The bits are a tool that is not very complicated to understand since they are only used to make holes or drills. The bit itself has two main parts: the handle and the body, although the latter can be divided into other parts:
Tip angle or dead center: This part is exactly the tip of the bit
Propeller: They are called that because of the way the body of the bit has
Cutting edge: It is the highest point of the bit which begins to drill the material
Items for selecting bits
There are different types and it depends on the use that is going to be given is the type that we must use. To select the most suitable for any job we have to take into account various points such as:
Type of material to work: There are special bits for each type of material, be it wood, metal, plastic, ceramic, glass, concrete, etc.
Length and diameter: Although these two go hand in hand, the greater the diameter, the greater the length, it is very important to know the diameter measurement of the hole to be able to select the correct bit.
Cutting angle: The angle in the bits is normally 118º, although there are also 135º, they are used so that the tip makes more contact and does not slip when starting to drill.
Length of the cutting area: This is very important to consider as it is the maximum length that a bit can work.
Propeller angle: There is a nomenclature on the bits to know the type of angle and its uses for the bits.
No. 30 and is for general use
W 40 / 45º for aluminum and long chip materials
H 15 / 20º for bronze and some materials with large volume shavings
S 35º for fast chip removal, used for stainless steel
How are the bits sharpened?
To sharpen a bit we have to use emery or file and roughly cut both sides of the tip. Before starting to sharpen your bits you should know what angle your bit should take, once you know the angle you can use a piece of wood or any material, and with a goniometer, you can mark the angle to cut it and use it as a guide to Sharpen.
- drill bit drill bit angles