BAER HSSE Machine Tap - 35° RSP - UNF 1/4 x 28 - DIN 371
BAER HSSE Machine Tap - 35° RSP - UNF 1/4 x 28 - DIN 371
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 screw tap has a reinforced shank according to DIN 371. This means that the shank diameter is larger than the thread itself. This makes the screw tap run more stably. However, it limits the thread length that can be cut with it. It can be used for blind holes because the short chamfer and the spiral flutes ensure that the chip is discharged backwards out of the hole.
Every material shows individual chip behaviour. Therefore, screw taps must have the correct rake angle and - for even better results - a specially treated surface. This is the only way to achieve a good chip transport and to produce a thread that is true to gauge.
The high quality of the cobalt-alloyed HSSE 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 |
1/4 |
|---|---|
| Nominal diameter in inches |
0,25 |
| Nominal diameter in mm |
6,35 |
| Pitch |
28 |
| Pitch in mm |
0,907 |
| Dimension |
UNF 1/4 x 28 |
Characteristics
| Product group |
Screw taps |
|---|---|
| Product type |
Machine taps |
| Thread standard |
UNF: American Fine Unified National thread according to ANSI B1.1 |
| Tolerance |
2B |
| Direction |
Right |
| Standard |
DIN 371 |
| Tensile strength at room temperature |
up to 900 N/mm² | 27.1 HRC |
| Material |
HSSE bright |
5.5 mm
Blind hole up to 3 x D
Form C 35° RSP
2-3 threads
Chips are removed upwards against the cutting direction
External cooling and lubrication
HSSE 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
Examples of applications
- Thread on Land Rover engine block
- Thread with UNF ¼-28 thread
Technical drawing
| D1 |
UNF 1/4 x 28 |
|---|---|
| D2 |
7 mm |
| L1 |
80 mm |
| L2 |
10 mm |
| Diameter |
1/4 |
| Square |
5,5 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
- UNF - Unified National Fine Thread Series ANSI B1.1 American 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
