twist drill
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Definition
Noun: A twist drill is a cutting tool used for making cylindrical holes. It is characterized by having deep helical grooves (called flutes) along its body. These grooves serve to remove cut material (chips) from the hole and to allow cutting fluid to reach the cutting edges.
Usage
The term "twist drill" is used to specify this common type of drill bit, distinguishing it from other types like spade bits, hole saws, or masonry bits. - It is typically used with hand drills (drill drivers) or drill presses. - It is primarily designed for drilling into metal, wood, and plastic.
Examples
Advanced Usage
- Technical Specification: In machining, the geometry of a twist drill (point angle, helix angle, flute length) is specified based on the material being drilled.
- Dulling/Sharpening: A common phrase is "to sharpen a twist drill," referring to the process of re-grinding its cutting edges on a specialized grinder or fixture.
Variants and Related Words
- Drill bit: A more general term for any cutting tool used to create holes. A twist drill is a type of drill bit.
- Bit: A common short form for "drill bit" in many contexts (e.g., "a drill and a set of bits").
- Flute: Refers specifically to the helical groove on the body of the twist drill.
- Jobber-length drill: A standard-length twist drill, the most common type found in general-purpose sets.
Synonyms
- Spiral drill (less common but descriptive synonym).
- Helical drill (technical synonym emphasizing the helical groove shape).
Related Phrases
- Twist drill point: Refers specifically to the conical cutting tip at the end of the drill.
- Twist drill set: A collection of twist drills of various diameters.
Noun
- a bit or drill having deep helical grooves