HOLEMAKING TOOLS

Indexable U Drills

Indexable drilling systems for productive medium and larger diameter holemaking on CNC machining centres, milling machines and suitable lathes.

A U-drill system combines a reusable drill body with replaceable carbide inserts, internal coolant and serviceable spare parts. Select the system by hole diameter, drilling depth, insert compatibility, workpiece material, coolant delivery and machine capability.

U-DRILL SYSTEM

Understand the Complete U-Drill System

U-drills should be selected as a complete cutting system, not as a drill body alone.

DRILL BODY Reusable Tool Body

The drill body determines nominal diameter, drilling depth, shank size, coolant delivery and insert seat geometry.

CENTRE INSERT Cuts Near the Hole Centre

The centre insert works at lower cutting speed near the drill axis and carries a different load from the peripheral insert.

PERIPHERAL INSERT Defines the Outer Diameter

The peripheral insert operates at higher cutting speed and strongly influences final hole diameter and surface condition.

COOLANT Internal Coolant Delivery

Coolant passages deliver fluid toward the cutting zone to support chip evacuation and temperature control.

SERVICE PARTS Screws & Replaceable Components

Correct screws and service parts help maintain secure insert seating and reliable tool performance.

DRILL BODY SELECTION

Choose the Drill Body First

Start with hole diameter and required drilling depth, then confirm shank size, coolant and insert system.

PREMIUM INDEXABLE U DRILLS Production-Oriented Systems

Select where tool-body quality, repeatability, coolant delivery and production reliability are higher priorities.

VALUE INDEXABLE U DRILLS Cost-Conscious General Drilling

Suitable where application demands are moderate and overall tooling cost is an important consideration.

INSERT SYSTEM

Match the Inserts to the Exact Drill Body

Insert shape alone is not enough. Confirm insert designation, size, seat, screw and cutter-body compatibility.

INSERT DESIGNATION Use the Complete Code

Match the complete insert code rather than selecting only by shape or visual appearance.

SEAT COMPATIBILITY Correct Pocket Geometry

The insert must seat correctly against the drill body to maintain cutting position and load support.

GRADE & GEOMETRY Match the Workpiece

Select carbide grade and chip geometry according to workpiece material, stability and cutting conditions.

HOLE SIZE & DEPTH

Match Diameter and Drilling Depth

Drill diameter, usable cutting depth and overall reach must all suit the required hole.

HOLE DIAMETER Match the Finished Hole Size

Select the drill body according to the required nominal hole diameter and acceptable tolerance.

DRILLING DEPTH Check Usable Cutting Length

Confirm actual usable drilling depth rather than relying only on overall tool length.

L:D RATIO Depth Changes the Cutting Conditions

As hole depth increases, coolant delivery, chip evacuation, rigidity and runout become increasingly important.

INSERT POSITION

Centre Insert vs Peripheral Insert

The two insert positions experience different cutting speeds, loads and failure modes.

CENTRE POSITION Lower Cutting Speed

Cutting speed approaches zero near the drill centre, so the centre insert requires good edge strength and stable cutting geometry.

PERIPHERAL POSITION Higher Cutting Speed

The outer insert runs at the highest cutting speed and strongly influences hole diameter and wall finish.

LOAD BALANCE Both Inserts Must Work Together

Correct insert seating, geometry and cutting data help balance forces across the drill body.

COOLANT & CHIP CONTROL

Maintain Coolant Flow and Chip Evacuation

U-drilling produces a high chip volume inside the hole, making chip control one of the main process considerations.

INTERNAL COOLANT Deliver Coolant to the Cut

Through-tool coolant helps cool the cutting edges and transport chips out through the drill flutes.

CHIP FORMATION Create Manageable Chips

Correct feed, insert geometry and material grade help produce chips that can leave the hole reliably.

CHIP PACKING Avoid Recirculation

Poor evacuation can increase torque, damage inserts and drill body seats, and reduce hole quality.

WORKPIECE MATERIAL

Choose the Insert Grade by Material

Keep drill-body compatibility unchanged, then select grade and geometry for the material being drilled.

P Steel

Carbon steel, alloy steel and general engineering steels.

M Stainless Steel

Austenitic, ferritic, martensitic and duplex stainless steels.

K Cast Iron

Grey cast iron, ductile iron and related materials.

N Aluminium & Non-Ferrous

Aluminium, copper, brass and other non-ferrous materials.

S Titanium & Heat-Resistant Alloys

Difficult-to-machine materials requiring careful grade and cutting-data selection.

SELECTION FACTORS

Check the Complete U-Drill Setup

Drill body, inserts, machine, coolant and workpiece must be considered as one system.

01 Hole Diameter

Match drill diameter to the required hole size.

02 Hole Depth

Confirm usable drill depth and required reach.

03 Insert Compatibility

Confirm centre and peripheral inserts match the exact drill body.

04 Workpiece Material

Select insert grade and geometry for the material being drilled.

05 Coolant Supply

Check pressure, flow and internal coolant delivery.

06 Machine Power

Larger diameters require sufficient spindle power and torque.

07 Machine Rigidity

Stable spindle, toolholder and workholding improve drilling reliability.

08 Runout

Excessive runout can create unequal insert load and poor hole quality.

09 Through or Blind Hole

Hole termination affects breakthrough, usable depth and chip evacuation.

SERVICE & MAINTENANCE

Protect the Drill Body and Insert Seats

The drill body is reusable, so maintaining the insert pockets and clamping components helps protect long-term tooling value.

INSERT POCKET Keep the Seat Clean

Remove chips and contamination before installing replacement inserts.

INSERT SCREWS Use Correct Spare Parts

Use the specified screw and clamping components for the selected drill body.

DAMAGED SEATS Inspect Before Reuse

A damaged insert seat can affect location, load distribution and cutting reliability.

QUICK SELECTION

Practical U-Drill Selection

Selecting a New U Drill

Start with hole diameter and depth, then confirm shank, coolant and compatible insert system.

Replacing Inserts

Identify the exact drill body and centre / peripheral insert codes before ordering.

Changing Workpiece Material

Keep the drill body unchanged, then review insert grade, geometry and cutting data.

Poor Chip Evacuation

Check coolant flow, feed, insert geometry and hole depth.

Poor Hole Size or Finish

Check runout, peripheral insert condition, insert seating and machine rigidity.

Need Service Parts?

Match screws and replacement parts to the exact drill body model.

PREMIUM INDEXABLE U DRILLS

Production-Oriented U Drill Systems

Premium reusable drill bodies for applications where tool-body quality, repeatability, coolant delivery and production reliability are higher priorities.

VALUE INDEXABLE U DRILLS

SPGT Insert System

Cost-effective indexable U drill bodies designed for compatible SPGT carbide inserts and general CNC holemaking applications.

VALUE INDEXABLE U DRILLS

WCMX Insert System

Cost-conscious U drill bodies designed around the widely used WCMX carbide insert system for general workshop and production drilling.

U DRILL INSERTS

Compatible Carbide Inserts

Select the insert family that matches the exact drill-body system. Confirm insert size, pocket compatibility, geometry and carbide grade before ordering.