Product

Metric spiral flute tap

metric spiral flute tap

Key Features

  • Upward Spiral Flute Design: Optimized spiral angle ensures smooth upward chip removal, perfect for blind hole threading, no chip accumulation at the hole bottom.
  • Premium Raw Material: Adopts high-quality HSS or HSS-E cobalt high-speed steel, excellent hardness, toughness and heat resistance, resistant to breakage during continuous tapping.
  • Multiple Functional Coatings Optional: Oxide, TiN, TiCN, TiAlN and stainless steel special anti-stick coatings, meeting different material processing needs.
  • Fully Precision Ground: Integral grinding process ensures sharp cutting edge, low tapping torque, burr-free and high-precision 6H standard threads.
  • High Compatibility: Standard metric thread sizes, compliant with DIN371 / DIN376 / ISO standards, suitable for most CNC machines and automatic lathes.

Technical Specifications

Item

Specification

Product Name

Metric Spiral Flute Machine Tap

Thread Standard

Metric ISO Standard (Coarse / Fine Pitch)

Material

HSS M2 / HSS-E M35 Cobalt High Speed Steel

Available Coatings

Black Oxide, TiN (Gold), TiCN (Rainbow), TiAlN, SUS Special Coating

Flute Type

Right-hand Spiral Flute (for blind hole)

Helix Angle

35° Standard (optimized for chip removal)

Thread Tolerance

6H (Standard)

Hardness

HRC 63–67

Applicable Hole

Blind Hole

Size Range

M2–M20 (Custom sizes available)

Applicable Materials & Application Scenarios

Processable Materials:

  • ✅ Mild steel, medium carbon steel, high carbon steel
  • ✅ Alloy steel, pre-hardened steel
  • ✅ Cast iron, ductile iron
  • ✅ SUS303, 304, 316 stainless steel (with special coating)
  • ✅ Brass, copper and other non-ferrous metals

Application Scenarios: CNC machining centers, automatic lathes, mechanical parts processing, automotive parts, hydraulic components, electronic hardware and general industrial mass production.

Standard Tap Drill Size Chart (Metric Coarse Thread / 75% Thread Engagement)

Recommended bottom hole diameter for standard carbon steel processing; enlarge 5%–10% for stainless steel to avoid tap breakage.

Thread Size

Pitch

Standard Drill Size (mm)

M2

0.4

1.6

M2.5

0.45

2.05

M3

0.5

2.5

M4

0.7

3.3

M5

0.8

4.2

M6

1.0

5.0

M8

1.25

6.8

M10

1.5

8.5

M12

1.75

10.2

M14

2.0

12.0

M16

2.0

14.0

M18

2.5

15.5

M20

2.5

17.5

Processing Tips

  • For carbon steel: Use TiN / Oxide coating, standard speed and standard bottom hole size.
  • For stainless steel: Choose TiCN / SUS anti-stick coating, reduce speed to 50%–70%, enlarge bottom hole and use extreme pressure tapping oil.
  • For hardened steel: Adopt TiAlN coating for high temperature resistance and wear resistance.