Milwaukee 2727-20 & 2727-21HD Chain: Size, Part Number and Fitting

Check your bar first: 16” or 14”

Both the 2727-20 and the 2727-21HD come with a 16” bar. The 2727-20 is the bare tool. The 2727-21HD kit adds an HD12.0 battery and a rapid charger. The saw and the chain are the same.

Milwaukee’s manual covers two bar lengths for this saw, though: the 16” bar 48-09-3001 and a 14” bar 49-16-2756. Milwaukee sells the 14” version as the 2727-20C. Pitch and gauge are the same on both, 3/8” Low Profile and .043”. Only the length changes: 56 drive links on the 16” bar, 52 on the 14”. If someone has swapped bars on your saw, read the length stamped on the bar before you order.

Low Profile matters here. The manual’s spec table just says 3/8”, but Milwaukee’s chain listing names it 3/8” Low Profile and says it fits bars of the same pitch, gauge, length and drive-link count. Order Low Profile, .043” chain, not plain 3/8” chain.

Changing the chain

The bar is held by two guide bar nuts under the drive cover. The adjustment tool that undoes them clips into the bottom of the saw (manual pp. 5–6):

1. Push the hand guard forward to lock the chain brake, then take the battery out. Wear gloves.
2. Set the saw on a flat, firm surface.
3. Use the adjustment tool to remove the guide bar nuts, then lift off the drive cover.
4. Turn the chain tensioning screw counterclockwise to slacken the chain.
5. Pull the bar off its two bolts and unhook the chain from the drive hub.
6. Take the old chain out of the bar groove. Look the bar over for cracks or wear.
7. Wrap the new chain around the bar so it runs in the direction marked on the saw, and check it sits in the groove all the way around.
8. Loop the chain over the hub and fit the bar back over the bolts.
9. Refit the drive cover. Turn the tensioning screw clockwise until the chain is snug, set the tension (below), then tighten the bar nuts.

Milwaukee says it is good practice to flip the bar bottom-to-top each time you fit a sharp chain. That spreads rail wear across both edges (p. 12).

Setting tension

Pull the chain away from the bar at the middle. Tension is right when it snaps back from 1/8” (3 mm) and shows no sag. Too tight wears the chain fast and can damage the bar. A new chain stretches, so take the battery out and recheck often during the first two hours of use (p. 6).

Oiling

The tank holds 6.7 oz (200 mL). Fill it before you start, refill it when it drops below 1/4 full, and top it up after every full battery discharge. Milwaukee asks for good chain oil and suggests vegetable-based oil when pruning live trees. Don’t use waste oil, motor oil or very thick oil (pp. 4, 6–7).

To check the oiler, fill the tank, point the bar tip at a light surface and run the saw for about 30 seconds. You should see a line of oil. If not, take the bar off, clean it and its oil hole, and make sure the nose sprocket turns freely (p. 7).

When a new chain doesn’t fix it

Milwaukee’s troubleshooting table covers two common problems (p. 12):

• Bar and chain run hot or smoke: the chain is too tight, or the oil tank is empty.
• Motor runs but the chain doesn’t move: the chain is too tight, the bar and chain are put together wrong, or the bar or chain is damaged.

Replace the bar if the rails are worn so the chain leans over sideways, the rails are cracked, broken or spread, or the bar is bent. Burrs on the rails are normal wear; file them off as soon as they show up. Grease the nose sprocket through its lube hole once a week (pp. 13–14).

Milwaukee’s parts list has the sprocket as 45-44-4002. The manual gives no wear limit for it, so a Milwaukee service center is the place to have it checked.

Sharpening

Milwaukee’s manual calls for an 11/64” (4.4 mm) round file in a holder. Hold it level with the top plate at a 30° angle, and file all the cutters on one side, then the other, to the same length. The 80° side plate angle comes out right on its own when the file size is right (p. 13). Oregon lists a 4.5 mm file for its 90PX056G.

Check the depth gauges each time you sharpen. Milwaukee’s figure is .025” clearance, set with a .025” depth gauge jointer and a flat file, then round off the front of each gauge (p. 13).