Do all drill bits fit into my new Saeyang nail drill?

Buying a Saeyang Marathon is a milestone for any nail tech. It’s the "Ferrari" of nail drills, reliable, sleek, and powerful. But once that beautiful box arrives, the panic often sets in: “Can I still use my favorite bits, or did I just buy an expensive paperweight?”

In this deep dive, we’ll dispel the myths, save your handpiece from expensive repairs, and show you exactly what to look for.

1. The Universal Standard (The Good News)

Let’s start with the weight off your shoulders: Yes, your bits will almost certainly fit. The professional nail industry operates on a universal shank size. Whether you have a Saeyang Marathon 3 Champion, a Mighty, a K38 PRO, or a K35 MINI, they all use the same collet size.

• The Magic Number: 2.35 mm (or 3/32 inch).
• Compatibility: This is the standard for 99% of professional bits (Carbide, Diamond, Ceramic, and Sanding Band Mandrels)

2. Quality Over Compatibility: Don’t Kill Your Motor

This is where most nail techs go wrong. Just because a bit fits doesn't mean it’s healthy for your machine. A Saeyang is a high-precision instrument; feeding it low-quality bits is like putting cheap oil in a supercar.

The Danger of "Off-Balance" Bits

Cheap bits (often found in bulk on discount sites) are frequently "off-center." Even if you can’t see it with the naked eye, at 30,000 RPM, that tiny imbalance causes micro-vibrations.

• The Result: Those vibrations travel straight into the ball bearings of your handpiece.
• The Cost: Replacing bearings can cost a significant portion of a new handpiece. If your handpiece starts getting "loud" or "hot," your bits are likely the culprit.

Check the Material

• Tungsten Carbide: Best for removing gel or acrylic without heat buildup.
• Diamond Bits: Perfect for precise cuticle work.
  • Safety Tip: High-quality bits are milled from a single piece of metal. If a bit looks like it's "glued" together, stay away!

3. Pro-Tips for Longevity (Protect Your Investment)

Your Saeyang can last 10+ years if you follow these four golden rules:

A. The "Never Empty" Rule

Crucial: Never close the twist-lock chuck without a bit or the "blank" shipping pin inside. Why? The internal spring is under high tension. Closing it empty can cause the mechanism to seize or weaken over time.

B. The Clean Entry

Before you slide a bit into your handpiece, give the shank a quick wipe with a lint-free wipe. A single grain of acrylic dust inside the collet can cause the bit to get "stuck" or lead to internal friction.

C. Watch the Speed vs. Size

Not all bits are meant for 35,000 RPM.

• Large bits (like large umbrella carbides) should be used at lower speeds.
• Small bits (like tiny flames) can handle higher speeds.
• Using a large, heavy bit at max speed can bend the internal spindle of your Saeyang.

Final Thoughts

Your Saeyang is designed to be your best friend in the salon. By choosing high-quality, 2.35mm bits and keeping your handpiece clean, you’ll enjoy smooth, whisper-quiet rotations for years to come.

Got a specific bit and not sure if it’s safe? Drop a photo in the comments or send us a message—we’re happy to help!