Now, Dispozablade’s Self-Set system makes installing the knives foolproof. With a start-up kit you get three knives and three holders, with locating tabs for positioning on the cutterhead. After removing your old knives and jack screws—you won’t need them anymore—mount a knife onto a holder, and place it in the cutterhead slot, with the tabs resting on the cutterhead, as shown at right. Tighten the gib bolts to secure the knives and holders. That’s it. No knife-setting jig, no jacking around with jack screws. If you nick the knives, simply loosen the gib bolts and shift one knife to offset the nicks. Because the knives have dual cutting edges, you can flip them when they become dull. (As with disposable planer knives, we don’t recommend resharpening them because it’s difficult to achieve identical grindings.) High-speed-steel replacement knives cost from $25 to $70 for a set of three at the time of our tests. Dispozablade also sells cobalt knives in three-packs. They are similar to carbide, meaning they maintain sharp edges longer but prove more brittle. Self-Set knives do not fit all jointers and planers, as we found on those with cutterheads that have rounded edges where the tabs rest. Call Dispozablade to see whether Self-Set knives will work on your machine. (They prefer to talk with customers rather than listing all tool matches on their Web site.)