What Is a Tapped Hole?
A tapped hole is a hole that has internal threads created using a tap or another threading tool.
For example, an M6 tapped hole is designed to accept an M6 screw or bolt. During CNC machining, the hole is first drilled to the appropriate tap-drill diameter and then the internal thread is produced.
Tapped holes are commonly used for:
- Mounting components
- Fastening covers and brackets
- Assembly of mechanical parts
- Connecting parts without using nuts
What Is a Threaded Hole?
A threaded hole is a more general term for any hole containing internal threads. The threads can be produced by tapping, thread milling, or other machining methods.
Therefore, a tapped hole is a type of threaded hole, but not every threaded hole is necessarily made by traditional tapping.
Tapped vs Threaded
| Feature | Tapped Hole | Threaded Hole |
|---|---|---|
| Meaning | Internal thread made by tapping | General term for an internally threaded hole |
| Typical process | Tap | Tapping or thread milling |
| Common use | Screws and bolts | Screws, bolts, and mechanical connections |
| Drawing example | M4 × 0.7 TAP | M4 × 0.7 internal thread |
What Should Be Specified on a CNC Drawing?
When ordering CNC machined parts, it is important to provide clear thread information. A drawing may specify the thread size, pitch, depth, tolerance, and thread standard.
For example:
M6 × 1.0 – 10 mm deep
This indicates an M6 metric thread with a 1.0 mm pitch and a specified thread depth of 10 mm.
For blind holes, the usable thread depth should also be distinguished from the total drilled-hole depth.
At Jingcheng, we machine tapped and threaded holes for prototypes and low-volume CNC production. Send us your 2D drawing or 3D model, and our engineering team can review the thread requirements before production.
