Power Saw & Drill Press Operations
Bandsaw blade selection, cutting thin-walled materials, drill point angles, peck drilling, and spot drilling techniques.
- Select appropriate bandsaw blades based on material and tooth pitch
- Describe drill point geometry and standard drill angles
- Explain peck drilling, spot drilling, and web thinning techniques
Leçon 1
Bandsaw Blade Selection & Operations
Blade Tooth Pitch
Tooth pitch (teeth per inch or TPI) is the most important factor in bandsaw blade selection. The rule is: at least 3 teeth must be in contact with the workpiece at all times. Fewer than 3 teeth causes the blade to straddle the work and snag, breaking teeth or stalling the cut.
Cutting Thin-Walled Materials
When cutting thin-walled tubing or sheet metal, use a fine-pitch blade (higher TPI) to maintain 3 teeth in contact. Clamp the workpiece securely to prevent vibration. Reduce cutting speed and feed pressure to avoid blade grabbing.
Blade Types
| Blade Type | Teeth Pattern | Best For |
|---|---|---|
| Regular tooth | Evenly spaced, 0-degree rake | General purpose, soft metals |
| Skip tooth | Every other tooth removed | Soft materials, deep cuts |
| Hook tooth | Positive rake angle | Aggressive cuts in thick stock |
| Variable pitch | Alternating TPI | Reduces vibration, structural shapes |
Exam Tip - Thin Wall Rule
If the exam asks about cutting thin tubing on a bandsaw, the answer involves selecting a finer pitch (higher TPI) blade to keep at least 3 teeth in contact with the wall thickness.
At least 3 teeth must be in contact with the workpiece at all times. Use fine pitch (high TPI) for thin materials and coarse pitch (low TPI) for thick solid stock.