A craft knife can be separated into two main parts – the blade and the handle.
Blade
The blade of a craft knife is usually made from steel.
Steel is a material often used in the manufacturing of tools due to its strength and comparatively low cost.
The steel used is often heat treated, to bring the blade to a hardened state. This makes it hard enough to use for tough cutting applications, but not so hard that it loses its flexibility and breaks.
Handle
A craft knife handle can be made from a range of materials, including plastic, rubber, metal and wood.
Plastic
The most common material used for the handle is plastic. It can be ergonomically shaped in various ways to provide both a comfortable and secure grip for the user.
Rubber
Rubber is also often used for the craft knife handle as it has similar qualities to plastic, in that it can provide a soft, comfortable grip for the user.
Aluminium
Aluminium has many advantages, including its strength and durability. However, it may be less comfortable to hold than handles made from plastic or rubber.
Wood
Finally, a handle can be made from wood, although it is less commonly used than the other types of materials. Wood is relatively lightweight, is easy to shape and some people prefer it because of its natural look and feel.