Confirmat screw spacing

Spacing guidelines for Confirmat screws in the assembly of particleboard cases. January 16, 2001

I want to assemble melamine-coated particleboard cases using Confirmat screws and butt joints. What is the optimum spacing for these screws? Has this method failed anyone?

Forum Responses
We use Confirmats for our plywood boxes, but the spacing we use would be the same for you.

On a standard base cabinet you use 5 screws for the bottom and two each for your nailer and stretchers. Because confirmats require a step drill bit for the pilot hole, you will need to purchase the Zentrix drill setup. This automatically sets the pilot hole centered on the edge of your panel, as well as the proper depth. By lining up the edge of the guide with the edge of the panel, you get the set back from the face for your front and back holes. The other holes are then spaced approximately equally.

Using this system speeds up the assembly process. Failure comes from reaming the hole out, resulting in no grab, or from not using the clutch on the driver and over-countersinking the screw, resulting in the melamine splitting.

I think that AWI requires that the Confirmats be no farther than 128 mm on center and no more than 36 mm from each edge. We typically put four in a 600 mm-deep base cabinet and three in a 305 mm-deep wall unit.

I have never had a failure. In my mind the Confirmat box is the strongest box available.

Brian Personett, forum technical advisor