Spiraalboren

Spiraalboren, also known as twist drills, are the most common type of drill bit used for creating round holes in various materials. They are characterized by their helical grooves, called flutes, which run along the body of the drill. These flutes serve two primary functions: they create cutting edges that remove material, and they provide a channel for the chips and debris generated during drilling to escape the hole.

The geometry of a spiraalboor is crucial to its performance. The point angle, the angle at the tip of the drill, determines how efficiently it penetrates the material and the type of hole produced. Common point angles range from 60 to 135 degrees, with sharper angles used for softer materials and wider angles for harder ones. The helix angle, the angle of the flutes, influences chip evacuation and the overall cutting action.

Spiraalboren are typically made from hardened steel. High-speed steel (HSS) is a common material, known for its durability and ability to withstand the heat generated during drilling. For drilling harder materials or for increased wear resistance, tools may be coated with materials like titanium nitride (TiN) or cobalt.

The effective use of a spiraalboor involves selecting the correct size and type for the material being drilled, using appropriate cutting speed and feed rate, and ensuring proper lubrication or coolant is applied to reduce friction and heat. Proper technique prevents tool breakage and ensures a clean, accurate hole.