Today, we will introduce you to the Wire insert which was originally designed to repair parts with damaged threads, but has evolved for use in a variety of applications that save time and money and improve product reliability. Do we have your attention? Great, then read on…
|What is a Wire Insert?
Wire inserts are precision-formed continuous wire coils that provide permanent, wear-resistant threads which exceed the strength of the parent material. Often underestimated, the popular misconception is that Wire inserts are intended solely for thread repair, when, in fact, they have other significant uses discussed in the next section. Not to be confused with other types of solid inserts or rivnuts, Wire inserts resemble springs and are sometimes referred to as “helicals”.
Who uses Wire Inserts?
Wire inserts are used for 3 main reasons: 1) to repair damaged threads in parts that would otherwise have to be scrapped; 2) to strengthen threads against failures due to stripping, seizing or corrosion; 3) to convert threads between inch and metric sizes. We told you they were versatile!
|What styles are available?
Wire inserts come in 2 main styles: tang and tangless.
The original and widely used tang style has a prong at one end to facilitate installation. The newer tangless style is becoming popular since this style had no prongs to break off, retrieve, or lose and is easily adjusted or removed after installation. Tangless inserts are commonly used in electronic applications where loose tangs might cause damage.
Wire Inserts can be free-running or locking.
Free running is the most common style used for thread repair. The “free” diameter of the insert is larger than the installed diameter and this configuration generates balanced pressure distribution between the coils and threads.
Locking style inserts are recommended for applications that require constant torque, or are subject to stress or vibration. The locking style features a crimped turn that acts as a locking mechanism that grips the bolt or screw to prevent loosening from vibration, eliminating the need for lock wiring, lock-nuts, lockwashers, pellets/patches or other thread locking devices.
A third commonly used insert that deserves an honorable mention is a K-type Insert. Sometimes called by the brand Keensert, these externally threaded solid style inserts can be used in almost any material: aluminum, magnesium, cast iron, carbon steel, stainless steel and plastic. K-type inserts have locking “keys” that provide a mechanical lock, and are commonly used in heavy wear and high vibration situations.
|5 Features & Benefits of Wire Inserts
1. Repair rather than scrap parts – Wire inserts remain the most cost effective, efficient and fastest method to repair damaged threads.
2. Stronger Assemblies – The flexibility of the insert provides a more balanced load distribution, practically eliminating thread erosion and providing better stress allocation, even in low strength materials.
3. Wear and Corrosion Resistance – Thread life is increased as thread friction is virtually eliminated, which becomes valuable in applications requiring repeated assembly and disassembly. Surface coatings are available for applications involving severe corrosive and extreme temperature conditions.
4. Minimize space and weight – Lighter and less expensive than other thread inserts, these wiry fellows can be incorporated into existing designs, often allowing the use of thinner or lighter parent materials.
5. Convert threads from Metric/Inch – Rather than replace all your hardware, taps and dies, you can use Wire inserts to convert threads and use your existing hardware and tools.
|Lesson Learned, considerations when selecting and using Wire Inserts
|Wire Inserts Available at MF Supply
Here at MF Supply, we supply some of the most common and unusual Wire inserts, including:
For more detailed information on Wire inserts, visit us at http://www.mfsupply.com/SearchResults.asp?Cat=1821
And if you don’t see it listed, as always, ask us. Finding the right screw for you is our tag line after all!