 17/64.

**Q: Can these heli-coils be used in a set screw application?**
A: Yes! As long as there is enough depth to the hole and use the correct coil and screw length.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Worked for Harley derby cover.
*by M***E on August 16, 2025*

Worked great to replace the stripped threads on my Harley primary for the derby cover. Recommend buying an actual tap handle to go with it. Tap cut the threads cleanly and the helicoils went in well. Set comes with enough coils to replace all the threads for the derby cover. May as well drill them all out and replace them.

### ⭐⭐⭐⭐⭐ Awsome tool
*by E***I on November 19, 2012*

Great tool, works like a charm. One thing you should know is that the kit does not come with the tap handle. The image above does not match what you get. This is more like what you get Helicoil 5546-6 M6 x 1...

### ⭐⭐⭐⭐⭐ Easy! Works!
*by F***R on October 3, 2012*

Five starts for ease and result I had stripped threads for a bracket inside the stern of a small boat, hard to tell what it was until doing some "surgery." I determined that it was about 3/8" thick, probably steel, and worth tapping, so I bit the bullet. Tried JB weld first to make threads: *bzzzt* FAIL Next stop, Helicoil. SO easy, it seemed to good to be true. Drill out, quick. Tapping was a bit dicey; I have NEVER tapped threads before, and it was hard to turn at first, then real easy, like it had stripped (it had not). Still, easy. Helicoil screwed right in; being inside it was a little hard to see when to stop turning it in, but no big deal. With such a thin bracket there was a narrow "sweet spot." Bolt went right in, not to loose, not too snug. Done. Pros quick and easy enough inserts for many more fixes saved me LOTS of time and money Cons enough inserts for many more fixes = $$ (cheaper kit with fewer inserts would be nice) need your own 17/64 drill, which is in most bigger drill sets

## Frequently Bought Together

- Helicoil 5521-4 1/4-20 Inch Coarse Thread Repair Kit
- Helicoil 5521-5 5/16-18 Inch Coarse Thread Repair Kit
- Heli-Coil 5521-6 3/8-16 Inch Coarse Thread Repair Kit

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*Product available on Desertcart Italy*
*Store origin: IT*
*Last updated: 2026-03-17*