In a hurry? Here's the quick guide

I've been sharpening garden tools for over a decade, and I still reach for sandpaper when my shears go dull. It's cheap, effective, and you probably have a sheet lying around. In this guide I'll walk you through exactly how to do it, what grit to use, and the mistakes that even seasoned gardeners make.

Why Sandpaper Works for Sharpening Shears

Sandpaper is essentially abrasive grains glued to a backing. When you rub it against the blade's edge, it removes tiny amounts of metal, creating a new, sharp edge. It's not as aggressive as a file, which is actually a good thing for shears—you're less likely to overheat or damage the blade. Plus, sandpaper conforms to curved edges (like pruning shears) better than a flat file.

I've tried diamond stones, whetstones, and even power grinders, but for quick maintenance, sandpaper wins. The trick is matching the grit to the blade condition. Let me break that down.

What You'll Need

Sandpaper Grit Guide

Blade ConditionRecommended GritPurpose
Very dull or nicked80-120Coarse removal of metal
Slightly dull150-220General sharpening
Finishing / honing400-600Polishing edge, removing burr

I keep a three-pack: 120, 220, and 400. That covers almost everything. For very damaged blades, start with 80, but go easy—you don't want to eat away too much metal.

Other Supplies

  • Lubricant – WD-40 or light oil; prevents clogging and makes the sandpaper last longer.
  • Cloth or paper towel – to wipe clean.
  • Safety glasses – metal filings fly everywhere.
  • Gloves – optional, but sandpaper can chew up your fingers.
Pro tip: Cut the sandpaper into strips about 2 inches wide. It's easier to control, and you can use each side until it's clogged.

Step-by-Step: How to Sharpen Garden Shears with Sandpaper

Step 1: Clean the Blades

Dirt and sap will ruin your sharpening. Wipe the blades with a rag soaked in soapy water. For sticky residue, use a little rubbing alcohol. Dry completely.

Step 2: Secure the Shears

Open the shears as wide as they'll go. If you have a vise or clamps, use them to hold the shears steady. Otherwise, you can brace the handle against your workbench. The blade needs to be immobile.

Step 3: Choose the Right Grit

Start with 120 grit if the blade is very dull. If it's only moderately dull, go straight to 220. I once made the mistake of using 80 grit on a pair that just needed a touch-up—ended up with a rough edge that took forever to smooth out.

Step 4: The Sharpening Motion

This is where most people mess up. You need to match the blade's existing bevel angle. On most garden shears, the bevel is around 20-25 degrees. Hold the sandpaper flat against that bevel and pull it from the pivot (the screw) toward the tip. One direction only – never back and forth like a saw; that'll round the edge.

Apply moderate pressure and make about 10-15 strokes. Check the edge: you should see a bright, clean line. If there's a burr (a tiny ridge of metal on the unsharpened side), flip the blade and lightly sand the back with the same grit to remove it.

Common blunder: Lifting the sandpaper at the end of each stroke. Keep it flat until you pass the tip. Otherwise you'll round the tip and the shears won't cut cleanly.

Step 5: Test and Hone

Wipe the blade clean. Try cutting a piece of paper – it should slice cleanly, not tear. If it still struggles, repeat with the same grit. Once sharp, switch to 400 grit and make 5-6 light strokes to polish the edge. This removes microscopic burrs and makes the edge last longer.

I usually finish by stropping on old denim or leather with a little honing compound, but that's optional. Even without it, the shears will be noticeably sharper.

Common Mistakes to Avoid

  • Using too coarse a grit from the start – unnecessarily shortens blade life.
  • Sandpaper too dry – always use a drop of oil to keep the paper from clogging.
  • Ignoring the other blade – most shears have a bevel on only one side; the other side is flat. The flat side should be deburred but never sharpened.
  • Over-sharpening – you don't need a razor edge for pruning. A slightly duller edge is actually more durable.
  • Skipping the cleaning step – sap acts like a sandpaper clogger and you'll waste material.

How to Keep Blades Sharp Longer

After sharpening, oil the pivot point and store the shears in a dry place. I like to apply a thin coat of mineral oil to the blades – prevents rust and makes the next sharpening easier. Also, avoid cutting wire or dirty branches; that's what loppers are for.

I sharpen my shears about twice a season, but if I'm pruning a lot, I'll do a quick pass with 400 grit every few weeks. It only takes two minutes if you keep up.

Frequently Asked Questions

I've heard sandpaper leaves an uneven edge compared to a file. Is that true?
It can if you don't keep the sandpaper flat against the bevel. But with practice, sandpaper actually gives a smoother finish because it's more flexible. The key is using a backing pad (like a small block of wood) to keep the paper flat. I rarely use a file anymore – sandpaper gives me more control.
What's the best way to sharpen curved pruning shears with sandpaper?
Fold the sandpaper into a narrow strip and use it like a shoe-shine motion, following the curve. Start from the pivot and pull toward the tip while slightly rotating your wrist to match the arc. It's a bit tricky, but still faster than trying to use a stone.
My shears won't cut after sharpening – what did I do wrong?
You probably created a burr that's blocking the two blades from meeting. Check the flat side: if you feel a rough edge, deburr it by laying the flat side flat on 600 grit sandpaper and giving it a few light passes. Also ensure the pivot bolt is tight – loose shears won't cut regardless of sharpness.
Can I use wet/dry sandpaper with water instead of oil?
Yes, but water increases the risk of rust if you don't dry the blades immediately. I prefer oil (mineral or honing oil) because it stays on the surface and provides better lubrication. If you use water, at least add a drop of dish soap to reduce friction.

Fact-checked against common sharpening practices from the American Horticultural Society.