Upcut router bits have a spiral flute that pulls cut material upward and out of the cut as the bit spins. It’s the opposite of a downcut bit, and it’s the most common spiral bit design. Use an upcut when chip clearing and cutting speed matter most, and the top surface isn’t critical. If the visible face matters, switch to a downcut or compression bit. Upcut bits feature:

• Excellent chip evacuation. Chips are lifted out of the slot, which keeps the cut clear, reduces heat, and extends bit life.
• Faster, cooler cutting. Because the bit isn’t re-cutting packed chips, you can often feed faster without burning.
• Great for deep cuts. Mortises, deep grooves, and thick stock are where upcuts do best.

Canadian Woodworker stocks and sells a wide variety of upcut router bits from Stinger, CMT and Royce-Ayr.