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All Products ➞ Bordo ➞ Drills ➞ Specialist ➞ Stub Drills ➞ Black Metric HSS Bulk
12.5mm HSS Black Stub Drill
| Part Number: | 2021-12.50 |
| Brand: | Bordo |
| Barcode: | 9326518037767 |
| Pack Qty: | 5 |
| Feed per revolution mm: | 0.24 |
| Spindle Speed Aluminium/Brass RPM: | 1554 |
| Spindle Speed Cast Iron RPM: | 612 |
| Spindle Speed Free Cutting Steel RPM: | 1096 |
| Spindle Speed Malleable Iron RPM: | 688 |
| Spindle Speed Med. Carbon Steel RPM: | 764 |
| Spindle Speed Stainless Steel RPM: | 306 |
| Spindle Speed Tool Steel RPM: | 459 |
| Spindle Speed Wood/Plastic RPM: | 2319 |
| Diameter (mm): | 12.5 |
| Flute Length (mm): | 51 |
| Overall Length (mm): | 102 |
About this item:
- 12.5mm HSS Black Stub Drill
- Stub drills (screw machine twist drills) have a shorter overall length than Twist drills for maximum rigidity and longer tool life.
- 135° Split Point (crankshaft point).
- Split point is self centering and the short distance from the drill axis to the outer corners results in faster penetration, reducing the need for end thrust.
- They are designed primarily for machining operations in lathes (screw machines) but can also be used in manual hand held drills.
- Bordo Stub Drills have two helical flutes with 30 degrees of helix angle. This provides fast chip ejection and very stable drilling operation.
- Black Finish Stub Drills (also called blue finish) achieve their distinctive colour by steam tempering, a thermal process resulting in a porous tool coating.
- Black finish tools are generally recommended for ferrous applications where the oxide layer aids chip flow and heat dissipation.