Maybe you have a project for one of these saws and just can't justify big money for a crankshaft. Well here is a chance to get the part for $5. Maybe you just want to keep it in inventory. Well whatever you want it is reasonable on the price and I have two. As you can see the cases are broken where the front chain catcher rides. The bearings seem good and the flywheel case half looks good also. These are 51 but I am pretty sure they will work on all the saws in this family. I may have a few other parts for this series if you need something (we can bundle). A good deal for my AS friends.