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HSS Spiral Point Taps for Through Holes Metric, JIS & UNC

HSS-E spiral point taps (gun taps) feature a specialized angled cutting face at the tip that aggressively pushes chips forward and out through the bottom of the hole. This forward chip evacuation makes them the ultimate choice for high-speed CNC rigid tapping of through holes. Manufactured from premium HSS-E (Cobalt) with TiN coating, they prevent chip recutting, eliminate hole jamming, and allow for significantly higher cutting speeds in steel, stainless steel, and aluminum. Available in Metric/JIS, American UNC, and Long Shank series for deep cavity reach.

Procurement Terms
MOQ 50 pcs per size for standard metric/UNC; 20 pcs per size for long shank specials
Lead Time 3–7 days for stock sizes; 15–20 days for custom thread limits or special shanks
Inventory Standard M1–M20, UNC series, and 100mm Long Shank maintained in stock
Material Grades HSS-E (High-Speed Steel with Cobalt)
Finish / Coating TiN (Titanium Nitride) for enhanced hardness and wear resistance
Packaging Individual plastic tubes, blister cards, or OEM branded boxes
Shipping DHL / FedEx / UPS for air orders; sea freight for bulk distributor programs
Payment T/T, PayPal, Western Union; L/C for large volume orders
Sample Policy Paid samples available; cost refundable on first bulk order

Technical Specifications
Tap Type Spiral Point (Gun Tap)
Hole Application Through Holes (Forward Chip Evacuation)
Point Geometry Angled cutting face to push chips downward
Thread Standards Metric (JIS Coarse Pitch), UNC (Unified)
Thread Tolerance ISO2 (6H) / JIS Class 2 / UNC Class 2B
Shank Type Standard Cylindrical / Long Shank (100mm OAL)
Material Substrate HSS-E (Cobalt enriched for heat resistance)
Surface Treatment TiN (Titanium Nitride) PVD Coating
Core Engineering Advantages
Forward Chip Evacuation: Pushes chips ahead of the tap and out the bottom, eliminating chip packing and recutting inside the hole.
Higher Cutting Speeds: Reduced friction and heat generation allow for 20–30% higher Vc in CNC rigid tapping compared to standard hand taps.
TiN Coating Durability: Enhances surface hardness to HRC 80+, ensuring reliable performance in both dry and wet cutting conditions.
Through-Coolant Ready: Optimized flute geometry works perfectly with high-pressure through-spindle coolant for deep through-hole applications.

Cutting Data / Application Guide
Optimized Cutting Parameters for Through Holes
ISO Material Workpiece Material Cutting Speed (Vc)
m/min Tap Drill Depth Rule Coolant Requirement
P Carbon Steel, Alloy Steel 15 – 35 Through Hole + 2 Pitches clearance Emulsion (10-15% concentration)
M Stainless Steel (304, 316) 10 – 18 Through Hole + 3 Pitches clearance Heavy-duty cutting oil / MQL
K Cast Iron (Grey, Nodular) 20 – 40 Through Hole + 2 Pitches clearance Dry or Air Blast
N Aluminum & Alloys 30 – 60 Through Hole + 3 Pitches clearance Light emulsion or Air Mist
Critical Through Hole Tapping Guidelines
Clearance Hole: Ensure the drilled hole extends at least 2–3 thread pitches beyond the required thread depth to allow chips to exit freely without jamming against the bottom of the hole.
Rigid Tapping Sync: Spiral point taps excel in CNC rigid tapping (G84). Ensure precise spindle/Z-axis synchronization to prevent thread tearing at the rapid reversal point.
Chip Flow Direction: Never use a spiral point tap in a blind hole or a hole with a stepped bottom that blocks the forward exit path of the chips.

Why Choose Spiral Point Taps

Precision Gun Point Geometry
Our CNC-ground spiral point angles are mathematically optimized to curl and push chips cleanly forward, eliminating the risk of chip recutting and thread galling in high-speed production.

Rigid Tapping Optimized
Designed specifically for modern CNC machining centers, our gun taps withstand the high axial forces of rigid tapping cycles while maintaining strict ISO2 (6H) pitch diameter tolerances.

Anti-Wear TiN Coatings
Advanced TiN PVD coatings reduce friction at the cutting edge, allowing for 20–30% higher cutting speeds and significantly extending tool life in abrasive alloy steels.

Real-World Performance
Automotive Engine Manufacturing
Cast Iron Engine Block Through Holes
Workpiece: GG25 Grey Cast Iron engine block, M10 × 1.5 through holes

Machine: High-speed horizontal CNC machining center, dry air blast

Result: Amony HSS-E TiN spiral point taps achieved 8,000 holes per tool with zero chip jamming

Forward chip evacuation eliminated the need for secondary hole cleaning operations

Aerospace Structural Components
6061-T6 Aluminum Wing Rib Threading
Workpiece: 6061-T6 Aluminum alloy, 1/2″-13 UNC through holes

Machine: 5-axis CNC mill, high-pressure through-spindle coolant

Result: gun taps ran at 60 m/min (2x standard speed) without built-up edge (BUE)

Cycle time reduced by 15% per part due to aggressive cutting parameters enabled by the gun point geometry

Spiral Point Tap Series & Size Chart

Select a series below to view the standard specifications. Custom pitches and tolerances available on request.

Thread Size Pitch (mm) Overall Length (mm) Thread Length (mm) Neck Length (mm) Shank Dia. (mm)
M1.0 0.25 32 5.5 15 3.0
M1.2 0.25 32 5.5 15 3.0
M1.4 0.3 36 8.0 15 3.0
M1.6 0.35 36 8.0 15 3.0
M1.7 0.35 36 8.0 15 3.0
M1.8 0.35 36 8.0 15 3.0
M2.0 0.4 42 9.5 15 3.0
M2.5 0.45 44 9.5 16 3.0
M3.0 0.5 46 11.0 18 4.0
M4.0 0.7 52 13.0 20 5.0

Thread Size Overall Length (mm) Thread Length (mm) Shank Dia. (mm) Square Size (mm)
2-56 UNC 42 9.5 3.0 2.5
4-40 UNC 44 9.5 3.0 2.5
6-32 UNC 48 13.0 4.0 3.2
8-32 UNC 52 13.0 5.0 4.0
10-24 UNC 60 16.0 5.5 4.5
1/4-20 UNC 60 19.0 6.0 4.5
5/16-18 UNC 70 22.0 6.1 5.0
3/8-16 UNC 75 24.0 7.0 5.5
1/2-36 UNC 85 29.0 9.0 7.0

Thread Size Pitch (mm) Overall Length (mm) Thread Length (mm) Shank Dia. (mm) Square Size (mm)
M2.0 0.4 100 9.5 3.0 2.5
M2.5 0.45 100 9.5 3.0 2.5
M3.0 0.5 100 11.0 4.0 3.2
M4.0 0.7 100 13.0 5.0 4.0
M5.0 0.8 100 16.0 5.5 4.5
M6.0 1.0 100 19.0 6.0 4.5
M8.0 1.25 100 22.0 6.2 5.0
M10.0 1.5 100 24.0 7.0 5.5