Types of tool bits and how to choose them

There are many types of tool bits indispensable for power tools that can dramatically increase work efficiency. These tool bits can be used for a variety of tasks. Although they are very useful, using an item that is not suitable for the purpose of the work will not only reduce efficiency but also affect the finished product. This article will explain typical items of tool bits and points to consider when selecting them.

What is a tool bit?


A tip tool (bit) is an attachment to the end of an electric screwdriver or router that rotates at high speed to drill holes in materials or screw in screws. They are characterized by their high versatility, as they are standardized and can be combined with various other parts. In recent years, the price of bits has become cheaper, and they are widely used in general households and for hobby and DIY.

Types of tool bits and how to choose them

There is a lineup of various items for tool bits depending on the purpose. Among the typical uses, this article will explain the following items: for tightening, drilling, and grinding.

Select for tightening

Some tool bits are used for tightening purposes, such as used for electric screwdrivers.

Phillips bit


It is a tip tool in the shape of a Phillips screwdriver, used by attaching it to an electric power tool. The size of the screw is divided into No. 3, No. 2, and No. 1, in descending order from largest to smallest. Using a screwdriver that does not match the size can cause the screw threads to be crushed, so it is necessary to have more than one screwdriver available.

Flat head bit


This is a tip tool in the shape of a flat head screwdriver. There are not many flat head screwdrivers of the same size as those used for electric power, so the need for them is not high.. There are also tool bits in which the opposite side of the Phillips screwdriver is a flat head screwdriver.

Select for drilling

Drill bits for drilling are the most frequently used tool bits (bits), and there are many types.

Drill for woodworking


It is a tip tool used for drilling holes in wood, etc. The smallest diameter is 3 mm, and the diameter increases in 0.5 mm increments up to 30 mm. Even when the diameter becomes thicker, the tip is pointed, making it easy to drill holes.

Bottom-hole cone


When viewed from the side, the tip is thin and it is used for drilling conical holes with a thick base. It is used to drill holes for wood screws and nails.

Drill for dowel


Since the tip is not pointed, it is a drill suitable for digging holes. Unlike penetrating drills, these drills are used for hollowing out a circular hole of a certain depth and size.

Countersunk cone


This is a drilling tip tool exclusively for countersunk screws, in which the screw head is like a plate. The unique shape allows you to drill a screw hole and a hole for a flat screw at the same time.

Forstner bit


Like the drill for dowels, this tool is used to drill holes for round holes at a fixed depth. It can produce a cleaner bottom surface than a drill for dowels.

Drill for ironworking


It is used to drill holes in materials such as iron and synthetic resin, which are harder than wood. It can also be used as a substitute for woodworking.

Drill for plastics


Plastics are susceptible to cracking and require the use of special drills. Usually, the drill is equipped with a circumferential blade at the tip and the second stage to prevent burrs from forming around the hole.

Drill for bamboo


Bamboo is another material with a tendency to split vertically. Drills for bamboo have a similar structure to drills for plastic, but they are also used for vinyl chloride, hard rubber, and other materials that may be damaged by woodworking or steel drills.

Select for grinding and polishing

Optional parts that enable grinding and polishing are also available for the tool bits (bits).

Grinding wheel with shaft


It is attached to the tip of a router, etc., and is rotated at high speed to polish and grind the target. In addition to regular grinding wheels, diamond and rubber materials are also available according to the hardness of the object.

Diamond grinding wheel with shaft


It is used for grinding and engraving glass, steel, and other impact-sensitive materials. Depending on the type of work to be performed, a sharp tip or a rod-shaped tip can be used.

Carbide cutters


It is used for chamfering and cutting hard materials such as iron, stainless steel and aluminum.



This bit is used to grind small parts. A disk wheel for cutting and polishing is attached to the tip of the bit.


Using tool bits correctly will increase your work efficiency many times over. For this reason, it is important to find out what types of tool bits are available and understand the characteristics of each. First of all, it is a good idea to narrow down the types of tool bits based on the purpose of use.