How Do I Know What Size Bar I Have?
Your bar's cutting length (or "called length") is different from its total or overall length. The cutting length is the distance from the front of the saw to the tip of the farthest cutter, rounded to the nearest inch. This called length is the number used in the selector guide to describe the bars that are available for your saw. Be careful; a bar made by OREGON® may take a different drive link count than that of another producer. Here’s a tip: if you have an OREGON® bar, look at the ten-digit number stamped on the motor end; the first two digits, such as 16, tell you the called length.

Consumer Chain uses a letter system. Please see table below for more information:

Once you know the make, model, and bar length, there are some other features you need to know, such as:

What is Chain Pitch?
Chain Pitch is the size of the chain, and is defined as the distance between any three consecutive rivets divided by two. OREGON® chain is made in several pitches - 1/4" is the smallest, 3/8" is the most popular, 3/4” is the largest. Pitch is important because the drive sprocket must be the same pitch as the chain, and if applicable, the bar nose sprocket. The easiest way to determine the pitch of your chain is to look at the number stamped on the drive link.See the chain-pitch-and-gauge chart below.

What is Chain Gauge?
Chain Gauge is the Drive Link's thickness where it fits into the bar groove. The gauge of the chain and the gauge of the bar must match. OREGON® has several gauges for chainsaws - such as, .043”, .050", .058” and .063". Normal wear can make it difficult to accurately measure chain gauge on a worn chain. Always order by the number stamped on the drive link of your old chain to assure correct gauge. See the chain-pitch-and-gauge chart below.

How do I measure the length of my chain?
The length of your chain is determined by counting the number of drive links in your chain. Your drive link count has a direct correlation to your bar’s length. Be careful; a bar made by OREGON® may take a different drive link count than that of another producer. Here’s a tip: count the number of drive links in the chain you have now, and write that number down someplace where you can find it. Or, if you have an OREGON® chain, the drive link count is stamped on the gold ID link; you can refer to that gold ID link for future reference.

What is the drive sprocket?
The sprocket and the clutch drum are connected to the saw motor.The sprocket is designed to drive the proper-pitched chain around the guide bar.

What is ANSI?
Certain provisions of the safety standard known as the "ANSI (American National Standards Institute) B175.1" contain requirements designed to reduce the risk of injury from chainsaws sold in the United States. The following information should be used as a guide for the selection of appropriate replacement chains and guide bars in order to maintain compliance with the ANSI standard (United States only).

The ANSI standard B175.1 divides all chainsaw power heads into two groups:
- Under 3.8 cubic-inch (62cc) engine displacement, the chain meets the standard and is identified by green markings or labels.
- 3.8 cubic inch (62cc) and larger, the chain DOES NOT meet the standard and is identified by yellow markings or labels.

Saws 3.8 cubic inches (62cc) and larger may, but are not required to, comply with ANSI low-kick-back provisions. These saws are not recommended for general use and may be capable of kickback that could result in serious injury. Larger saws should be operated by users with experience and/or specialized training for dealing with kickback.

When replacing chain on saws less than 3.8 cubic inches (62cc), any low-kickback chain of the proper pitch and gauge can be used. OREGON® identifies and labels all low-kickback chain in green. OREGON® safety features greatly reduce the hazard of kickback while maintaining high cutting performance. However, ALL CHAINS CAN KICKBACK, which may result in severe personal injury to the saw operator or bystander.