How to Sharpen Reel Mower Blades for Best Results
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Reel mower sharpening is the job of keeping the spinning reel blades sharp so they slice grass against the fixed bedknife instead of tearing it. A reel mower cuts like a pair of scissors, so a clean result depends on two things working together: sharp reel blades and the right small gap between the reel and the bedknife. This guide explains what to check, what to adjust, and when to stop and get a shop involved. It also covers the four reel models in our product data, with the blade and height details each listing states.
Quick answer
- A reel mower gives a clean cut when the reel blades are sharp and the reel is set correctly against the bedknife.
- The reel should not press hard on the bedknife, because contact greatly increases the work the mower needs. A gap smaller than the grass blade’s thickness still cuts cleanly.
- If the gap is too large, grass slips through uncut. Adjust the cutting height using the mower’s lever or wheel mechanism.
- Follow the owner’s manual for the exact sharpening and adjustment steps. The reference we checked does not cover sharpening procedure.
How a reel mower cuts grass
A reel mower has a fixed horizontal bedknife set at the height you want to cut. A fast-spinning reel of helical blades sweeps past it, and each blade forces the grass against the bedknife and snips it. Because the cut happens between two edges, the sharpness of both matters, and the gap between them matters even more. The reference we checked, the Wikipedia article on lawn mowers, explains that a well-adjusted reel mower makes a clean cut, and that a clean cut helps grass recover more quickly.
The same reference explains the gap in simple terms. The reel does not need to touch the bedknife. Contact greatly increases the work the mower requires, which makes it harder to push and wears the parts faster. If the gap is smaller than the thickness of a grass blade, a clean cut still happens without extra friction. If the gap is larger than the grass blade’s thickness, grass slips through and is not cut. That is why a reel mower that looks sharp can still give a poor result when the reel is out of adjustment.
Signs the blades need attention
You do not need a gauge to notice that a reel mower is cutting poorly. Watch the lawn after a pass. A reel that cuts cleanly leaves a neat edge on each blade of grass. If the grass looks torn, frayed or ragged, or if the tips turn brown quickly after mowing, the blades or the reel-to-bedknife setting are the first things to check. Uncut grass that bends over instead of being cut points to a gap that is too large, a bedknife that needs attention, or a height that is set too low for the mower’s ability.
Check for physical damage before you run the mower again. A bent reel blade, a chipped bedknife or a loose part should be looked at before any sharpening work. If you find damage you are not sure how to repair, a qualified small-engine or lawn equipment shop can inspect the mower. This is the right step for any part that is bent, cracked or loose, because forcing a damaged reel can strain the mower and injure you.
Safety first
A reel mower has no engine or battery, so it does not start by accident. The reel is still sharp, though, and it spins when the wheels turn. Before any sharpening work, stand the mower on a stable, flat surface, keep the wheels from rolling, and keep your hands and feet well clear of the reel and bedknife. Wear heavy work gloves when you reach near the cutting parts. Never reach into the reel while someone is pushing the mower or while the wheels could turn. If you are unsure how to safely handle a blade, leave the work to a shop. The same care applies to children and pets, so keep them well away from the mower while you work. Our lawn mower safety checklist for homeowners covers the basics.
Step-by-step approach
Work through the mower in this order. The owner’s manual for your model gives the exact steps, and the order below keeps you from making the setting worse while you work.
- Clean the mower. Remove grass, mud and debris from the reel and bedknife so you can see the actual edges. Dried clippings can hide a dull blade or a bent part.
- Inspect the reel and bedknife. Look for bends, chips and wear. Note which blades look dull and whether the bedknife edge is worn.
- Set the height. Choose the cutting height first, because the reel-to-bedknife relationship depends on it. The height is changed by a master lever or by wheel mechanisms, depending on the model.
- Check the gap. The reel should sit close to the bedknife without rubbing hard. A good test is whether the reel turns freely by hand and whether a sheet of paper or a feeler gauge slips between the parts without a lot of force. Adjust only as your manual describes.
- Sharpen the reel blades. Sharpen according to the method your manual gives. Keep the blade edges even so the reel stays balanced and the cut is consistent across the width.
- Test the cut. Mow a small area on dry grass, then look at the cut. If grass is still tearing, return to the gap check before you sharpen more.
Keep the cutting height in mind as you test. The Wikipedia reference describes the height as set by a master lever or by wheel mechanisms, and that matches the adjustment choices you will see on the reel models in our data.
Models in our data and what their listings state
These four reel mowers are the models in our product data. Each listing states different blade and height details, so the table shows what each one says and leaves blanks where the listing is silent.
| Model | Cutting width | Blades | Height range stated | Blade material or claim | Weight stated |
|---|---|---|---|---|---|
| American Lawn Mower 1204-14 | 14 inches | 4 blades | Bullets: 0.5 to 1.75 inches. Specs: 1.3 to 4.45 inches. | Alloy steel | Bullets: 19 pounds. Specs: 1 kg. |
| American Lawn Mower 1815-18 | 18 inches | 5 blades in the title | Bullets: 1/2 to 2-3/4 inches. Specs: 1.27 to 6.4 inches. | Metal | 27 pounds |
| Great States 304-14 | 14 inches | 5 blades | 0.5 to 1.75 inches | Heat-treated alloy steel, which the listing says helps blades stay sharp longer | 9.3 pounds |
| Scotts 304-14S | 14 inches (listed as 35.6 centimeters) | 5 blades | 0.5 to 1.75 inches | Heat-treated alloy steel, which the listing says helps blades stay sharp longer | 18.1 pounds |
The American 1204-14 listing gives two different height ranges and two different weights, so confirm the figures on the product page before you set the mower. The Great States and Scotts listings describe the same 14-inch, 5-blade style with the same height range. The Scotts listing gives its cutting width in centimeters, which converts to the same 14 inches. The listings do not state how often a blade should be sharpened, and they do not give a sharpening procedure, so use your manual for that.
For a reel that cuts a wider path, the American 1815-18 is the largest in the group at 18 inches. Its listing says it suits smaller and medium yards and works best on dry grass under 4 inches. Its bullets describe a 5-year protection plan, while its specs field gives a 1-year limited warranty, so check the warranty terms before you buy.
If you want a lighter reel that is easy to handle, the Great States listing gives the lightest weight in the group at 9.3 pounds. Its bullets say the quiet operation needs no gas or oil and that the handle is cushioned. Our guide to blade styles for lawn mowers explains how reel blades compare with rotary, mulching and flail designs.
View the American 1204-14 on Amazon
View the Great States 304-14 on Amazon
View the Scotts 304-14S on Amazon
Common mistakes that make a reel cut poorly
- Setting the reel against the bedknife too tightly. Contact greatly increases the work the mower requires, so the mower feels hard to push and the cut suffers.
- Leaving the gap too wide. When the gap is bigger than a grass blade’s thickness, grass slips through uncut.
- Sharpening without checking the setting. Even very sharp blades will not cut cleanly if the reel and bedknife are out of adjustment.
- Cutting grass that is too tall. The American 1204-14 listing says reel mowers are less effective on taller grass. Mow more often and overlap passes when grass is 4 inches or taller.
- Ignoring bent or cracked parts. Damage needs a shop, not a quick fix in the yard.
When to stop and call a shop
Stop and call a qualified lawn equipment shop if a blade is bent, a bedknife is chipped or cracked, a part is loose, or you cannot set the gap to match the manual. A shop can check the alignment and the reel’s balance, which are hard to judge at home. This is also the right call if you are not comfortable working near the reel. Asking for help is a normal part of keeping a reel mower in good shape.
FAQ
How often should I sharpen a reel mower?
The sources and listings in our data do not give a fixed schedule. Check the cut after each mowing. When grass tears or turns brown at the tips, look at the blades and the gap first, and sharpen as your owner’s manual describes.
Why does my reel mower leave ragged grass tips?
Ragged tips usually mean the reel blades are dull or the gap between the reel and bedknife is not set correctly. A clean cut depends on both, so check the setting as well as the sharpness.
Should the reel touch the bedknife?
No. The reference we checked says the reel does not need to touch the bedknife, and contact greatly increases the work the mower requires. A small gap that is smaller than a grass blade’s thickness cuts cleanly.
Can I adjust the cutting height and the gap together?
Set the cutting height first, then check the gap. The height is changed by a master lever or wheel mechanisms, depending on the model, so follow your manual for the order of adjustments.
Which reel mower in our data has the lightest weight?
The Great States 304-14 listing states the lowest weight in the group at 9.3 pounds. The Scotts 304-14S states 18.1 pounds, and the American 1815-18 states 27 pounds.
Bottom line
Reel mower sharpening works best when you treat the blades and the reel-to-bedknife setting as one job. Clean the mower, inspect for damage, set the height, check the gap and then sharpen according to your manual. Test the cut on a small area before you mow the whole lawn. If the parts are bent or the adjustment will not come right, take the mower to a shop. For more on keeping a mower running well, read our guide on replacement mower blades and the reel and robot mowers listed beside them.
Sources
Lawn mower, Wikipedia (reel mower cutting action, reel and bedknife gap, and height adjustment)
