A drill grinder is a specialized machine tool designed for sharpening dull or worn drill bits, restoring their cutting edges to optimal geometry for efficient and precise drilling operations.
Key Benefits of Using a Drill Grinder
- Extended Drill Bit Life: Properly regrinding bits significantly prolongs their usability, reducing the frequency of purchasing new ones.
- Improved Drilling Performance: Sharp bits cut faster, cleaner, and more accurately, reducing wander and improving hole quality.
- Cost Savings: Lower expenditure on new drill bits and reduced production downtime contribute to overall cost efficiency.
- Consistent Geometry: Ensures correct point angle, chisel edge, and relief angle, which are crucial for optimal cutting action and chip evacuation.
Common Types and Features
Drill grinders vary in complexity and capability:
- Manual Grinders: Require operator skill to set angles and feed the drill bit. Suitable for occasional use or smaller shops.
- Semi-Automatic/Automatic Grinders: Offer more precise control and automation in the grinding process, often with preset angles and automated feed. Some models are CNC controlled for high precision and repeatability.
- Capacity: Grinders are specified by the range of drill bit diameters they can accommodate (e.g., 2mm to 13mm, or larger industrial sizes).
- Grinding Wheels: Typically use Borazon (CBN) wheels for HSS (High-Speed Steel) bits or diamond wheels for carbide bits.
- Adjustable Angles: Critical features include the ability to adjust the point angle (e.g., 90° to 140°), relief angle, and sometimes chisel edge angle.
Operational Considerations
Effective use of a drill grinder involves:
- Proper Setup: Accurately aligning the drill bit according to the machine's instructions.
- Correct Wheel Selection: Using the appropriate grinding wheel material for the drill bit material.
- Understanding Drill Geometry: Knowledge of point angles, relief angles, and web thinning is beneficial for achieving optimal results.
- Safety: Adhering to safety guidelines, including the use of eye protection and machine guards.
Drill grinders are indispensable tools in machine shops, manufacturing facilities, and any environment where drilling is a frequent operation, helping to maintain tool sharpness, improve hole quality, and optimize operational efficiency.
