Coating Removal · E-File Technique
E-File Bit Shape for Gel Coating Removal: Why Straight Outperforms Tapered Every Time
A note on technique: The bit selection guidelines in this article reflect VEL Academy's recommended approach for maximizing speed and consistency in Russian manicure. Other schools and practitioners may use different bit shapes or sequences for coating removal. What is described here is the methodology VEL Academy has developed and teaches for efficient, repeatable results — not a universal rule of nail practice.
The bit you choose for gel coating removal is not a preference — it is a technical decision that directly affects how fast you work, how much heat you generate, and whether the nail plate is intact at the end of the removal stage. Most nail techs learn bit shape by habit rather than by reasoning. This article explains the reasoning.
Why Bit Shape Matters More Than Grit
When most nail technicians think about choosing a removal bit, they focus on grit — coarse vs fine, blue vs purple. Grit matters, but it is secondary to shape. The shape of the bit determines how contact is distributed across the nail surface during each stroke, and that distribution is what controls heat, pressure, and removal evenness.
There are two primary shapes used in e-file nail work: straight (corn-shaped) bits and tapered (cone-shaped) bits. They look similar in packaging, they fit the same handpiece, and they are often used interchangeably by nail techs who were never taught the difference. That interchangeability is the source of most of the heat complaints, nail thinning problems, and uneven removal results that are commonly attributed to speed or pressure.
Pro Burs №411 — straight carbide bit, purple grit
Kristall 31235 — straight carbide bit, blue grit
Kristall 13236 — left hand bit, blue grit
The Straight Bit: How It Works and Why It's Correct for Removal
A straight carbide bit — sometimes called a corn bit because of its cylindrical shape — has a consistent diameter from the base of the working surface to the tip. When you press this bit against the nail plate and move it across the surface, the contact area is uniform. The abrasive surface meets the coating at the same angle and with the same pressure distribution throughout the entire stroke.
This uniformity has two important consequences. First, it means the bit removes coating in an even layer rather than creating grooves or uneven thinning. Second, it means heat is distributed across the full contact surface rather than concentrated at a point. The result is faster removal with significantly less risk of thermal injury to the nail plate.
In Russian manicure technique, the straight bit is always the correct choice for the removal stage. Whether you use Pro Burs №411 in purple grit, Kristall 31235 in blue, or Kristall 13236 for left-hand strokes, the shape principle is the same: straight, with consistent diameter across the working surface.
The Tapered Bit: What It Is Actually Designed For
Tapered (cone) bit — correct for internal filing, incorrect for coating removal
A tapered bit narrows from the base toward the tip. This shape is not a design flaw — it is intentional, because tapered bits are designed for a specific purpose: internal filing. Internal filing means working inside the arch of the nail near the growth zone, where the narrow tip allows precise access to a confined space without touching the surrounding skin.
When a tapered bit is used for coating removal, the narrowing creates a problem. As the bit moves across the nail surface, the diameter of the contact area changes depending on where the working surface meets the coating. At the base, the bit has its widest diameter and works correctly. At the tip, the diameter is narrowest and the bit concentrates its full rotational force into a small point of contact. That concentration generates localized heat and digs unevenly into the coating — and into the nail plate underneath it.
The rule is simple: straight bits for removal and surface work. Tapered bits for internal filing only. Using the wrong bit in the wrong stage does not just slow you down — it creates conditions for nail plate damage that accumulate over multiple appointments.
Grit Selection: Blue, Green, and Purple
Once you have established that your removal bit must be straight, grit selection becomes relevant. Carbide removal bits are available in three standard grit colors, each indicating a different level of abrasiveness:
- Purple grit — the coarsest option, removes material the fastest. Best for thick gel or polygel coatings where significant material needs to be cleared quickly.
- Blue grit — medium coarseness, the most versatile option. Works across most coating types and is forgiving enough for less experienced hands.
- Green grit — the finest of the three, best used for clients with thinner coatings or more sensitive nail plates where you want more controlled removal.
The Pro Burs №411 in purple band and the Kristall 31235 in blue grit are the primary bits used in VEL Academy courses. Both are straight, both are carbide, and they cover the most common removal scenarios between them.
Left-Hand vs Right-Hand Bits: What the Designation Means
Some carbide bits, like the Kristall 13236, are designated for left-hand use. This designation refers to the direction of the cutting edges — not the hand of the technician.
Standard removal bits are optimized for FWD (forward) rotation of the handpiece. Left-hand bits are optimized for REW (reverse) rotation. Using a standard bit in REW rotation, or a left-hand bit in FWD, reduces the cutting efficiency and can create a burnishing effect rather than actual removal.
For most removal strokes in a standard Russian manicure sequence, a standard straight bit in FWD at 35,000 RPM is correct. Left-hand bits become relevant for specific stroke directions where REW rotation provides better control — particularly on the right side of the nail when working right-handed.
