3/8 Vs. .325 Chain Saw Chain

Chain Pitch

• One of the most important measurements chain manufacturers use to distinguish different sized chains is the chain’s pitch. The chain’s pitch measures the distance between any three consecutive rivets divided by two. This measurement sets the distance between the chain links and determines the size of the chain. The pitch on the chain must match exactly to the pitch of the drive sprocket on the clutch, and for those saws that use a nose sprocket, the pitch of the nose sprocket as well.

3/8 Inch Chain

• For most chain saws, 3/8 inch chains are some of the most popular and most frequently used. These chains will fit a wide variety of professional and moderate use chain saws. Some 3/8 inch pitch chains offer a low-profile feature. These chains push out a smaller amount of wood and therefore require less engine power to slice through wood. Since these chains require less power, it’s customary to see them on chain saws with guide bars smaller than 18 inches.

.325 Inch Chain

• Chains with a pitch of .325 are just slightly smaller than chains with 3/8 inch pitch. Most of the time, chain saws that can operate chains with a 3/8 inch pitch will also be able to operate chains with a .325 inch pitch. Again, the size of the kerf, which is the width of the saw cut, is smaller than on heavy-duty professional chain saws, and it is ideal for chain saws with guide bars that are less than 20 inches, with 18 inch guide bars being ideal.

Why it Matters

• The reason these small differences in measurement matter are due to the drive sprocket in the clutch and the sprocket on the nose of the guide bar. If the chain’s pitch doesn’t match precisely to the drive sprocket and the nose sprocket, the chain won’t ride smoothly around, making cutting difficult and even dangerous. The pitch of the chain can be difficult to accurately measure, so the operator should look for the identifying pitch numbers, located either on the guide bar or in the chain saws operator’s manual.