Boring is a machining process that enlarges a hole or improves the quality of an existing hole. For boring, whether rough or fine, there are a variety of flexible tool systems for a wide range of 

hole diameters.

Initial considerations for boring

These initial considerations will influence the selection of boring tools and how they are used when boring.

hole

Hole quality affects process type and tool selection.

Consider hole size, constraints, and quality requirements:

Boring diameter

depth

Tolerances, surface quality, position and straightness

Hole type

Determine whether the operation type is rough boring or fine boring:

Rough boring

The existing hole is machined with an emphasis on metal removal to prepare it for fine boring. Existing holes are machined by drilling, casting, forging holes, and flame cutting. Applicable to 

hole tolerances greater than or equal to IT9.

Precision boring

Machine existing holes to achieve tight hole tolerances and high surface quality. Small depth of cut, typically less than 0.5 mm (0.020 inch). Hole tolerances for IT6-IT8

Component

Determine the type of workpiece to be machined.

Shape and quality:

Does the material have good machinability and chip breaking performance?

Is the workpiece stable or are there thin-walled sections causing vibration?

Do I need a tool extension to machine the hole?

Is the workpiece reliably fixed? What stability issues need to be considered?

Does the part rotate symmetrically around the hole, i.e. can the hole be machined in a lathe?

Batch size – batch production (where optimized custom tools are proven to maximize productivity) or single hole machining?

Material:

machinability

Chip breaking

hardness

alloy element

machine tool

Important machine tool considerations:

Spindle interface

Machine tool capabilities

Is the spindle speed (rpm) sufficient for small diameter holes?

Coolant supply and pressure, coolant flow and pressure adequate?

Is the clamping of the workpiece stable enough?

Horizontal or vertical machine tool? Horizontal machines enable better chip evacuation

Power and torque, is the power enough for large diameter hole machining and a 3-edge boring tool?

Tool magazine, is space limited?