About the K-917 replacement blade.
The K-917 blade is 3/4 x 1 1/2 which is the same size as the K-9 blade. It also fits in the MS25, MS27 and MS20 KuttO safety box cutters.
The K-9 blade is named after it's thickness .009" thick. The K-17 is also named after it's thickness of .017". The K-917 is a combination of both. It's size is the same as the K9 blade but it is thicker and more heavy duty as is the K-17 Blade.
Please check out our blades page at http://www.modernspecialties.com/blades/blades.html or give us a call at 1-800-648-5801 for more information.