Thread milling and thread tapping are two distinct machining processes used to cut threads into a component. While both methods achieve similar end results, they differ significantly in their approach, advantages, and applications.
Check out our article on thread cutting vs thread rolling
What is Thread Tapping?
Thread tapping is the more traditional method of creating threads using a cutting tool called a tap. A tap matches the desired thread size and pitch and typically looks like a standard drill bit with the desired screw thread grooves.
Thread tapping is a fairly straightforward process that can be applied either by hand or with CNC machining. Firstly a tapping hole, a hole that is just the right size to fit the tap but small enough to leave enough material for the thread, is drilled into the component. After drilling, the tap can be lined up with the tapping hole and turned into the hole, cutting the thread as the tap lowers.
Advantages of Thread Tapping
- Faster cycle times for single holes
- Simple programming requirements
- Lower initial tooling costs
- Works well in blind holes
Limitations of Thread Tapping
- Higher risk of tap breakage
- Better suited for smaller diameter holes
- Cannot tap external threads
- Limited to one thread size per tool. If you need to make different thread sizes, you will need one tool per thread type.
- Can struggle with harder materials
What is Thread Milling?
Unlike thread tapping which is limited to one tool per thread type, thread milling uses a specialised cutting tool called a thread mill. The thread mill, typically used with CNC machining for precise control, rotates and moves in a helical path to create the desired thread.
Advantages of Thread Milling
- Lower risk of tool breakage
- One tool can cut multiple thread sizes
- Superior thread quality
- Better for harder materials
Limitations of Thread Milling
- Longer cycle times
- Higher initial investment in tooling
- Requires more specialised machinery
- More complex programming needed
Choosing Between the Two Methods
The choice between thread tapping and thread milling and depends on several factors:
- Material hardness and type
- Thread size and quality requirements
- Production volume
- Available machinery capabilities
- Cost
| The Need… | Thread Tapping | Thread Milling |
|---|---|---|
| Material Type | Softer materials | All material types |
| Production Type | High volume production (of common thread sizes) | Lower volume production |
| Quality | Good thread fit and quality | Higher accuracy in thread fit and quality |
| Hole Size | Smaller diameter holes | Larger diameter holes |
| Machine Capabilities | Simple machining operations (by hand capabilities) | More complex machining operations |
| Cost | Cheaper set up costs | Cheaper long term costs |
Both thread tapping and thread milling have their place in modern manufacturing.
In simple terms: use thread tapping for making lots of small, common-sized threaded holes in softer materials. Choose thread milling when you need more precise threads, larger holes, or when working with harder materials.
Leave a Reply
You must be logged in to post a comment.