Buying task · E-files
E-files: how to choose a nail drill
How to choose an e-file: corded or cordless, the 3/32-inch bit fit, what RPM and torque figures show, controls, voltage, warranty and the skill it takes.
Short answer
For a desk, choose a corded e-file whose maker states a 3/32-inch bit shank, an input that covers 120 V and a warranty you can use; choose a cordless one only if you work away from an outlet. Treat RPM and torque as the maker's figures, not measurements, and get trained before you file natural nails: NailKnowledge says it is very quick and easy to seriously damage the nail plate with an e-file.[1]
What an e-file is
An e-file (a nail drill) has two main parts: a controller, the box or dial that sets speed and direction, and a handpiece that holds the bit in a chuck. Some kits add a foot pedal: Medicool's corded Pro Power 35K, for example, comes with an on/off pedal.[2]
Pro kits are often a system. KUPA lists six handpieces as compatible with its Passport NEXT control box, from the KP-36 to its Companion handpiece, so a handpiece can be replaced or changed without buying a new controller.[3] The what is an e-file guide explains each part.
The decisions, in order
1. Corded or cordless. A corded e-file runs from the wall through its controller; a cordless one carries a battery in a portable control box. Cordless kits trade battery runtime claims for freedom to move: KUPA, for example, claims 10-12 hours for its Passport NEXT.[3] The corded vs cordless guide and the portable kits overview cover that trade.
2. Bit fit. The shank size decides which bits you can use. KUPA's KP-55 and Passport NEXT and Medicool's 35K Portable all list standard 3/32-inch bits.[4][3][5] Not every page says: Kiara Sky's Beyond Pro Portable page and Young Nails' EF300P page do not state a shank size.[6][7] If the shank is not stated, ask before you buy. The bits and fit overview explains why.
3. Speed claims. Makers list top speeds of 30,000-35,000 RPM for pro handpieces: KUPA's KP-55 at 30,000, Medicool's corded 35K up to 35,000, Young Nails' EF300P with variable speed from 0 to 35,000.[4][2][7] These are maker figures, not speeds measured under load. Medicool positions its 20K model, at up to 20,000 RPM, for beginners and personal use.[8]
4. Torque. Few makers publish torque. Medicool lists 4.8 N-cm for the 35K Portable without a test method, so do not compare it with another brand's number as if both were measured the same way.[5] The RPM and torque guide explains what the numbers can and cannot tell you.
5. Controls. Look for forward/reverse and variable speed. KUPA lists both for the Passport NEXT, plus a pause button and a digital RPM display.[3] Reverse matters most to left-handed techs; see forward and reverse on a nail drill.
6. Voltage, adapter and warranty. Medicool's corded 35K runs from an included 110-220 V controller and carries a one-year warranty.[2] Medicool tells owners to use only Medicool-approved power adapters, and its warranty excludes damage from incorrect voltage or adapters and products bought from unauthorized resellers.[8] Kiara Sky lists a one-year manufacturer's warranty for its portable drill and sells it for professional use only.[6] The voltage and plugs guide covers the adapter question.
Speed, heat and the nail plate
Medicool's FAQ suggests about 5,000-10,000 RPM for natural nail prep and cuticle work, 15,000-20,000 RPM for gel removal and 20,000-25,000 RPM for acrylic removal, starting low and increasing gradually.[8] That is one maker's suggestion, not a rule, and Medicool's own 2025 guide gives different ranges.[9]
Medicool also advises not running a drill continuously at maximum speed for long periods and replacing worn bits, because dull bits cause extra heat and pressure.[8] NailKnowledge attributes rings of fire on the nail plate mainly to over-filing, with bit angle, bit quality, speed control and the number of passes as factors.[10]
How to choose
- Pick the power source from where you work: corded for a fixed desk, cordless for mobile work.
- Confirm the shank size on the maker's page. Prefer a handpiece whose maker states 3/32 inch.
- Confirm the input covers 120 V, and that the adapter in the box is the maker's own.
- Check the warranty and who sells it. Medicool's warranty excludes unauthorized resellers, so buy through a channel the brand names.[8]
- Choose speed for your training, not the biggest number.
We have not shortlisted a specific e-file yet: none of the listings we reviewed so far showed both a seller the brand links to and a stated 120 V US plug. The equipment type finder shows what each kind of equipment does.
Every page on e-files
Guides
- What is an e-file? Controller, handpiece and chuck explained
- Nail drill RPM and torque: what 30K and 35K do and don't tell you
- Forward and reverse on a nail drill, and bits for left-handed techs
- Why a nail drill handpiece gets hot
- Nail drill care: wiping down, replacing bits and getting repairs
- Rings of fire: what nail educators say causes them
Equipment types
Related topics
Everything in this topic
Guides
- Nail drill care and repairsHelps you keep a drill working, know when a bit is worn out, and avoid voiding the warranty before a repair.
- Forward and reverse on a nail drillHelps left-handed techs, and anyone working both sides of the nail, choose a drill and bits that cut in the direction they need.
- Nail drill RPM and torqueStops you paying for a bigger RPM number you will rarely use, and shows what to compare instead.
- Rings of fire on the nailHelps you spot the technique habits behind rings of fire before they damage a client's or your own nails.
- What is an e-file?Helps you understand the parts of an e-file before you compare models, so you know which specs belong to which part.
- Why a nail drill handpiece gets hotHelps you tell normal warmth from a handpiece that needs service, and fix the causes you control.
Common questions
How often should I replace nail drill bits?
When they stop cutting cleanly. For daily professional use, Medicool estimates about 2-4 months for carbide, 3-6 months for ceramic and 6-12 months for diamond, but that is one maker's estimate. More in Nail drill care and repairs
How do I clean a nail drill handpiece?
Wipe it down. Medicool says motorized handpieces should never be submerged in liquid. Wiping is care for the drill, not a hygiene guarantee. More in Nail drill care and repairs
Where can I get a nail drill repaired?
Through the maker. KUPA, for example, runs an authorized repair-center locator on its site and asks owners without a nearby center to contact KUPA. More in Nail drill care and repairs
What voids a nail drill warranty?
It depends on the maker. Medicool's warranty excludes damage from incorrect voltage or power adapters and products bought from unauthorized resellers. More in Nail drill care and repairs
Do left-handed nail techs need a special drill?
They need a drill with a reverse setting and bits that cut in reverse. Many e-files have forward/reverse, including KUPA's Passport NEXT and Medicool's Pro Power 35K Portable. More in Forward and reverse on a nail drill
What is a two-way nail drill bit?
A carbide bit made to cut in both directions. Medicool designed its 5-in-1 carbide bit (CC22) to cut clockwise and counter-clockwise and markets it for right- and left-handed techs. More in Forward and reverse on a nail drill
Are left-hand bits available for every shape?
No. Erica's ATA sells many of its bits in left- and right-hand versions, but not every bit comes in both, so check each one. More in Forward and reverse on a nail drill
Do all MelodySusie drills have reverse?
MelodySusie's FAQ says its drills have forward/reverse and a speed knob, but that is a general answer for the range. Confirm it on the listing or manual for the exact model. More in Forward and reverse on a nail drill
Questions
Is a 35,000 RPM nail drill better than a 30,000 RPM one?
Not by that number alone. RPM is the maker's stated top speed, not a measurement under load, and Medicool's own FAQ suggests working well below it: about 5,000-10,000 RPM for natural nail prep and 15,000-20,000 RPM for gel removal, starting low.[8]
Which e-file speed suits a beginner?
Medicool positions its Pro Power 20K, which runs up to 20,000 RPM, for beginners and personal use, and its 30K and 35K models for professionals. Whatever the top speed, start low and build up with training.[8]
Can I compare torque figures between brands?
Not reliably. Medicool lists 4.8 N-cm for its 35K Portable but does not state how it measured that figure, so a number from another brand may not be measured the same way.[5]
Is an e-file safe for home use?
NailKnowledge, a nail-education site, says e-files are safe in trained hands but that it is very quick and easy to seriously damage the nail plate with one. Get training before you use one on natural nails.[1]
Can I use any power adapter with my e-file?
Use the one the maker supplies or approves. Medicool tells owners to use only Medicool-approved power adapters, and its warranty excludes damage from incorrect voltage or power adapters.[8]