1/4-20 Thread forming tap |Roll Form Tap for Inch Thread
Key Features of UNC Forming Tap
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Chipless Roll Forming Structure Fluteless design produces zero swarf, completely solving blind hole and deep hole chip blockage problems. Clean threading with no thread scratching.
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Higher Thread Strength Cold extrusion retains continuous metal grain flow. Formed UNC/UNF threads are 20%-30% stronger than cut threads, with better anti-loosening and fatigue resistance.
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Ultra Low Breakage Rate Integrated solid body greatly improves rigidity and torsion resistance. Significantly reduce tap fracture during high-torque continuous tapping.
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High Precision Inch Thread Standard Strictly comply with UNC (Coarse Thread) and UNF (Fine Thread) American standard, standard tolerance 2B, fully interchangeable with US standard fasteners.
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Multiple Coating Options Uncoated / TiN / TiCN / AlTiN / DLC available. DLC for aluminum anti-sticking, AlTiN for stainless steel long-life tapping.
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Longer Tool Life & Lower Cost 2–5 times service life than traditional inch cutting taps, reducing downtime and tool replacement frequency for mass production.
Machinable Materials
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Non-ferrous Metals : Aluminum alloy, brass, copper, zinc die-cast alloy, magnesium alloy
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Carbon Steel : Mild steel, medium carbon steel, low-carbon ductile steel
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Stainless Steel : 201, 304, 316, 316L, 430 stainless steel
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Alloy Steel : 40Cr, SCM435, 42CrMo (≤35HRC tempered alloy steel)
Application Scenarios
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Automotive & Motorcycle Parts Inch thread machining for auto fasteners, hydraulic parts, brake system components and chassis accessories.
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New Energy Industry Precision UNC/UNF threading for battery components, energy storage structural parts and aluminum shell fittings.
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3C & Precision Hardware High-precision inch thread tapping for communication equipment, instrumentation and precision electronic assemblies.
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Mechanical & Mold Manufacturing Blind hole, deep hole and thick plate inch thread processing for molds, fixtures and mechanical equipment.
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Mass Automated CNC Production Stable performance for long-time unmanned machining, ideal for factories pursuing high efficiency and low defective rate.
UNC / UNF Forming Tap Full Specification Table (Standard Dimension)
Standard: ANSI/ASME B1.1 | Tolerance: 2B | Material: HSS-E / HSS-PM Optional
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Thread Size
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Thread Type
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TPI (Threads Per Inch)
|
Overall Length (mm)
|
Shank Diameter (mm)
|
Thread Length (mm)
|
Square Size (mm)
|
|---|---|---|---|---|---|---|
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#4-40
|
UNC
|
40
|
48
|
3.5
|
9
|
2.7
|
|
#6-32
|
UNC
|
32
|
48
|
3.5
|
10
|
2.7
|
|
#8-32
|
UNC
|
32
|
50
|
4.0
|
11
|
3.0
|
|
#10-24
|
UNC
|
24
|
53
|
4.5
|
12
|
3.4
|
|
1/4-20
|
UNC
|
20
|
58
|
6.0
|
14
|
4.9
|
|
5/16-18
|
UNC
|
18
|
66
|
8.0
|
16
|
6.2
|
|
3/8-16
|
UNC
|
16
|
72
|
10.0
|
18
|
8.0
|
Recommended Pre-Drill Size Chart for UNC / UNF Forming Tap
Optimized hole size for roll forming process, ensure standard thread fill rate and low tapping torque
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Thread Size
|
Thread Type
|
TPI
|
Pre-Drill Size (mm)
|
|---|---|---|---|
|
#4-40
|
UNC
|
40
|
2.30
|
|
#6-32
|
UNC
|
32
|
2.85
|
|
#8-32
|
UNC
|
32
|
3.45
|
|
#10-24
|
UNC
|
24
|
4.05
|
|
1/4-20
|
UNC
|
20
|
5.10
|
|
5/16-18
|
UNC
|
18
|
6.60
|
|
3/8-16
|
UNC
|
16
|
8.00
|