Understanding E-File Directions: Do You Really Need Left-Handed Bits?

Most electric nail files (E-files) come with two rotation settings: forward and reverse. These settings aren’t just random – they relate to the direction your bit spins and how it interacts with the nail depending on your working angle.

• Forward direction: Spins the bit in a way that works best for right-handed techs working from right to left.

• Reverse direction: Spins the bit in the opposite way, ideal for left-handed techs working from left to right.

If you use the wrong rotation for your working direction, you’ll notice resistance, a lack of smooth control, and your bit may even skip or jump. Not ideal for precision work.

But here’s the catch…

Not all techs work in one consistent direction, regardless of being right or left-handed. Technique, comfort, and the area you’re working on can all influence which rotation works best. For example, many nail techs prefer working from side to centre when doing cuticle work, switching directions to match the curve of the nail. That’s why it’s so important to choose an E-file that offers both forward and reverse settings — it gives you the flexibility to work your way.

Also, when working on your non-dominant hand, reversing the direction can make control and precision much easier.

So… do you really need left-handed bits?

In most cases, no.

Most E-file bits including all Katie Barnes e-file bits are designed to be universal, meaning the teeth or flutes are cut to face straight out from the centre, allowing them to be used effectively in both directions. This is different from how bits fit into machines - it’s purely about the cutting direction.

Some bits are marketed as “directional,” meaning their teeth are cut to be more aggressive in one rotation only. However, the difference is usually minimal and can actually be limiting. With directional bits, you’d have to constantly switch bits when changing direction, which can disrupt your workflow.

This is mostly relevant to carbide bits. Diamond bits (commonly used for cuticle work) are almost always universal, making them suitable for both directions straight out of the box.

As a left-handed tech myself, I find no added benefit to using left-handed cut bits. I personally prefer high-quality universal bits, as they give me the freedom to switch directions based on the technique — not the label.

Choose an E-file with forward and reverse options, and invest in quality universal bits. This combo gives you the flexibility to work comfortably, safely, and efficiently - no matter which hand you’re using or what technique you’re performing.