Deep Hole Drilling System

High efficiency and excellent hole surface quality

Applications & Features

Small-diameter drilling

1. Single Tube System (STS)

The STS is also referred to as the BTA system in the deep hole drilling process. A large volume of coolant is pumped under high pressure to the cutting area in the workpiece. Chips are then forced out through the drill tube at the back and do not touch the workpiece providing an outstanding surface finish. STS is a stable method to create holes with high accuracy by using a dedicated drilling machine and a sealing with the workpiece.

2. Double Tube System (DTS)

The DTS is characterized by its two tube construction and is therefore known as the double tube system. A sealing system and pressure head, which is required in the Single Tube System (STS), is not necessary for the DTS and it is therefore suitable for conventional general purpose machines such as lathes or machining centers. In general, because of less efficient chip evacuation than the STS, the recommended max drilling depth is 1000mm. The unique DTC-R tube connector that is capable of supplying high pressure coolant can, however, successfully achieve drilling depths of up to 2000mm.

Inserts & Grades



  • For FineBeam series
  • High productivity inserts with chip breaker


  • For UNIDEX series


  • For TriFine series
Main Grades


  • P15 – P30 / M15 – M30 / K25 – K30 / S15 – S25
  • Good balance between wear and chipping resistance
  • Suitable for machining steel and stainless steel under general cutting conditions


  • M01 – M20 / S10 – S20
  • Good balance between wear and fracture resistance
  • First choice for machining heat-resistant alloy under general cutting conditions

BTA bodies


TRI FINE (Ø16 – Ø28 mm)

The direct-mounting drill head 3-cornered insert


FINE BEAM (Ø25 – Ø65 mm)

BTA heads with Indexable inserts and guide pads


UNIDEX (Ø38 – Ø293.9 mm)

BTA heads with Indexable inserts and guide pads


BTU, ETU, UTE, MBU (Ø8.0 – Ø65 mm)

Brazed BTA heads



• Tubes for STS or DTS
• Tube diameter Ø11 – Ø310 mm

Practical examples

Part:  Main spindle
Material: 15CrMo4
Drill body:  KUSTS56-62.00
Insert: 1123-32RG
Grade: UC1220 (DLX2)
Cutting conditions: Vc = 80 (m/min)
f = 0.15 (mm/rev)
Vf = 62 (mm/min)
øDc = 62 (mm)
H = 735 (mm)
Coolant: Wet (Internal)
Machine: BTA machine
Part: Casing Pipe
Material: Inconel 740H Alloy
Drill body: FNBM-13S-63.50
Insert: FBH130408R-HF-P
Grade: AH8015
Cutting conditions: Vc = 21.3 (m/min)
f = 0.2 (mm/rev)
Vf = 21.4 (mm/min)
øDc = 63.5 (mm)
H = 5690 (mm)
Coolant: Wet
Machine: BTA Machine

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