A:
Don't throw out your dispensrs!
I had the same question. I did some research and Uline carries the blade replacements.
http://www.uline.com/Product/Detail/H-2312-BLADE/Tape-Dispensers-Desktop/Extra-Blade-for-3M-Single-Roll-or-Definite-Length-Tape-Dispensers
Also, you can order the blade from 3M directly. Look at the base of the dispenser, there should be a Blade No. on the bottom. For Example: I have a C-25 Dispenser the Blade No. listed on the base of the dispenser is : 78-8015-6718-7.
Answered on 5/18/2011 by MK from Los Angeles, CA