Greenfield Threading
Greenfield Threading 280850 Spiral Point Tap Plug 3 Flutes pneumatic accessory
Spiral-point tap cuts 1/2-13 UNC threads in through-holes with three flutes and TiN-coated high-speed steel
- Spiral point design pushes chips forward for smoother threading
- 1/2 inch UNC thread size fits standard coarse-pitch holes
- High-speed steel with TiN coating resists wear during tapping
- Three flutes balance chip clearance and tool strength
- H5 thread limit produces class 2B-3B fit tolerance
1/2 Inch UNC Spiral Point Tap
The Greenfield Threading 280850 is a high-speed steel spiral point tap designed for through-hole threading in unified coarse threads. It suits machinists and maintenance technicians who need reliable thread creation in steel and similar materials.
TiN coating and chip evacuation
The titanium nitride coating reduces friction and extends tool life during repetitive tapping operations. Spiral point geometry pushes chips ahead of the cut, lowering cutting forces and heat buildup in normal use.
Right-hand cut with H5 thread limit
Three flutes provide balanced chip clearance and thread strength for class 2B-3B fit requirements. The 15/16 inch thread length and 0.4219 inch drill size suit standard 1/2-13 UNC applications without special tooling.
Highlights
- Spiral point design pushes chips forward for smoother threading
- 1/2 inch UNC thread size fits standard coarse-pitch holes
- High-speed steel with TiN coating resists wear during tapping
- Three flutes balance chip clearance and tool strength
- H5 thread limit produces class 2B-3B fit tolerance
Specifications
| Brand | CHICAGO-LATROBE |
|---|
Questions about this item
How do I install the 280850 spiral-point tap in a pneumatic tapping head, and what alignment step is often missed?
Clamp the tap squarely in the chuck, use a 0.4219 in drill for the 75 percent thread hole, start the tap perpendicular to the workpiece, and apply steady forward pressure so the spiral point pushes chips ahead without binding.
When will the TiN-coated high-speed-steel flutes need replacement?
Replace the tap when the cutting edges show visible rounding, thread gauges reject the 1/2-13 UNC 2B-3B fit, or chip evacuation slows despite proper lubrication.
What limit appears first during sustained tapping of 1/2-13 UNC holes with this H5-limit tool?
The 15/16 in thread length restricts maximum depth in a single pass; deeper holes require multiple setups or a longer-reach tap.
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