I'm a beginning woodworker, and I am breaking wood screws!
After building several projects from pine, I'm now using hardwood (red oak) for the first time to build a simple desk. I'm using Dewalt countersinks (the kind with tapered bits) to drill pilot holes for the wood screws. The screws are zinc-plated #6 and #8 flathead wood screws, 1-1/2" long, purchased from either Lowes or a local hardware store. I adjusted the countersinks so that the depth of the hole beyond the countersink cutters is slightly greater than the length of the screw.
However, when I drive the screws, the head and unthreaded portion of the screws are snapping off just above the threads before the screw is fully seated. This leaves the threaded portion of the screw deep in the hole.
I started with #6 screws and broke the first 5 in a row. So I then switched to #8 and broke 2 out of the first 3. I've used both Craftsman and Black & Decker drill/drivers to drive the screws. I then drove one #8 screw by hand; it did not break, but I was not able to drive it to the full depth. Since I'm also using glue, the structure will probably be sound, but I feel like a dope because I can't drive a screw without breaking it.
In a related problem, I am getting burning of the oak when drilling the holes with the Dewalt countersinks.
So what am I doing wrong?
Poor technique?
Poor-quality screws?
Poor choice of countersinks?
All of the above?
I never had this problem when working with pine!
Thanks,
Jeff
Below you can see broken #6 and #8 screws, the one #8 screw I drove to full depth without breaking, one of the holes that happens to have a broken screw deep inside, and a Dewalt countersink that shows discoloration from the heat that was generated when drilling the holes. You'll also notice that the edges of the holes aren't very clean; is that typical of the results one can expect from these countersink bits?
Reply With Quote