Upward spiral is perfect for ejecting chips from mortises. It's also the ideal bit for pattern routing because when using a guide bushing the best face goes down and templates are attached to the top side. 1/2" shank.
Application: Cutting mortises and routing deep blind holes
Freud's solid carbide up spiral bits combine effective chip removal with a cut that can't be matched by standard straight bits. Ideal for production settings.
Excellent for grooves and dadoes in all composite materials, plywoods, hardwoods and softwoods.
Use on CNC and other automatic routers as well as hand-held and table-mounted portable routers.
I had to rout 30 8" circles in MDF for a fund raiser. (table decorations.) I tried a straight bit. Overheated and very slow This worked wonderfully. Clean cuts. No overheating. Edges didn't even require touch-up sanding.
Works well for deep plunge cuts but broke when extending a dado in my router table. I am now plunge-cutting the entire length of the dado with a hand-held plunge router and cleaning up the cut after most of the material is removed.