Round Die BS 1127 HSS - BA 0 x 25.4

• General-purpose use
• For machinable materials up to 800 N/mm²
• Unalloyed and low-alloy steels

Advantages:

• Precise BA external thread according to BS 93
• Ground HSS-G for long tool life and consistent cutting performance
• Form A – slotted: allows fine adjustment of cutting clearance
• Clean thread surface and reduced cutting forces
• Technical Information (PDF)

“Form A – slotted” refers to a round die with a longitudinal slot that allows a slight elastic expansion of the die body. This enables fine adjustment of the cutting clearance and gives improved control of thread quality and chip flow. Particularly useful for delicate diameters or where high precision is required.

1. Preparation: Machine workpiece to core diameter, add a 30–45° chamfer and secure in clamp.
2. Alignment: Insert die into the holder so that it sits flat and centered; ensure it is perpendicular to the workpiece.
3. Cutting: Apply cutting oil; rotate about 1 full turn forward, then ¼ turn back to break chips; maintain steady feed.
4. Finishing: Continue until thread length achieved, reverse the die and clear chips.
5. Inspection: Check with appropriate BA nut or gauge; clean the thread thoroughly.

• Thread Type: BA – British Association Fine Thread (BS 93)
• Standard: BS 1127
• Form: Form A – slotted
• Material: HSS-G
• Nominal Size: BA 0
• Outside Diameter: 20.6 x 6.35 o/d
• EAN: 4022835890003
• Article Number: 89000

• 1× Round Die HSS-G – BA 0 x 25.4 (Form A, slotted)

What materials is this die suitable for?
Engineered for machinable materials up to 800 N/mm², e.g., unalloyed and low-alloy steels.

What does “Form A – slotted” mean?
A die with a longitudinal slot enabling fine adjustment of cutting clearance for improved precision and chip control.

Which standard applies?
Die according to BS 1127, cutting fine BA threads per BS 93.

Is cutting oil necessary?
Yes – lubrication improves thread quality, surface finish and tool life.

Where can I find technical data?
Refer to the Technical Information PDF.