Screw-machine-length drill bit sets, also known as stub-length drill bits, typically include a range of sizes that are shorter than standard jobber-length drill bits. These sets are designed for applications requiring increased rigidity and reduced deflection, making them ideal for precision drilling in metalworking and other demanding tasks.
The sizes in these sets usually cover a comprehensive range to accommodate various drilling needs. Commonly included sizes are:
1. **Fractional Sizes**: These are measured in inches and typically range from 1/16 inch to 1/2 inch, often in increments of 1/64 inch. A standard set might include sizes like 1/16, 3/32, 1/8, 5/32, 3/16, 7/32, 1/4, 9/32, 5/16, 11/32, 3/8, 13/32, 7/16, 15/32, and 1/2 inch.
2. **Numbered Sizes**: These are smaller drill bits, numbered from #1 to #60, with #1 being the largest and #60 the smallest. A typical set might include all or a selection of these sizes.
3. **Letter Sizes**: These range from A to Z, with A being the smallest and Z the largest. A complete set would include all these sizes.
4. **Metric Sizes**: These are measured in millimeters and typically range from 1 mm to 13 mm, often in 0.5 mm increments. A standard metric set might include sizes like 1 mm, 1.5 mm, 2 mm, 2.5 mm, and so on up to 13 mm.
These sets are often available in various configurations, such as fractional-only, numbered-only, letter-only, or a combination of these, depending on the specific requirements of the user.