When it comes to working with handheld drilling tools, some important and decisive factors must be considered to get a better result.
Read on to learn the top 3 most important things to know about drilling operations.
1. Decisive factors: Feed force, cutting speed and free speed
An ordinary human being is incapable of achieving the feed forces used, for example, in a column drilling tool, except when small bit sizes are used. In hand drilling, it is, therefore, necessary to reduce the feed force needed by selecting the correct bit and the application of a drilling technique.
The speed at which the cutting edges penetrate through the material is called the cutting speed. It is zero in the center of the hole and highest in the periphery (outer circumference), which is also where it is measured. Cutting speed is specified in meters per minute (m/min). Different types of material require different cutting speeds.
The free speed of a drilling tool is specified in a number of revolutions per minute (rpm) and is stated on the rating plate of the tool.
2. The drill bit
There are three points to keep in mind about the drill bit: the drill bit material, the drill bit surface treatment, and the drill bit type. High-speed steel is the most common material used in the manufacture of bits. Cemented-carbide bits are essential for highly abrasive materials such as composites, with reinforcement of fiber-glass, carbon fiber or kevlar fiber, to assure that they can be used for a reasonable length of time between resharpenings.
On the other hand, the steam-tempered bits have less friction due to their smoother surface, so the drilled material doesn’t stick so easily and also protects against corrosion. There are three types of drills, and the idea is that they grind in different ways: jobber drill, quick spiral drill, and slow spiral drill. What varies here is the angle and the material they are recommended for.
3. The drilling tool
When it comes to handheld drilling operations, it is required to have speed and precision. The machines also must be light and strong in order to avoid operator fatigue. Pneumatic drills are compact and lightweight so they are easy to hold and adapted to the hand and arm anatomy.
There are basically 4 different types of drills:
3. Angle drills
4. and screw-feed drills.
Each specific type of drill is appropriate for the operator’s working environment and it influences ergonomics for the operator directly.
Uncomfortable working postures are common in handheld drilling operations, but this problem can often be avoided by using the right type of tool.
Key takeways
- When drilling in a high position, use a straight drilling tool
- When drilling in a low position, use a pistol grip drilling tool
To learn more or schedule a product demonstration, contact Atlas Copco today.