What Is the Echo CS-590 Chain Gauge (Spec Chart)
The Echo CS-590 uses a standard 3/8-inch chain pitch and a .050-inch (1.27 mm) chain gauge. To replace its chain, match those two measurements plus the exact drive-link count stamped or listed for your guide bar. Common bar lengths include 18, 20, and 24 inches, but length alone cannot identify the correct chain. Verify the bar before buying.
A chainsaw chain can sound like it needs a secret code. Thankfully, the code is just a few measurements. Get them right, and you can choose a compatible replacement without guessing or forcing a chain onto the bar.
Echo CS-590 chain gauge and specification chart
This chart gives the key chain-fit specifications for the CS-590. The pitch and gauge identify the chain’s basic fit, while the drive-link count identifies its length. Check the bar fitted to your saw before buying, since the count can vary with the bar.
| Specification | CS-590 requirement or check |
|---|---|
| Chain pitch | 3/8 inch, standard profile |
| Chain gauge | .050 inch (1.27 mm) |
| Drive-link count | Match the bar marking or the parts listing for that bar |
| Common bar lengths | 18, 20, or 24 inches; confirm the bar actually fitted |
| Engine displacement | 59.8 cc |
The saw’s model name does not tell you the drive-link count. Bars can differ, including replacement bars fitted after the saw was purchased. Treat the bar’s stamped details or the correct parts listing as the final check.
What does .050-inch chain gauge mean?
Chain gauge is the thickness of the chain’s drive links, the small tabs that travel inside the guide-bar groove. A .050-inch drive link measures about 1.27 mm thick. The gauge must match the bar groove so the chain can travel correctly.
A .058-inch chain is not the right match for a .050-inch bar groove. A mismatch can keep the chain from fitting or running as intended. Do not try to solve a fit problem by forcing the chain into the groove.
How is chain pitch different from gauge?
Pitch describes the spacing of the chain’s rivets. Gauge describes drive-link thickness. They are separate measurements, and both must match the bar and saw setup.
The CS-590 specification is standard 3/8-inch pitch, not 3/8-inch low-profile pitch. The names are similar, but they refer to different chain types. When ordering, look for “3/8-inch standard” along with .050-inch gauge, not just “3/8.”
How to confirm the right CS-590 replacement chain
To choose a replacement, find the guide-bar specifications and count the chain’s drive links. I recommend checking both before ordering, even when your current chain appears to be the original. A chain that matches the pitch and gauge can still be too long or too short if its drive-link count is wrong.
Read the guide-bar markings
Many guide bars have specifications stamped on the bar. Look for information showing pitch, gauge, and drive links; the layout and exact markings can vary. Clean dirt from the bar carefully so the numbers are easier to read, and do not mistake the bar’s length for its chain count.
If a marking is worn or missing, use the bar’s make and model to check its parts listing. The correct listing should identify a compatible chain or its required drive-link count. If you cannot confirm the bar, ask a dealer or parts supplier to identify it before you buy.
Count drive links when needed
Drive links are the chain’s inward-facing tabs that sit in the bar groove. If you need to count them, switch off the saw, remove the spark-plug lead as directed in the manual, and follow the manual’s safe procedure for removing the chain. Count each drive link around the full loop, not just the visible links along one side.
Do not estimate the count from bar length. Two bars with the same stated length can require different chain counts, depending on their design. When the bar listing gives a specific count, use that number.
Fit-check comparison table
| What you know | What to verify next | Why it matters |
|---|---|---|
| The saw is a CS-590 | Confirm the installed bar’s specifications | A replacement bar may differ from the original setup |
| The bar is 18, 20, or 24 inches | Find its exact drive-link count | Bar length alone does not establish chain length |
| The chain says 3/8 inch | Confirm it is standard pitch, not low-profile | Similar labels can describe different chain types |
| The chain says .050 inch | Confirm the bar groove also takes .050-inch gauge | Gauge mismatch prevents correct fit |
| All three numbers match | Check the chain and bar condition | Damage or wear can still make the setup unsafe |
Equipment Setup, Chain Fit & Safety Preparation
Correct chain fit is only one part of a safe setup. Before starting the CS-590, check the chain, bar, tension, lubrication, and safety parts. Use the operator’s manual for the model and revision you have, since it gives the steps for your specific saw.
With the engine off, confirm that the chain sits in the bar groove and that its drive links engage the sprocket as directed by the manual. Check chain tension using the manual’s method. A chain that is too loose can come off; one that is too tight can bind or wear parts faster.
Inspect the chain brake, throttle lockout, chain catcher, bar, and fasteners before work. Do not operate the saw if a safety part is damaged or disabled. Clear bystanders, plan an exit route, and check for overhead hazards, tree lean, and tension in the wood before cutting.
The CS-590 is a 59.8 cc, two-cycle saw. The specified fuel mix is 50:1 gasoline to two-cycle oil; follow your operator’s manual for the fuel and oil requirements. Fill the bar-oil reservoir as directed. Start the saw by the manual’s method, with the brake engaged when directed, and check that the chain stops at idle.
Illustrative fit-check scenarios
These examples show how to make a decision without guessing. They are not claims about a particular CS-590 owner’s setup; the bar’s own markings still decide the required chain count.
- A 20-inch bar stamped 3/8, .050: Look up the drive-link count for that exact bar. Buy a standard 3/8-inch, .050-inch chain with that count.
- A 24-inch bar with no readable stamp: Identify the bar by its make and model or ask a dealer to confirm its requirements. Do not choose a chain just because it is listed as 24 inches.
- A chain marked .058 inch: Do not fit it to a .050-inch bar groove. Find a .050-inch chain that also matches the pitch and drive-link count.
Field Cutting Operation and Worksite Controls
A correctly sized chain cannot make an unsafe cut safe. Before cutting, check the work area, use chainsaw-rated protective gear, and follow the manual. Keep your footing stable, keep the guide-bar nose clear of objects, and stop if the chain or saw behaves unexpectedly.
Use a sharp, correctly fitted chain rather than pushing a dull chain through wood. Avoid pinching the bar, and do not attempt felling techniques unless you are trained and authorized to do that work. Keep other people clear of the cutting area.
If the chain comes off, stop the engine and do not restart the saw until you find the cause. Check that pitch, gauge, and drive-link count match the bar. Also inspect for chain damage and incorrect tension. A mismatch, damaged chain, or inadequate tension can contribute to derailment and severe injury.
Maintenance, Chain Sharpening & Engine Tuning
Regular checks help you spot a fit or wear problem before the next cut. Follow the CS-590 manual for cleaning, sharpening, and service steps. If you are unsure whether a chain or bar is damaged, stop using it and have it checked by a qualified dealer or service provider.
After shutting off the saw, let it cool before cleaning or service. Clear debris from the bar groove and oil ports as the manual directs. Inspect the chain and bar for damage and wear, and check tension before use. Sharpen the chain with the correct tools and settings for that chain; do not rely on a single sharpening angle for every chain.
The stated engine speed is about 2,800 rpm at idle and 12,900 rpm at maximum no-load speed. Confirm these figures against the manual for your saw’s revision. Engine tuning should use a tachometer and the manual’s procedure, or be handled by a qualified technician. Do not adjust settings by guesswork.
Storage, Fuel Handling & Seasonal Care
Store the saw and fuel in line with the operator’s manual and local rules. Use the specified fuel mix, and never run straight gasoline in this two-cycle saw. Refuel only with the engine cool, away from ignition sources, and clean up spills before starting.
Before storing the saw, clean and inspect the bar and chain as directed. Check the chain for damage and the bar for wear, and note the bar’s specifications if they are hard to read. That record makes it easier to order the correct replacement later.
Frequently asked questions
These quick answers cover the measurements most often confused when buying a CS-590 chain. If your bar’s markings do not match a listing, pause and confirm the bar model before ordering. The fitted bar’s specifications matter more than an assumed factory setup.
What gauge chain does an Echo CS-590 use?
The CS-590 chain specification is .050-inch gauge, equal to about 1.27 mm. Confirm the installed bar is also marked for .050-inch chain, especially if the bar has been replaced.
What chain pitch does the CS-590 use?
The CS-590 uses standard 3/8-inch pitch. This is not the same as 3/8-inch low-profile chain. Confirm the full pitch description when you shop.
How many drive links does a CS-590 chain need?
There is no single drive-link count for every CS-590 setup. The required count depends on the bar. Read its marking or look up the exact bar model in the parts listing.
Can I choose a chain by bar length alone?
No. An 18-, 20-, or 24-inch bar does not, by itself, tell you the correct chain length. Match pitch, gauge, and drive-link count to the fitted bar.
Can I use a .058-inch chain on a .050-inch bar?
No. The gauge does not match. Use a chain with the gauge listed for the bar, and confirm the pitch and drive-link count as well.
Is 3/8-inch low-profile chain the same as standard 3/8-inch chain?
No. They are different chain types despite the similar names. The CS-590 specification is standard 3/8-inch pitch, so do not select low-profile chain based on the shared measurement alone.
What should I do if the bar stamp is unreadable?
Identify the bar by its make and model, then check its parts listing or ask a dealer to confirm its chain requirements. Do not guess the drive-link count from bar length.
What three specifications should I match before buying?
Match chain pitch, chain gauge, and drive-link count to the guide bar. For the CS-590, the expected chain specification is standard 3/8-inch pitch and .050-inch gauge; the count depends on the bar.
(This article was written by one of our staff writers, Evan Bradley. Visit our Meet the Team page.)
