Cutting External Metric Threads - Instructions
An external thread can be produced quickly in just a few steps with the right tool. You should know that external threads are always cut on a round bolt or rod, the
bolt diameter must be slightly smaller than the thread you want to cut. In the table below you can see for which thread you need which bolt diameter.
The following tools are required for external thread cutting:
- Tap set (buy here cheap)
- Cutting oil (buy here cheap)
You will find the suitable bolt diameter for the respective thread in the following chart.
Cutting External Threads Chart
|
Thread Sizes |
Bolt Diameter (mm) |
Mertric Thread Pitch (mm) |
| M1 | 0,97 | 0,25 |
| M1,1 | 1,07 | 0,25 |
| M1,2 | 1,17 | 0,25 |
| M1,4 | 1,36 | 0,30 |
| M1,6 | 1,54 | 0,35 |
| M1,8 | 1,74 | 0,35 |
| M2 | 1,94 | 0,40 |
| M2,2 | 2,13 | 0,45 |
| M2,5 | 2,43 | 0,45 |
| M3 | 2,92 | 0,50 |
| M3,5 | 3,41 | 0,60 |
| M4 | 3,91 | 0,70 |
| M5 | 4,90 | 0,80 |
| M6 | 5,88 | 1,00 |
| M7 | 6,88 | 1,00 |
| M8 | 7,87 | 1,25 |
| M9 | 8,87 | 1,25 |
| M10 | 9,85 | 1,50 |
| M12 | 11,83 | 1,75 |
| M14 | 13,82 | 2,00 |
| M16 | 15,82 | 2,00 |
| M18 | 17,79 | 2,50 |
| M20 | 19,79 | 2,50 |
| M22 | 21,79 | 2,50 |
| M24 | 23,77 | 3,00 |
| M27 | 26,77 | 3,00 |
| M30 | 29,73 | 3,50 |
| M36 | 35,70 | 4,00 |
| M42 | 41,69 | 4,50 |
| M48 | 47,66 | 5,00 |
| M56 | 55,62 | 5,50 |
| M64 | 63,58 | 6,00 |
* All information without guarantee.
Cutting External Threads - step by step instructions
1. Determine the pin diameter with a caliper gauge.
2. A tropical cutting oil on the tap and on the bolt.
3. Then turn the tap one turn clockwise.
Attention! Always place the die straight and not at an angle!
4. Then turn the tap counterclockwise for half a turn.
This is very important in order to break off the chip that occurs during cutting.
5. Repeat the cutting process as described in points 3. and 4. until the desired thread length has been reached.
The function of the finished thread can then be checked with a suitable nut.
If you want to know how to cut an internal thread yourself in just a few steps, you will find all the information here.
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