Sandpaper Grit Guide: What You Need to Know
Sandpaper is an essential but often underrated tool that can help you finesse your drywall, woodworking, and metal projects. If you’ve ever tried to purchase some at your local hardware store, you’ve likely noticed that it comes in many different grit sizes, which can quickly become overwhelming. Sandpaper grit size will affect your finished project’s quality, so it’s important to know how and when to use which size.
Here’s a basic sandpaper grit guide to help you decide which grit is best for you.
What does the Sandpaper Grit Size Mean?
Contrary to popular belief, sandpaper grading size does not refer to the size of the abrasive materials but rather how many particles can fit through a 1 square inch filter. The larger the particle, the fewer can fit through at once.
Globally, the two standardized sandpaper grit charts are the Coated Abrasives Manufacturers Institute (CAMI) and the Federation of European Producers Association (FEPA). CAMI is used mainly in North America and FEPA in Europe. Sandpaper is labeled on the back with the grit size. If there is a “P” in front of the grit number, for example, P300, then you know it follows the FEPA grading system.
Sandpaper Grit Ranges
Sandpaper grit ranges can be divided into two types: micro and macro grit sandpapers. Micro grits are primarily used on wood and some drywall, whereas macro sandpapers are used on tougher metals and hardier wood because they have a more robust clearance. Below is an essential sandpaper grits guide:
Micro Sandpaper Grit Guide
Ranging from 800 to1000 CAMI or FEPA P1500, this grit has incredibly delicate abrasives and should be used in the final sanding stages or when polishing thick finishes.
Ranging from 400 – 600 CAMI or FEPA P800 – P1200, this fine-grit sandpaper slightly wipes away patches and/or minor inconsistencies but isn’t strong enough for complete removal. Superfine grit is usually used for final wood finishing.
Ranging from 360 – 320 CAMI or FEPA P400 – P600, extra-fine sandpaper should be used during the initial wood polishing stages.
With a 240 CAMI or FEPA P240 – 360, very fine sandpaper is the least abrasive and is best used when applying sanding finishes between consecutive coats when working with drywall or wood.
Macro Sandpaper Grit Guide
Coarser than very fine micro sandpaper and with a CAMI of 150 – 220 or FEPA P150 – P220, this sandpaper can be used to sand down fine wood.
Ranging from a 100 -120 CAMI or FEPA P100 – P120, this sandpaper cannot remove varnish or paint on wood and is better used to prepare wood for finishing, cleaning plaster, and removing water stains on wood.
With an 80 CAMI or FEPA P60-P80, this grit sandpaper leaves a medium to coarse surface texture after sanding. Ideally, it’s used for sanding bare wood to prepare it for removing varnish and final finishings.
Coarse sandpaper grit has a CAMI of 40 – 60 or FEPA P40-50. It removes hardy material rapidly and easily wipes away debris or helps with finishing with minimal effort.
Ranging from CAMI 21 – 36 or FEPA P12-36, an extra coarse grit removes the most material the fastest. It should be used during the initial stages of hardwood floor sanding or on surfaces that require intense treatment.
As you’ll see on any sandpaper grit size chart, the different grades of sandpaper have various quality abrasives. Most jobs require a range of grits as you progress. In addition, you’ll also have to choose between “open-coat” and “closed-coat” sandpaper.
As a rule of thumb, “open-coat” paper doesn’t clog and is usually used for wood. Sandpaper grit charts are a great tool to help you determine what kind of paper you need for the job at hand; however, they don’t always specify which grit material is best.
Sandpaper Grit vs. Material
There’s more to a sand paper grit chart than just the size of the grits. You should also be aware that there are five main types of sandpaper abrasives, all with different uses:
This common paper is used for woodworking projects. It’s primarily used in power sanders, such as an orbital sander, because of its durable nature; however, it doesn’t leave a nice finish and should only be used in the initial sanding stages.
This paper is usually dark gray or black and is used for finishing metals or “wet-sanding.” It is seldom applied to woodworking.
Garnet paper is brownish-red and commonly used in woodworking. While it doesn’t sand as fast as other papers, it leaves a better finish and is a great choice for finishing sanding.
This paper is one of the most durable and can remove large amounts of material quickly. It’s commonly used in belt sanders and can also be used for hand-shaping wood. It leaves a rough finish and should be applied with caution to veneers or plywood.
Also called flint paper, glasspaper is very light and pale yellow. It disintegrates fast and is usually used for paint removal.
The Perfect Finish
At Plastic Materials, we have an impressive range of sandpapers for every application and project, whether it’s industrial-scale or simple DIY. Give us a call, and we can help you with all your sandpaper grit guide questions. Better yet, click here to purchase the best sandpaper for your project. Our premium-grade sandpaper is guaranteed to help you achieve the perfect finish.