Drilling at an angle can seem difficult, but don't worry, there's several methods you can use to create angled holes. You can try some basic tricks if you don't need your angles to be too exact. Otherwise, try building an angled jig with a piece of wood for your hand drill, or creating an angled jig that fits onto the plate of your drill press.

• Method #1 Use a trepanning tool
• Method #2 Enlarge the hole with a boring tool
• Method #3 Use helical interpolation with milling tools

Drilling very large holes greater than 1 1/2 inches with a standard bit is impractical as you would need a drill with a huge amount of power and torque to overcome friction in order to drill through timber. Instead, drilling large holes can be accomplished with a hole saw. This has small teeth like a handsaw and the "blade" is in the form of a cylinder.

Some hole saws are only designed for drilling wood or plastic while other versions are made from HSS steel and suitable for drilling iron, steel and other metals in addition to wood.

With a good hammer drill and concrete drill bits, making holes in concrete is almost as easy as drilling in wood. The hammering action of the masonry bits pulverizes the masonry in contact with the tip of the bit.

Rotary hammers are more powerful, though, and have a “hammer-only” mode with no rotation. This is also known as ‘rotary stop’ or ‘chisel’ mode. The rotary motion of the drill is switched off and the hammer action only is applied. The piston inside moves back and forth driving the drill bit back and forth, driving it in turn into the material

The pounding power of a hammer drill is measured in BPM (beats/blows per minute)

Masonry bits are available with a round section shank for use in a conventional chuck. However, a better choice is an SDS type bit. The shank on this type of bit doesn't slip in a chuck and can be quickly inserted and extracted from the SDS chuck on the power drill.

Drilling through concrete is tough to begin with, but when your masonry drill bit encounters a piece of rebar the project comes to a screeching halt. Masonry drill bits are coated with mineral grit; they pound and grind through brick and cement-based materials. Although abrasive bits are capable of grinding through steel rebar, sharp-edged drill bits are faster and more effective

Because builders don't leave any indication of the location of rebar, there's always a chance that your concrete drill bit will encounter metal. When your concrete drill bit (hammer bit) hits rebar, you should stop drilling and replace the concrete bit with a metal bit (rebar bit). Once you clear the metal, you can reattach the concrete bit and continue drilling through the masonry material.

With some skill, you can learn to sharpen a drill bit on the fine grit wheel of a bench grinder. However the bit needs to be held to the wheel at a relatively precise angle, which takes a bit of practice

An alternative is to use a sharpening tool like this one by Drill Doctor. These machines are basically composed of a motor driving a small grindstone. To sharpen a drill, you insert it in the appropriate sized hole in the top of the sharpening tool and twist it a few times. This product covers all sizes up to 12 mm or 1/2 inches

A great number of holes with small diameters of about 1 mm or less must be drilled in printed circuit boards (PCBs) used by electronic equipment with through-hole components. Most PCBs are made of highly abrasive fiberglass, which quickly wears steel bits, especially given the hundreds or thousands of holes on most circuit boards. To solve this problem, solid tungsten carbide twist bits, which drill quickly through the board while providing a moderately long life, are almost always used