Gary, there are many variables on bars and chains but the biggies are:
- chain pitch = measure between any 3 rivet centerlines and divide by 2. Common for smaller saws are 3/8" and .325" pitch
- chain gauge = this is the width of the driver link and slot that goes around circumference of bar needs to match. Common size on smaller saw is .050"
- length = bar length is in inches, so your bar is probably 14, 16, or 18" but chain is usually measured by the number of Drive Links (DL) needed to make a loop
The easy way is to remove the bar and look for this info to be stamped on the side of bar where it mounts over the two studs on the saw or just take the bar with you to saw shop, Lowes, WallMart, or Home Depot. (You will want to take it off and clean it up anyway, especially clean the groove out.)
RavensRoost