Tap speeds and feeds
Tap feed is always the pitch: one thread per turn. Pick a size for its RPM and feed in each material, a worked example and G84 code. RPM = 3.82 × SFM ÷ tap diameter; IPM = RPM ÷ TPI.
Tapping SFM by material
| Material | Cut tap (general-purpose HSS) | Cut tap (premium, OSG) | Form tap (OSG) |
|---|---|---|---|
| Aluminum 6061 / 7075 | 70–90 | 70–120 | 65–115 |
| Free-machining / mild steel (12L14, 1018) | 20–40 | 80–120 | 50–115 |
| 4140 alloy steel (annealed to <35 HRC) | 20–30 | 35–65 | 50–85 |
| 304 / 316 stainless | 10–20 | 15–75 | 15–40 |
| Tool steel (A2, D2, O1, H13, P20) | 15–25 | 15–30 | 8–25 |
| Gray / ductile cast iron | 15–30 | 50–120 | Not listed |
| Brass / bronze | 60–100 | Not listed | Not listed |
| Titanium (6Al-4V, CP) | 5–15 | 15–20 | 8–15 |
| Plastics and composites (acetal, nylon, G-10) | 50–70 | Not listed | Not listed |
Sources: Productivity Inc. "General Purpose & Other Tap Speeds"; OSG A Brand & Premium Tooling Recommendation Guide Vol. 4 (Threading). Each size page links the documents.
UNC taps
UNF taps
Metric coarse taps
Need the hole first? See the tap drill chart or drill speeds and feeds by size.