When ordering tiller blades, it's important to keep in mind that there are actually two different blades on a tiller: a right-hand blade and a left-hand blade. How do you know which is which?
Step 1: Remove the tiller blade from the tiller.
Step 2: Hold the tine so that it dangles from the bolt holes.
Step 3: Holding the blade in front of you, turn it so that the cutting edge faces you. If the blade curves to the left, it's a left-hand blade. If it curves to the right, it's a right-hand blade.
The blade pictured above is a left-hand blade.
For more information about C shape and L shape tiller tines, please see the C Shape or L Shape blog post.