A couple of years ago, I built a shelving unit for the basement using 2x4s for uprights with 3/4 inch plywood for shelves. The shelves were let into the 4 inch side of the uprights by gang routing slots into the uprights. I did not have a 3/4 inch plywood bit, so I set guides up and used a 1/2 inch bit to cut the plywood thick slots. I am now making some trivets for my Son’s new home and they call for a 1/2 inch bit. The Viper bit I used for the shelves is beyond cleaning and sharpening due the scorched pitch from the 2x4s, so it is off to HD for a new bit. Looks like I will be trying out a Freud bit.
-
Last edited by Jim Frye; 05-20-2026, 07:40 PM.Jim Frye
The Nut in the Cellar.
I've gone out to look for myself. If I return before I get back, have me wait for me. -
Are you getting a solid carbide bit with up or downcut spirals? or a conventional bit with carbide inserts?
Solid carbide upcut bit
Downcut
I suppose you know the differences and advantages?
Spiral router bits are superior to standard straight bits because they maintain constant contact with the wood, shearing the material smoothly rather than chopping at it. [1, 2, 3, 4, 5]
Key Advantages of Spiral Bits- Smoother Finish: Continuous shearing action eliminates choppy chatter marks.
- Less Tear-Out: Clean edges on veneers, plywood, and laminates.
- Faster Speeds: Effortless cutting allows quicker passes through material.
- Heat Reduction: Better physics reduce friction and prolong tool life. [1, 2, 3, 4, 5]
Upcut vs. Downcut: Choosing the Right Direction
UPCUT BIT DOWNCUT BIT
Spirals pull UPWARD Spirals push DOWNWARD
▲ [Chips Out] │ [Clean Top]
│ ▼
┌───────┐ ┌───────┐ ┌───────┐ ┌───────┐
│ Wood └───┘ Wood │ │ Wood └───┘ Wood │
└───────────────────┘ └───────────────────┘
(Clean Bottom Edge) (Clean Top Edge)
Upcut Spiral Bits (Pulls Material Up)- Best For: Mortising, deep grooving, and blind slots.
- Chip Clearance: Pulls sawdust up and out of the hole efficiently.
- Edge Quality: Perfect, clean bottom edge; risks splintering the top surface.
- Safety Note: Pulls the workpiece up toward the router motor. Always clamp material securely. [1, 2, 3, 4, 5]
Downcut Spiral Bits (Pushes Material Down) [1]- Best For: Shallow dadoes, lettering, and cutting thin veneers.
- Chip Clearance: Packs sawdust down into the cut. Avoid deep plunges.
- Edge Quality: Perfect, clean top edge; risks splintering the bottom exit hole.
- Safety Note: Pushes the workpiece down against the router table for stability.
Last edited by LCHIEN; 05-20-2026, 08:45 PM.
Loring in Katy, TX USA
If your only tool is a hammer, you tend to treat all problems as if they were nails.
BT3 FAQ - https://www.sawdustzone.org/forum/di...sked-questions
LCHIEN
Comment