How to Choose the Right Thread Forming Tap
Selecting the correct thread forming tap involves understanding thread standards, workpiece material, hole preparation, and application requirements. This guide covers everything you need to know.
1. Determine Your Thread Standard
Thread forming taps are manufactured to several international standards:
- American UNC/UNF – Used in North America. UNC = Unified National Coarse, UNF = Unified National Fine. Sizes from #6-32 to 1″-16.
- JIS Metric – Japanese Industrial Standard. Common in Asian manufacturing. Sizes from M2x0.4 to M30x1.5.
- DIN Metric – German/European standard. Sizes from M2x0.4 to M20x2.5.
2. Check Workpiece Material
Forming taps work best on materials with good ductility:
| Material | Suitability | Notes |
|---|---|---|
| Aluminum | Excellent | Low forming force, excellent results |
| Mild Steel | Excellent | Standard forming application |
| Copper & Brass | Excellent | Soft, easy to form |
| Stainless Steel | Good | Requires HSSE taps, slower speed |
| Hard Steel (>32 HRC) | Not recommended | Use cutting tap instead |
| Cast Iron | Not recommended | Brittle, may crack during forming |
3. Select the Correct Tap Drill Size
Forming taps require a larger pre-drilled hole than cutting taps because the material is displaced, not removed. The general formula:
Forming tap drill = Major Diameter – (Pitch x 0.5)
Always check the manufacturer’s recommended drill size for your specific tap.
4. Choose the Right Tap Material
- HSSE (High Speed Steel Enhanced) – Best for forming taps. Contains cobalt for heat resistance. Ideal for steel, aluminum, stainless steel. Our forming taps are all HSSE.
- HSS (High Speed Steel) – Standard, shorter tool life than HSSE.
- Carbide – For very hard materials or ultra-high volume. Brittle, more expensive.
5. Consider Speed and Feed
Forming taps run 1.5-2x faster than cutting taps:
- Aluminum: 30-60 m/min
- Mild Steel: 20-35 m/min
- Stainless Steel: 10-20 m/min
Conclusion
Choosing the right forming tap requires matching thread standard, material, drill size, and tap material. For B2B manufacturing, HSSE forming taps offer the best balance of performance, tool life, and cost.
Browse our HSSE forming taps or contact us for custom sizes.