BAER HSS Machine Tap - Form C - UNEF 7/8 x 20 - ISO 529
BAER HSS Machine Tap - Form C - UNEF 7/8 x 20 - ISO 529
Our machine taps are powerful and reliable taps for efficient machining in one step with the machine. Machine taps are used especially in industrial manufacturing. They can be used in CNC machines, thread cutting machines, cordless drills and pneumatic tapping arms, among others. As they are characterised by high efficiency and low production costs, they are often used in series production. The thread is cut by machine in one operation. Thus, although the BAER machine tap can basically be compared to short machine tap, it is designed for use with the machine.
The machine tap can be used for through holes and for blind holes, as the short chamfer-in and the straight flutes ensure that the chip remains in the flutes and is not transported away.
Every material shows individual chip behaviour. Therefore, screw taps must have the correct rake angle and - for even better results - a specially treated surface. Only in this way does a good chip transport take place and a thread containing gauges is produced.
The high quality of the ground HSS high-speed steel we use ensures that our tools are extremely durable and robust. Due to special hardening processes and repeated tempering the hardness structure is very homogeneous, which forms the ideal basis for a genuine BAER screw taps. This increases the toughness and stability of the screw taps, allowing them to remain in use for longer.
Dimensions
| Diameter |
7/8 |
|---|---|
| Nominal diameter in inches |
0,875 |
| Nominal diameter in mm |
22,225 |
| Pitch |
20 |
| Pitch in mm |
1,27 |
| Dimension |
UNEF 7/8 x 20 |
Characteristics
| Product group |
Screw taps |
|---|---|
| Product type |
Machine taps |
| Thread standard |
UNEF: American Extra Fine Unified National thread according to ANSI B1.1 |
| Tolerance |
2B |
| Direction |
Right |
| Standard |
ISO 529 |
| Tensile strength at room temperature |
up to 900 N/mm² | 27.1 HRC |
| Material |
HSSG bright |
21 mm
Through hole and blind hole up to 2 x D
Form C straight fluted
2-3 threads
Rarely occurs. Chips remain in flutes.
External cooling and lubrication
HSSG bright
up to 900 N/mm² | 27.1 HRC
2B
Applications
- Materials with good machinability up to 900 N/mm²
- Unalloyed and low-alloy steels
Technical drawing
| D1 |
UNEF 7/8 x 20 |
|---|---|
| D2 |
16 mm |
| L1 |
118 mm |
| L2 |
38 mm |
| Diameter |
7/8 |
| Square |
12,5 mm |
Application – Sample materials for taps
| Unalloyed construction steels | Cutting speed vc in m/min | |
|---|---|---|
| 1.0037 | St 37-2 | 5 - 12 |
| 1.0044 | St 44-2 | 5 - 12 |
| 1.0039 | S 235JRG1+CR | 5 - 12 |
| 1.0060 | St 60-2 | 5 - 10 |
| Free-cutting steels | Cutting speed vc in m/min | |
|---|---|---|
| 1.0718 | 9 SMnPb 28 | 5 - 12 |
| 1.0721 | 10 S 20 | 5 - 12 |
| 1.0736 | 9 SMn 36 | 5 - 12 |
| 1.0726 | 35 S 20 | 5 - 10 |
| Cast steel | Cutting speed vc in m/min | |
|---|---|---|
| 1.0420 | GS-38 | 8 - 15 |
| 1.1120 | GS-20 Mn 5 | 5 - 15 |
| 1.5633 | GS-24 Ni 8 | 5 - 12 |
| 1.7379 | GS-18 CrMo 9 10 | 5 - 12 |
| Alloyed construction steels | Cutting speed vc in m/min | |
|---|---|---|
| 1.5415 | 15 Mo 3 | 5 - 12 |
| 1.5622 | 14 Ni 6 | 5 - 10 |
| 1.7335 | 13 CrMo 4 4 | 5 - 10 |
| 1.7715 | 14 MoV 6 3 | 5 - 10 |
Cutting speed vc [m/min] = (Outer diameter * π * speed) / 1000
Rotation speed n [1/min] = (Cutting speed in m/min * 1000) / (Outer diameter * π)
Feedrate programming [mm/min] = speed * pitch
Please note that the above cutting speeds are indicative and must be adjusted depending on lubrication and actuation.
Further information
- UNEF - Unified National Extra Fine Thread Series ANSI B1.1 American extra fine thread
- Designations, geometries and definitions on taps
- Thread tolerances of the internal thread
- Internal thread and core hole dimensions
- Tap Chamfer forms
- Comparison inch-mm
- Surface treatments on tapping tools
- Cutting speeds and lubrication/cooling
- Information about tapping
- Material table
