Deep Hole Drilling Guidelines
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.
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.
Step 3: Deep Hole Transition Drilling
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.
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.
Step 5: Deep Hole Drilling at Breakout
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.
Step 6: Drill Retract
Details:
- Reduce speed to a maximum of 50 RPM before retracting from the hole.
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.
Visit
www.alliedmachine.com/Support/Safety/Deep-Hole-Drilling-Guidlines/T-A®-and-GEN2-T-A®.aspx for the most up to date information and procedures. Factory technical assistance is available for your applications through our Application Engineering Team.