Threading in Aluminum – How to Create Strong Screw Connections in Light Metal

Not only in the automotive industry has lightweight construction played an increasingly important role for many years, many other industries also rely on this design method to save material and money. The principle is simple: The lower the weight, the easier components can be moved. In all types of land and air vehicles, this can have a significant impact on fuel consumption.

However, not every material is suitable for lightweight construction. Particularly popular are light metals such as aluminum and aluminum alloys. They offer low weight and are easy to machine, but can cause problems elsewhere. You surely know this if you have ever tried to cut a thread in aluminum.

But don’t worry, aluminum threads can be tricky at times, but with the right know-how and a bit of finesse, they can be handled well even by DIY enthusiasts and hobbyists. If you want to know how it works, just keep reading. We will tell you all the tips and tricks about aluminum that you should know.

What makes aluminum such a special material?

Aluminum is soft and tough, it can be stretched and rolled and is therefore easy to form. Its low density makes it ideal for use in aerospace, where a lot of mass needs to be moved, but it is also used in countless other areas. From electrical engineering, where it is used as a conductor material, to mirror coatings in scanners or SLR cameras, to the packaging industry and as a household aid in the kitchen where aluminum foil keeps leftovers fresh.

The flexibility is related to the good formability of aluminum, and that also has its downsides. Although the soft material can be machined well with a tap, sometimes it can be a bit too easy. The thread can quickly become rough or have too much play.

The chip formation of aluminum can also be problematic. Aluminum chips are often long and bulky depending on the alloy. They need enough space, otherwise they can clog the drilled hole, get stuck, and damage the thread.

To use the advantages of the material without having to accept the disadvantages, you should follow a few tips.

Cutting threads in aluminum – With these tips it will work for you too

Cutting external and internal threads in aluminum to create a stable screw connection can be challenging. But if you proceed step by step and follow some advice, you can achieve very good results even in this demanding material.

Use a suitable tap for aluminum

The most important thing first: Not every tap is suitable for aluminum. Both the geometry and the coating must match the cutting application so that the chips have space, are well removed, and the tool can glide smoothly through the material. There are special taps designed only for thread cutting in aluminum that you should definitely use.

Avoid overheating

To cut a clean thread in aluminum, you should ensure that the material does not heat up too much while working. Use a suitable cutting oil and apply it generously to the tool and workpiece before cutting. A low rotational speed, as used with thread-cutting machines or when working by hand, also helps to prevent overheating.

Pay attention to care and cleanliness

When cutting threads, always ensure that your taps and dies are clean and that the cutting edges are sharp. Aluminum tends to oxidize and adhere to tools, so you should regularly check your taps for wear and contamination.

Reinforcing internal threads in aluminum with thread inserts

If despite our tips your aluminum thread does not turn out well or becomes damaged and your screws no longer hold securely, all is not lost. With thread inserts, you can repair threads in aluminum without changing the diameter or thread pitch.

Especially with a high value material such as aluminum, it can be very annoying to replace an entire component because of a damaged thread, whether in industry or DIY. Thread inserts are a cost-effective and simple solution to this issue.

By the way, you can also use inserts from the outset to reinforce threads in aluminum. Especially when every gram counts, fewer or smaller screws can be a real cost factor. Thread inserts make this possible and additionally increase the pull-out strength.

Taps for aluminum and more in the BAER online shop

In the BAER online shop, you will find threading tools specifically designed for use in aluminum to help you optimize the quality and service life of your internal and external threads. You can find an overview most easily by using the Toolfinder on our website. Simply select “Aluminum” under application and all matching products will be displayed.

With our two product ranges BaerCoil and BaerFix, we also offer thread inserts with which you can repair or reinforce your aluminum threads. The inserts are available for many thread types and provide stable connections in aluminum and many other metals.

Do you have a question or need more information? Our customer service team is happy to help. Simply contact us by phone or via our contact form.