Screw Size: 12 Clearance Hole: 7/32 Pilot Hole, Softwood: 7/64 Pilot Hole, Hardwood: 1/8 Countersink vs Counterbore The most common screw used today to join wood is the flat-head screw.

And by boring pilot holes prior to screw driving, you'll avoid splitting the wood. Drill-and-drive bits are available from most power tool manufacturers, including DeWalt, Ryobi, and Craftsman ...

Most are specified as 125 or 140-ksi nuts. Some anchor, swivel, variable-counterbore and channel designs are rated at 160 ksi, and specials to 180 ksi.

A new insight from our frequent correspondent begins: “Some times we need to machine or countersink holes with accuracy that keeps the dimension M of the plane A. in these cases, we use a countersink ...

I need to make a lot of countersink holes in masonite, hence the requirement for durability and cheapness (since anything will dull quickly anyway).<BR><BR>My eternal gratitude to anyone who can ...