What Is a Spiral Point Tap and How Does It Work?
A spiral point tap, also known as a gun tap, is a fluted threading tool with a unique angular ground cutting nose. It is mainly manufactured from high-speed steel (HSS-E/PM-HSS) and features straight flutes with a spiral-shaped point geometry. Unlike standard straight taps, its cutting edge is inclined, enabling forward chip pushing. It is exclusively designed for through-hole threading and widely used in automotive, electronics, and general machinery mass production.
Compared with other taps, spiral point taps offer faster cutting speed, lower torque, and cleaner chip removal, making them the first choice for high-volume through-hole projects.
How Does a Spiral Point Tap Work?
The core working principle of a spiral point tap is forward chip evacuation. During tapping, the inclined spiral point cuts the thread profile first and pushes metal chips forward toward the hole exit instead of backward toward the spindle. The straight flutes store and guide continuous chips out of the hole smoothly without tangling or accumulation inside the thread cavity.
Since chips never stay inside the hole, spiral point tapping effectively avoids chip clogging, thread scratching, and tool jamming. This working mechanism also reduces cutting resistance, allowing higher spindle speed and longer tool life in continuous production.
Performance Data Comparison (Spiral Point Tap vs Straight Tap)
Verified by real CNC workshop production (M6 thread, 6061 aluminum):
- Chip Clogging Rate: Spiral point tap 0.4% | Straight tap 4.2%
- Average Tool Life: Spiral point tap 7,800 holes | Straight tap 3,500 holes
- Tapping Torque: 18% lower than standard straight taps
- Qualified Thread Rate: 99.6% vs 95.8%
The data clearly proves that the spiral point tap’s forward chip removal mechanism significantly improves production stability.
Real Workshop Application Example
A precision electronics manufacturer produces 30,000 aluminum connector parts monthly with M4 through-hole threads. Previously, the factory used standard straight flute taps, suffering frequent chip jamming, scratched threads, and a 3.8% scrap rate.
After switching to TiN-coated spiral point taps, forward chip ejection completely eliminated internal chip accumulation. The scrap rate dropped to 0.3%, tool change frequency decreased by 55%, and tapping cycle efficiency increased by 22%. The factory achieved stable high-speed mass production with zero thread burrs and consistent 6H thread tolerance.
Key Advantages & Limitations
Advantages: Forward chip removal prevents hole contamination; lower torque reduces tap breakage; supports high-speed tapping; ideal for soft and medium-hard materials including aluminum, brass, and mild steel.
Limitations: The biggest restriction is unsuitable for blind holes. Forward chip ejection will trap chips at the blind hole bottom, causing tool breakage and incomplete threads. For blind holes, spiral flute taps are the correct option.
Best Usage Scenarios
Spiral point taps work best for through-hole threading, shallow to medium-depth holes (1–3×D), and high-volume batch production. They are widely applied in 6061 aluminum, brass, copper, and low-carbon steel threading projects across electronic hardware, automotive brackets, and mechanical fastener components.
A spiral point tap is a high-efficiency through-hole threading tool that works by forward chip ejection to deliver cleaner threads, lower torque, and longer tool life. It is irreplaceable for mass through-hole production, though it must never be used for blind holes. Understanding its working principle helps CNC manufacturers select the right tap, reduce scrap, and optimize production efficiency.
Looking for durable spiral point taps for mass production? Contact our team for customized technical parameters, free samples, and factory wholesale pricing.