Product Description
BA Coventry Chasers for 1/4" Diehead – HSS Four-Piece Set
Right-hand BA Coventry chasers designed to fit a compatible 1/4" Coventry diehead. Manufactured from uncoated high speed steel, each four-piece set is supplied in a case for the selected British Association thread size.
These chasers cut external BA threads for precision engineering, model making and replacement component manufacture. Choose from 0BA, 1BA, 2BA, 3BA, 6BA, 8BA, 9BA and 10BA.
Specifications
| Product type | Coventry diehead chasers |
|---|---|
| Diehead fit | 1/4" Coventry diehead |
| Thread system | British Association (BA) |
| Thread direction | Right hand |
| Material | High speed steel (HSS) |
| Coating | Uncoated |
| Set contents | Four chasers for one selected BA thread size |
| Packaging | Supplied in a case |
Available BA Sizes and Thread Pitches
| BA Thread Size | Pitch (mm) | Approximate TPI |
|---|---|---|
| 0BA | 1.00 | 25.40 |
| 1BA | 0.90 | 28.22 |
| 2BA | 0.81 | 31.36 |
| 3BA | 0.73 | 34.79 |
| 6BA | 0.53 | 47.92 |
| 8BA | 0.43 | 59.07 |
| 9BA | 0.39 | 65.13 |
| 10BA | 0.35 | 72.57 |
BA pitch is specified in millimetres. TPI figures are approximate conversions for reference.
Key Features
- Four-piece chaser set for the selected BA thread size.
- Fits compatible 1/4" Coventry dieheads.
- Uncoated HSS cutting tools.
- Produces right-hand external BA threads.
- Supplied in a case for storage.
Typical Applications
- Model engineering and precision component manufacture.
- Making replacement BA-threaded screws, studs and small parts.
- Restoration work requiring British Association threads.
Selection and Use
The 1/4" designation identifies the diehead fit, not the thread diameter being cut. Check compatibility with your diehead before ordering.
Install the chasers in their numbered positions and set the diehead according to its operating instructions. Use cutting speeds and lubricant suitable for the workpiece material, then check the finished thread with an appropriate gauge.
Ordering
Select the required BA size from the available options. Each purchase supplies one four-piece set for that thread size. Diehead not included. Limited stock available.
Thread Standard
BA thread form: BS 93, with a 47.5-degree included thread angle. No separate manufacturing standard has been verified for these chasers.
