Deep Hole Drilling Guidelines
Step 1: Approach
- 50 RPM max
- 12 IPM (300 mm/min)
- Feed the longer drill within 1/16" (1.5mm) short of the workpiece at a maximum of 50 RPM and 12 IPM (300 mm/min) feed rate.
Step 2: Feed-In
- Speed at 75% of recommended start
- Feed at 50% of recommended start
- Drill 3/4" deep at 75% recommended speed and 50% recommended feed to establish the hole.
Step 3: Deep Hole Drilling - Blind
- 100% RPM
- 100% IPR (mm/rev)
- Drill to full depth at recommended speed and feed for longer drills (according to Allied Machine speed and feed charts).
- No peck cycle recommended.
Step 4: Deep Hole Drilling at Breakout
- 50% RPM
- 100% IPM (mm/rev)
For through holes only:
- Reduce speed by 50% prior to breakout.
- Do not break out more than 1/8" (3mm) past the full diameter of the drill.
Step 5: Drill Retract
- 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.