Changing Blades, Chains, Discs and Cut-Off Wheels (and Which Way to Turn)

Your manual wins. These are general practices. When your tool's manual says something different, follow the manual.

Always first: remove the battery or unplug the tool, and for gas tools stop the engine and engage the chain brake. Wear cut-resistant gloves when handling blades and chains.

Which way do I turn it?

• Most fasteners: righty-tighty, lefty-loosey (clockwise tightens).
• Saw arbor bolts: to loosen, turn the bolt the same direction the blade spins (follow the rotation arrow on the guard). Saws are built so the blade's own spin keeps the bolt tight. Many miter saws and some circular saws use left-hand threads, and this rule works for both.
• Angle grinder spindle nuts: standard threads. Press the spindle lock and turn the flange nut counterclockwise to loosen.
• Pedals on bikes, some mower blade bolts and some fan blades also use left-hand threads. If it won't budge, check the manual before you strip it.

Chainsaw chain

1. Engage the chain brake. Loosen the bar nuts (counterclockwise) and back off the tension screw.
2. Remove the side cover, bar and old chain.
3. Lay the new chain on the bar with the cutters on top pointing toward the tip of the bar, away from the saw.
4. Fit the drive links into the bar groove and the chain onto the drive sprocket. Refit the bar and cover finger-tight.
5. Tension: lift the bar tip and turn the tension screw until the chain sits snug along the bottom of the bar but still pulls around by hand (with gloves). Then tighten the bar nuts while holding the tip up.
6. Check tension again after the first few cuts; new chains stretch. Set tension on a cool chain.

Portable band saw blade

1. Release the tension lever.
2. Slide the old blade off both wheels and out of the guides.
3. Fit the new blade with the teeth pointing in the direction of travel into the cut (match the arrow on the saw).
4. Seat it in the guide bearings and around both wheels, then re-tension. Run it briefly to check it tracks on the wheels.

Angle grinder disc

1. Press the spindle lock and remove the outer flange nut with the spanner wrench.
2. Mount the disc with the correct guard in place. The guard sits between you and the disc.
3. Check the disc's maximum RPM is at or above the grinder's RPM. Never put a saw blade or a disc rated below the grinder's speed on a grinder.
4. Snug the flange nut, release the lock, and run the grinder for 30 seconds pointed away from people before cutting.

Cut-off wheel

• Cut-off wheels (thin Type 1 or Type 41 wheels) need a cutting guard (Type 1 guard) on most grinders.
• Cut straight in. Never grind with the side of a cut-off wheel; it can shatter.
• Replace a wheel that is chipped, cracked or was dropped.

Circular saw blade

1. Press the arbor lock and loosen the arbor bolt with the blade wrench (same direction the blade spins).
2. Remove the outer washer and old blade. Clean pitch off the washers.
3. Fit the new blade with the teeth at the bottom pointing toward the front of the saw. The arrow on the blade matches the arrow on the guard.
4. Refit the washer and bolt, then tighten. Check the lower guard snaps back freely.

Which blade for which job