What Nail File Grit Should I Use?
The nail file grit you need depends on the job in front of you. For gel and acrylic nails, start at 100 grit to remove bulk product, then move to 180 or 240 grit to refine and finish.
For natural nails, stay at 180 grit or higher to avoid thinning the nail plate, and most technicians quietly get that part wrong.
A file that's too coarse doesn't just feel rough, it strips away layers of keratin the nail plate needs to stay strong, one stroke at a time, until a client's natural nails stop holding product the way they used to, and neither of you can work out why.
Grit refers to the coarseness of a nail file's abrasive surface. The grit number tells you how many abrasive particles are packed into that surface: a lower grit number means fewer, larger particles and a coarser grit, a higher grit number means smaller, denser particles and a finer grit.
That's the whole trade secret. Three numbers, 100, 180 and 240, cover almost everything a professional nail file needs to do.
What Is a 100 Grit Nail File Used For?
A 100 grit file is the coarsest one you should be reaching for. It's built to remove enhancement, not to touch skin or natural nail. Use it to break down old gel, gel polish or acrylic during a rebalance, or to shorten an enhancement before you refine the shape.
The mistake nail technicians make with 100 grit is treating it like a shortcut. It removes material fast, which is exactly why it's dangerous on anything other than product.
One pass across bare natural nail with a 100 grit file can do more damage than a full set of extensions ever will, and it's the kind of damage a client usually blames on the gel, not the file, so you lose their trust without ever finding out why.
Once the bulk is gone, the file work isn't finished. It's just ready for something gentler.
When Should You Use a 180 Grit Nail File?
180 grit sits in the middle, and that's precisely what makes it the file most technicians reach for without thinking. It's soft enough to use with care on natural nails, and coarse enough to refine gel or acrylic once the bulk has already come off with a 100 grit file.
Think of 180 grit as the workhorse. It shapes the free edge, blends product into the natural nail, and carries you through most of a full set without a client ever noticing you've switched files.
If you only kept one grit file in your kit, this is the one that keeps a service moving instead of stalling halfway through.
180 grit will take you a long way. But there's still a job it isn't built for. That job belongs to 240 grit.
Is 240 Grit Better for Natural Nails?
Reach for 240 grit when the job is the natural nail itself, not just the product sitting on top of it. Use it to gently shape or shorten natural nails, to smooth hard skin, or to give a gel or acrylic surface its final finish before top coat.
This is the grit that protects the client relationship you've spent months building.
A natural nail filed with 240 grit keeps its structure appointment after appointment, which is exactly why it's the safest default whenever you're unsure how much a natural nail can handle.
What Grit Nail File Should You Use for Gel Nails?
Working on gel nails calls for more than one grit, and the file you reach for changes at every stage of the service.
Shape and structure builder gel or gel extensions with 180 grit, it's coarse enough to contour without gouging the surface. Once the shape is set, switch to 240 grit to smooth the surface and remove any texture before top coat goes on.
100 grit stays out of this process entirely unless you're removing an old set. Reach for it too early on a fresh application and you'll strip away the structure you just built rather than refine it.
That covers building and finishing a gel set. Removing one is a different job with a different grit sequence, and that's covered in the FAQs below.
What Does a 100/180 Nail File Mean?
You've already seen this logic in action with gel nails, switching grit mid-service as the job changes. Every nail file carries two numbers for the same reason, and technicians new to the trade often assume they're decorative.
They're not. When a file shows two different numbers, like 100/180, each side has its own grit. One side is stronger, one side is softer, and you're meant to use them in that order: coarse side first to remove or shape, fine side second to refine.
When the numbers match, like 240/240, both sides are the same grit level. There's no order to follow because there's nothing to switch between, just a consistent finish on either side.
Kohana's own range follows this logic across three shapes, Rectangle, Ellipse and Half Moon. The 100/180 file handles removal and everyday shaping. The 180/240 file bridges natural nail shaping with product refinement.
The 240/240 file is built entirely for natural nail and final finish work, no coarse side to worry about catching a client's skin.
Are Nail Buffers the Same as Nail Files?
A buffer and a grit chart often get lumped together, but they're not doing the same job. A file cuts down length and shapes the edge. A buffer smooths and refines a surface that's already been shaped.
That distinction matters most when it comes to natural nail preparation. Buffers aren't matte enough to prep a natural nail plate properly before product application, no matter how tempting the shortcut looks.
Use one for prep instead of a file, and you're setting product on a surface that isn't ready for it, which shows up two weeks later as lifting the client brings back to you rather than puts down to bad luck. What a buffer is genuinely good for is smoothing the nail surface before colour goes on.
In a natural nail manicure, running a standard buffer before a high gloss buffer is what gets you that final polished shine, the kind a client holds their hand out to show someone before they've even left the chair.
Frequently Asked Questions
Is 180 grit too much for natural nails?
Not necessarily, but it takes a lighter hand than 240 grit does. 180 grit can be used on strong, healthy natural nails with care. If you're working on anyone with soft, thin or damaged nails, 240 grit is the safer choice.
What grit file should you use to remove gel?
100 grit first to break the surface and remove the bulk, then 180 grit to finish smooth, keeping the 100 grit side well away from bare natural nail.
Why do my nails break after I file them?
Usually because the grit was too coarse for the job. A file that removes more material than it should leaves the nail plate thin and weak, and thin nails are the ones that peel, split and break. This isn't rare.
It's one of the most common complaints nail techs hear, and it almost always traces back to reaching for whatever file was closest rather than the one the job actually called for. Matching the grit to the task is what prevents it, and checking which side of the file you're holding takes seconds.
Will I ruin my gel nails if I file them?
Not if you use the right grit. 180 grit shapes and refines a finished gel set without damaging it, and 240 grit smooths the surface before top coat. The risk only comes from using a grit that's too coarse for gel work, or filing straight through into the natural nail underneath.
Is a higher grit nail file always better?
No. Higher grit means gentler, not universally superior. A high grit file won't remove enhancement product in any reasonable time, and a low grit file will damage a natural nail. Match the grit to the job. Not the number on the shelf.
How to Pick the Right Nail File Grit for Your Kit
Stock the three grits above and you've covered nearly every service you'll run this week. Kohana's files and buffers are built around exactly this logic, in the grits and shapes nail professionals actually reach for. You'll find the full range, files and buffers together, in the Files & Buffers collection.
