Taps and dies are often used in metalworking to cut threads onto or into metal components. Taps are used to cut a female thread into a pre drilled hole which must be smaller then the tap for the thread to be cut correctly. Dies are used to cut a male thread onto round bar, it is essential that the correct sized bar is used for the appropriate die or else damage can be caused to the die.
This is a cheap tap and die set, this set will be ok for occasional use but in a commercial environment it will not last five minutes. There is a huge difference in price between cheap high carbon steel cutting tools and expensive ones made from high speed steel.
If you intend tapping or threading on a regular basis it would be well worth spending the extra money to buy quality taps and dies.
This is a set of taps made by Roebuck, the set includes a taper tap, intermediate tap and a plug tap. A set like this should last for years as long as they are used correctly.
This is a selection of dies. The thread size and pitch is marked on the front of each die.
This is part of a low quality set and should be ok for occasional use.
Dies are normally used with a die stock, this picture shows the die stock with the die already inserted.
Taps are normally used with a tap wrench, there are a few different kinds of tap wrench but they all do the same thing. In tight corners you can even use the correct sized spanner to turn the tap.
Metric ISO coarse thread drill tapping sizes
| Thread diameter (MM) | Pitch (mm) | Tapping drill diameter (MM) |
| M1.6 | 0.35 | 1.25 |
| M2.0 | 0.40 | 1.60 |
| M2.2 | 0.45 | 1.75 |
| M2.5 | 0.45 | 2.05 |
| M3.0 | 0.50 | 2.50 |
| M3.5 | 0.60 | 2.90 |
| M4.0 | 0.70 | 3.30 |
| M4.5 | 0.75 | 3.70 |
| M5.0 | 0.80 | 4.20 |
| M6.0 | 1.00 | 5.00 |
| M7.0 | 1.00 | 6.00 |
| M8.0 | 1.25 | 6.80 |
| M9.0 | 1.25 | 7.80 |
| M10.0 | 1.50 | 8.50 |
| M11.0 | 1.50 | 9.50 |
| M12.0 | 1.75 | 10.20 |
| M14.0 | 2.00 | 12.00 |
| M16.0 | 2.00 | 14.00 |
| M18.0 | 2.50 | 15.50 |
| M20.0 | 2.50 | 17.50 |
| M22.0 | 2.50 | 19.50 |
| M24.0 | 3.00 | 21.00 |
| M27.0 | 3.00 | 24.00 |
| M30.0 | 3.50 | 26.50 |
| M33.0 | 3.50 | 29.50 |
| M36.0 | 4.00 | 32.00 |
For instructions on how to use a tap please look here-
Tapping metal (video)
Drill tapping (video)
Tap Acrylic (video)
