Here's the English version of how to choose standard HSS taps based on workpiece material and hole depth:
| Material Type | Recommended Tap Type | Notes |
|---|---|---|
| Soft materials (Aluminum, Brass, Plastic) | Spiral Flute Tap | Smooth chip removal, avoids clogging |
| Carbon Steel, Alloy Steel | Straight Flute / Spiral Flute | General-purpose, spiral flute preferred for blind holes |
| Stainless Steel, Hard Steel | High Helix Spiral Flute (≥35°) | Improves chip evacuation, reduces risk of breakage |
| Cast Iron, Powder Metal | Straight Flute Tap | Brittle chips, no need for aggressive chip evacuation |
| Hole Type | Hole Depth (Relative to Diameter) | Recommended Tap Type | Notes |
|---|---|---|---|
| Through Hole | ≤2×D | Spiral Point Tap (Gun Tap) | Pushes chips forward, ideal for fast tapping |
| Blind Hole | ≤1.5×D | Straight Flute / Spiral Flute | For shallow blind holes, straight flute is sufficient |
| Blind Hole | ≥2×D | Spiral Flute Tap (35°–45° helix) | Effective chip evacuation for deep blind holes |
| Precision Level | Application | Recommended Class |
|---|---|---|
| Standard Fit | General mechanical parts | H2 (2B) |
| Precision Fit | Sealing parts, precision assembly | H3 or tighter |
| Coating | Suitable Materials | Benefit |
|---|---|---|
| TiN | General materials | Increased wear resistance |
| TiAlN | Stainless/Hard steel | High temperature resistance |
| Uncoated | Aluminum, Brass | Reduces built-up edge and sticking |