Allied Machine Opening Drill

Product system overview

Opening Drill is an Allied Machine adjustable indexable system for enlarging existing holes without a sequence of boring passes. Replaceable cartridges span multiple diameter ranges, and the coolant-through bodies are offered with straight and machine-spindle shanks.

Industries and applications

• Enlarging existing holes where eliminating multiple boring passes can reduce cycle time.
• Large-diameter work requiring adjustable cartridge coverage across several nominal sizes.
• Milling-machine setups using straight, CAT, BT, HSK, DIN, or ABS shank configurations available in the catalog.

Published technical profile

• Published diameter range: 50.80-142.75 mm (2.000-5.620 in).
• Four public body series divide the diameter range from OP1 through OP4.
• Shank options include straight, CAT40, CAT50, BT40, BT50, HSK63, HSK100, DIN50, and ABS63.
• Uses coolant-through straight-flute bodies in short and long configurations.
• Insert grades, coatings, and general-purpose or high-rake geometries are selected separately from the body.

Selection notes

Use Opening Drill when a prepared hole already exists and adjustable large-diameter enlargement is more efficient than repeated boring passes.

Validate stock allowance, existing-hole position, final tolerance, finish, machine interface, and setup method before selection.

Variables to validate

• Opening Drill enlarges a pre-existing hole and is not a substitute for drilling from solid.
• Cartridge setup, presetter or spindle adjustment, insert condition, and measured diameter are critical to final size.
• Hole straightness, finish, stock condition, and interrupted engagement depend on the quality and location of the existing hole.

Official product references

• Allied Opening Drill official product page
• Allied indexable drill directory