I am interested in buying a flush trim bit to flush up face frames on furniture carcasses. Which would be a better bit - a straight cut or a shear cut? It will be used mostly on 3/4" stock. Poplar and hardwoods.
- Ken J.
Lake Ronkonkoma, NY
I am interested in buying a flush trim bit to flush up face frames on furniture carcasses. Which would be a better bit - a straight cut or a shear cut? It will be used mostly on 3/4" stock. Poplar and hardwoods.
- Ken J.
Lake Ronkonkoma, NY
Our Expert
Many pieces of fine furniture incorporate a face frame glued to the edges of a dovetailed box. Although dovetailed casework is strong, a face frame eliminates the possibility of racking while providing a stile-and-rail framework on which to hang the doors.
The stiles and rails of the face frame are assembled with mortise-and-tenon joints and then glued to the edges of the box. A simple butt joint works fine because the mating surfaces are long-grain. Rather than attempt to make the frame flush with the box it is much easier and more efficient to make the frame slightly oversized, by approximately 1/32", and flush trim it after assembly.
You have three choices of flush trim bits: The standard bit, such as Amana Tool no.47101 is a good general purpose bit. The two-flute design will provide a fast cut and a good finish. I use this type of bit whenever I'm making jigs and fixtures or flush-trimming a curved molding before shaping it with profile bits.
In order to avoid the possibility of tearout when flush-trimming figured woods or when trimming against the direction of the grain I recommend the Amana Super-Trim. The 3 degree shear angle coupled with the large diameter create a very fine surface. I suggest a bit such as the Amana no.47135 Down Shear.
Highly figured woods such as tiger maple are especially prone to tearout.
For these situations I recommend one of the Ultratrim solid carbide spiral bits - Amana no.46400. The spiral flutes cut incredibly smooth and virtually eliminate the possibility of tearout.
Also, when flush trimming, keep in mind that you'll get the best results with the shortest bit.