The Value Of Indexable-Insert Center Drills

Published 1/8/2010

The Value Of Indexable-Insert Center Drills

This indexable-insert center drill, said to be an industry first, combines the drilling performance advantages of solid carbide with the positioning repeatability and quick-change benefits common to indexable-insert tooling.

Derek Korn

Editor-in-Chief, Production Machining magazine

Indexable-insert center drills such as this one greatly reduce machine downtime by eliminating the tool measurement routines necessary when changing worn HSS or solid carbide drills.

Center drilling using this indexable-insert tool can also be performed on milling machines. High-pressure coolant delivered through the toolholder and directed to the insert tip improves chip evacuation and tool life.

A shop’s production levels are commonly taken into consideration when evaluating different types of cutting tools for a given operation. Consider center drills, which create a hole in the end of a workpiece with a specific diameter, depth and form to receive a lathe or grinding machine’s supporting center. Preliminary center drilling operations must be performed on all long workpieces before they can be turned or ground.

The two most popular types of center drills are HSS and solid carbide. Cost-effective HSS center drills tend to work fine for shops performing just a modest amount of high L:D turning or grinding. Such shops may consume only a few center drills each month. More expensive solid carbide center drills can be attractive to shops that process larger batches, allowing them to drill at higher speeds and feeds and to experience longer tool life. Both types, however, require some sort of measurement routine when changing a worn center drill so that a fresh one drills to the proper depth. (This might be done using a tool presetter or an in-process gage.) Maintaining the specified center hole depth throughout a production run is critical to ensure that a grinding wheel, for example, doesn’t impact a shoulder or some other workpiece feature, scrapping the part.

Taiwan’s Nine9 (exclusively represented in the United States by Everede Tool Company) has developed an alternate type of center drill geared toward high-production environments that eliminates the need to measure replacement drills. Its “i-center” is said to be the industry’s first indexable-insert center drill, combining the performance advantages of solid carbide with the positioning repeatability and quick-change benefits common to indexable-insert tooling. This new type of drill is suited for components such as transmission components, crankshafts and shafts for motion-control applications turned or ground in large volumes.

The i-center tool uses standard insert blanks that offer two drilling cutting edges. Inserts locate on two pins machined into the mating toolholder and are secured via a single Torx screw. Insert edge-to-edge positioning accuracy is 0.05 mm in the axial direction and 0.02 mm in the radial direction, making it unnecessary to re-measure after indexing or changing inserts. The i-center toolholders are made of hardened, high-alloy steel and have internal passages that deliver high-pressure coolant to the tip of the insert. This helps increase cutting speed and extend tool life while preventing chip “bird-nesting.”

Each insert drill tip has two cutting edges as well as reliefs designed to facilitate chip evacuation. This provides a quality hole finish and also helps prevent insert tips from breaking due to excessive heat buildup, which is the most common failure mode for center drills. The i-center inserts have a two-flute-effective design and are offered in diameters ranging from 2 to 10 mm. Standard forms include ANSI 60-degree, DIN332 Form R and DIN332 Form A+B, but special forms are also available. They have a K20F carbide substrate engineered for centering operations and a TiAlN coating, making them suitable for drilling cast iron, carbon/alloy steels, aluminum/aluminum alloys and copper/copper alloys.

Related Content

Holemaking 26 Apr 2023

Form Tapping Improves Tool Life, Costs

Moving from cut tapping to form tapping for a notable application cut tooling costs at Siemens Energy and increased tool life a hundredfold.

Holemaking 28 Jun 2023

Tungaloy Drills, Milling Inserts Provide Enhanced Stability

Tungaloy has expanded its DrillForceMeister and TecMill lines with new drill bodies and milling inserts.

Holemaking 18 Mar 2024

Heule Tool Enables Spot Facing of Difficult-to-Reach Areas

The manually actuated bkac spot facing tool is well suited for large boring mills and other open-air machines.

Holemaking 24 May 2023

Kennametal's Expanded Tooling Portfolio Improves Performance

The company has launch eight new products that expand on and support existing platforms across multiple applications.

Registration Now Open for the Precision Machining Technology Show (PMTS) 2025

The precision machining industry’s premier event returns to Cleveland, OH, April 1-3.

Workforce Development

Shop Tour Video: You've Never Seen a Manufacturing Facility Like This

In the latest installment of our “View From My Shop” series, explore Marathon Precision’s multi-process approach to manufacturing, where blacksmiths and hand-forged dies meet state-of-the-art CNC machining. Discover how restoring classic muscle cars and building custom art projects creates a dynamic shop culture — and draws top talent to this unique and innovative metalworking facility.

Shop Management Software

Setting Up the Building Blocks for a Digital Factory

Woodward Inc. spent over a year developing an API to connect machines to its digital factory. Caron Engineering’s MiConnect has cut most of this process while also granting the shop greater access to machine information.

91��Ƶ��վ��

The Value Of Indexable-Insert Center Drills

Share

Related Content

Form Tapping Improves Tool Life, Costs

Tungaloy Drills, Milling Inserts Provide Enhanced Stability

Heule Tool Enables Spot Facing of Difficult-to-Reach Areas

Kennametal's Expanded Tooling Portfolio Improves Performance

Read Next

Registration Now Open for the Precision Machining Technology Show (PMTS) 2025

Shop Tour Video: You've Never Seen a Manufacturing Facility Like This

Setting Up the Building Blocks for a Digital Factory

Country

Industries Served

Operations Performed

Welcome to 91��Ƶ��վ��!

The Value Of Indexable-Insert Center Drills

Share

SMW Autoblok Corporation

Featured Content

Featured Videos

HEIDENHAIN CORPORATION

Featured Content

CNC Engineering, Inc.

Featured Content

Featured Videos

T J Davies, Co., Inc.

Featured Content

ZEISS Industrial Quality Solutions

Featured Content

Featured Videos

QualiChem Inc.

Featured Content

Featured Videos

Mikron Corp.

Featured Content

Featured Videos

Related Content

Read Next

Country

Industries Served

Operations Performed

Welcome to 91��Ƶ��վ��!