Tapping

Tapping creates internal threads in a hole to allow attachment of threaded fasteners. While the principle is simple, achieving a reliable joint in sheet metal or technical plastics requires following several criteria: choice of thread type, engagement depth, minimum distances between holes, and matching material thickness to thread depth. Holes are machined at the same time as the profile, either by laser or CNC router, and threads are made in a subsequent step. Our application automatically filters available thread sizes according to material, thickness and required clearances relative to other elements.

Thread Engagement

Thread engagement represents the percentage of screw threads that properly mesh with the tapped hole threads. To ensure required mechanical strength, tension and shear factors must be considered according to application. Adequate engagement ensures forces are distributed evenly across multiple threads, avoiding stress concentration.

Thread Pitch and Standards

Thread pitch indicates the number of threads in a given space. We support three systems:

  • SAE: Format ½-20 (½" diameter, 20 threads/inch)
  • Metric: Format M10-1.5 (10 mm diameter, 1.5 mm between threads)
  • ANSI: Format 10-32 (standardized size 10, 32 threads/inch)

Coarse vs Fine Thread

Coarse threads have a wider pitch (fewer threads per inch), while fine threads have a reduced pitch (more threads). Coarse threads are more common and more resistant to stripping. Fine threads offer a more precise fit but require greater engagement depth and are more sensitive to galling during high-speed tightening.

For thin sheets or when direct tapping is impractical, use a self-clinching nut or other type of insert from the hardware section. Tapped parts may have a slight cutting oil film around holes. All threads are right-hand, made perpendicular, through full thickness.

Tapping process

Compatible Materials

Discover materials supporting tapping in our production flow.

Technical Specifications

What you need to know about tapping

  • Automatic selection of tap sizes according to material, thickness and required clearances.
  • Guarantees at least 2 complete threads of engagement.
  • All threads are right-hand, made perpendicular, through full thickness.
  • Minimum hole-to-hole and hole-to-edge distances required according to material.
  • A slight cutting oil film may be present around tapped holes.
  • For thin sheets, prefer a self-clinching nut or hardware insert.

Available Thread Dimensions

Tap sizes with corresponding drill hole diameters. Holes are automatically resized by our application to match the selected tap.

Thread Hole (in) Hole (mm)
4-40 0.091" 2.32
6-32 0.116" 3.00
8-32 0.138" 3.51
10-32 0.164" 4.17
1/4-20 0.209" 5.31
1/4-28 0.221" 5.62
5/16-18 0.266" 6.76
5/16-24 0.278" 7.07
3/8-16 0.323" 8.21
3/8-24 0.341" 8.67
1/2-13 0.435" 11.05
1/2-20 0.459" 11.66
M2 × 0.4 0.065" 1.66
M2.5 × 0.45 0.083" 2.11
M3 × 0.5 0.102" 2.60
M4 × 0.7 0.134" 3.41
M5 × 0.8 0.170" 4.32
M6 × 1.0 0.203" 5.16
M8 × 1.25 0.274" 6.96
M10 × 1.5 0.344" 8.74

Note: Hole diameters are optimized for our tapping service. For manual tapping, consult the manufacturer's tap charts you are using.