Step 1: Pilot Hole

  • 100% RPM
  • 100% IPR (mm/rev)

Details:

  • Establish the pilot hole using the same diameter short drill to a depth of 2xD minimum.
  • Utilize a pilot drill with the same or larger included point angle.

Coolant: ON

DHD TA Coolant ON
 
DHD SS TA 1
 

 

Icon Warning Step 2: Feed-In
  • 50 RPM max
  • 12 IPM (300 mm/min)

Details:

  • Feed the longer drill within 1/16" (1.5mm) short of the established pilot hole bottom at a maximum of 50 RPM and 12 IPM (300 mm/min) feed rate.

Coolant: OFF

DHD TA Coolant OFF
 
DHD SS TA 2
 

 

Step 3: Deep Hole Transition Drilling

  • 50% RPM
  • 75% IPR (mm/rev)

Details:

  • Drill additional 1xD past the bottom of the pilot hole at 50% reduction of recommended speed and 25% reduction of recommended feed.
  • Minimum of 1 second dwell is required to meet full speed before feeding

Coolant: ON

DHD TA Coolant ON
 
DHD SS TA 3
 

 

Step 4: Deep Hole Drilling - Blind

  • 100% RPM
  • 100% IPR (mm/rev)

Details:

  • Drill to full depth at recommended speed and feed for longer drill according to Allied speed and feed charts.
  • No peck cycle recommended.

Coolant: ON

DHD TA Coolant ON
 
DHD SS TA 4
 

 

Step 5: Deep Hole Drilling at Breakout

  • 50% RPM
  • 75% IPR (mm/rev)

Details:

For through holes only:

  • Reduce speed by 50% and feed by 25% prior to breakout.
  • Do not break out more than 1/8" (3mm) past the full diameter of the drill.

Coolant: ON

DHD TA Coolant ON
 
DHD SS TA 5
 

 

Icon Warning Step 6: Drill Retract
  • 50 RPM max

Details:

  • Reduce speed to a maximum of 50 RPM before retracting from the hole.

Coolant: OFF

DHD TA Coolant OFF
 
DHD SS TA 6
 
Icon Warning Tool failure can cause serious injury. To Prevent:
 
  • When using holders without support bushing, use a short T-A® holder to establish an initial hole that is a minimum of 2 diameters deep.
  • Do not rotate tool holders more than 50 RPM unless it is engaged with the workpiece or fixture.