Nail Drill Bits Explained
Having the right bit makes as much difference as the drill itself. This guide covers the main bit types, materials, shapes, and grits — and which to use for each service.
All bits referenced here use the 2.35mm (3/32") shank — the universal standard that fits all Saeyang Marathon handpieces.
Bit Materials
Carbide Bits
The workhorse of professional nail tech. Carbide bits are precise, durable, and versatile — they cut cleanly and last a long time with proper maintenance.
Best for: Natural nail prep, cuticle work, product removal (gel, acrylic), shaping and refining.
Carbide bits come in different cut patterns: cross-cut (fine, smooth finish), straight cut (more aggressive removal), and spiral cut (efficient chip clearance). The pattern is usually marked on the shank.
Diamond Bits
Diamond bits use embedded abrasive particles rather than cutting edges. They're gentler than carbide and are used for more delicate work.
Best for: Cuticle care, natural nail surface work, nail art areas, callus softening at low RPM.
Ceramic Bits
Ceramic bits run cool — they generate less heat than metal bits during extended use. Useful for sensitive clients or long services.
Best for: Natural nail prep, gentle surface work on sensitive nails.
Sanding Bands / Mandrels
Abrasive bands fitted over a mandrel. The bands are disposable (single-use per client for hygiene), making them suitable for callus work and surface smoothing.
Best for: Pedicure work, callus softening, surface smoothing. Standard in podiatry settings.
Grit / Coarseness
Bits are graded from coarse to fine. Most bits are colour-coded by grit, though coding isn't universal across all manufacturers.
| Grit | Use |
|---|---|
| Extra coarse | Heavy product removal (rarely needed) |
| Coarse | Fast acrylic / gel bulk removal |
| Medium | General filing, gel removal, acrylic shaping |
| Fine | Surface refinement, finishing |
| Extra fine | Final smoothing, near-natural-nail work |
Rule of thumb: Start coarser than you think, finish finer than you think. Rushing finishing with medium grit shows in the final result.
Bit Shapes
Barrel / Cylinder
The most versatile shape. Used for acrylic and gel filing, surface smoothing, and general prep. Available in coarse through fine grits.
Cone / Tapered
Precise work in tight areas — sidewalls, lateral nail folds, under the free edge. Essential for clean cuticle lines on natural nail clients.
Ball / Round
Cuticle work, cleaning under the free edge, and getting into the sidewall groove. The round head is safer than a flat edge near the cuticle.
Flame
Detailed cuticle work and removing excess product from the sidewalls. The tapered point allows precise access.
Backfill Bit
Specifically designed for acrylic backfills — the angled flat head creates a clean smile line efficiently.
Mandrel + Sanding Band
Used with disposable sanding bands for pedicure callus work. The band wraps around the mandrel and is discarded after each client.
Which Bits for Which Service
| Service | Bit Type | Shape | Grit |
|---|---|---|---|
| Natural nail prep | Carbide | Cone or flame | Fine |
| Cuticle work | Diamond or carbide | Ball or cone | Fine |
| Gel polish removal | Carbide | Barrel | Medium |
| Hard gel filing | Carbide | Barrel | Medium-coarse |
| Acrylic removal | Carbide | Barrel | Coarse then medium |
| Acrylic shaping | Carbide | Barrel or backfill | Medium |
| Finishing | Carbide | Barrel | Fine-extra fine |
| Pedicure / callus | Sanding band on mandrel | Mandrel | Medium |
Cleaning and Maintenance
Carbide and diamond bits need regular cleaning to stay effective:
- During use: Brush loose debris with a metal brush between clients
- After use: Soak in acetone or isopropyl alcohol to dissolve product buildup
- Sterilisation: Autoclave where appropriate (check manufacturer guidance — not all bits are autoclave-safe)
- Inspect regularly: Carbide bits dull over time — a bit that's pulling rather than cutting cleanly needs replacing
Related Guides
Professional nail drills and equipment stocked by Coheal UK.
