

HSS-E Oversize Spiral Point Tap American OS-POT
The OS-POT is an oversize tap made of cobalt high-speed steel (HSS-E) — oversized thread to allow for plating thickness or to compensate for material shrinkage after tapping. It comes in 20 sizes across UNC and UNF (thread dia #4~#10).
Specifications (20 items)
| Part No. | Standard | Dia. | Oversize |
|---|---|---|---|
| ANBWCOS-POT-UNC_4+3 | UNC | #4 | 0.03 |
| ANBWCOS-POT-UNC_4+5 | UNC | #4 | 0.05 |
| ANBWCOS-POT-UNC_4+7 | UNC | #4 | 0.07 |
| ANBWCOS-POT-UNC_4+10 | UNC | #4 | 0.1 |
| ANBWCOS-POT-UNC_6+3 | UNC | #6 | 0.03 |
| ANBWCOS-POT-UNC_6+5 | UNC | #6 | 0.05 |
| ANBWCOS-POT-UNC_6+7 | UNC | #6 | 0.07 |
| ANBWCOS-POT-UNC_6+10 | UNC | #6 | 0.1 |
| ANBWCOS-POT-UNC_8+3 | UNC | #8 | 0.03 |
| ANBWCOS-POT-UNC_8+5 | UNC | #8 | 0.05 |
| ANBWCOS-POT-UNC_8+7 | UNC | #8 | 0.07 |
| ANBWCOS-POT-UNC_8+10 | UNC | #8 | 0.1 |
| ANBWCOS-POT-UNC_10+3 | UNC | #10 | 0.03 |
| ANBWCOS-POT-UNC_10+5 | UNC | #10 | 0.05 |
| ANBWCOS-POT-UNC_10+7 | UNC | #10 | 0.07 |
| ANBWCOS-POT-UNC_10+10 | UNC | #10 | 0.1 |
| ANBWCOS-POT-UNF_10+3 | UNF | #10 | 0.03 |
| ANBWCOS-POT-UNF_10+5 | UNF | #10 | 0.05 |
| ANBWCOS-POT-UNF_10+7 | UNF | #10 | 0.07 |
| ANBWCOS-POT-UNF_10+10 | UNF | #10 | 0.1 |
Specification Range
| Diameter | #4~#10 |
|---|
Product Description
The OS-POT is an oversize tap made of cobalt high-speed steel (HSS-E) — oversized thread to allow for plating thickness or to compensate for material shrinkage after tapping. It comes in 20 sizes across UNC and UNF (thread dia #4~#10). Supplied uncoated (bright finish). It handles carbon and alloy steel, stainless steel, cast iron, non-ferrous metals such as aluminium and copper, with workpiece hardness up to HRC40. Typical applications: Unified (UN) through-hole tapping before plating or zinc coating; the thread is cut slightly oversize to allow for the coating thickness, so the screw still fits after finishing. This is the spiral point version, pushing chips ahead. In the same H.T.D family: the oversize spiral flute OS-SFT (for blind holes, also 20 sizes), the metric OS-POT-M and the Whitworth OS-POT-W; this series covers UNC #4~#10 and UNF #10, every size in four oversize grades: 0.03, 0.05, 0.07 and 0.1mm. #10 comes in both UNC and UNF; which one? Follow the thread on the drawing; choose the oversize by coating thickness, four grades from 0.03 to 0.1mm. Can it tap blind holes? For blind holes use the oversize spiral flute OS-SFT.
Workpiece Materials & Hardness
- Steel (P)
- Stainless steel (M)
- Cast iron (K)
- Non-ferrous metals (N)
Max. workpiece hardness HRC40
Related Resources
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