Drilling Flashcards
What is the primary purpose of drilling?
To create cylindrical or threaded holes in a workpiece.
What are the two main types of holes in drilling?
Through-hole and Blind hole.
What is solid drilling?
A method where the hole is drilled in solid material to a predetermined diameter in a single operation.
What is the function of reaming?
To finish a drilled hole by smoothing the surface and ensuring accurate size and shape.
What are the typical motions in a drilling operation?
A rotating tool combined with a linear feed movement.
What is the main difference between countersinking and counterboring?
Countersinking creates a tapered feature for flathead screws; Counterboring enlarges a hole with a flat bottom.
What is the feed per revolution (f_n)?
The axial movement of the tool during one revolution, used to calculate the penetration rate.
What are the three types of taps commonly used for threading holes?
- Taper Tap: Ideal for starting threads in hard materials.
- Plug Tap: Used for creating deeper and more precise threads.
- Bottoming Tap: Used for threading to the bottom of a hole.
What is trepanning, and why is it used?
A process for creating large holes by cutting only the periphery, leaving a core, to reduce power consumption.
What are some common challenges in deep-hole drilling?
- Chip evacuation
- Tool deflection and instability
- Overheating
- Ovalization of the hole
What is the main advantage of the Ejector System in deep-hole drilling?
It does not require sealing and allows for efficient chip evacuation through the interior of the drill.
What is the cutting speed (V_c) at the center of a drill?
The cutting speed is zero at the center of the drill.
