分类: Boring

Four, Six, Eight, Steel, Heavy Metal, Carbide: The Fundamentals of Selecting the Correct Boring Bar

2/11/2025

Cutting Forces During Boring Operations Radial Tangential

photo courtesy Everede Tool

Boring bars are indispensable tools for enlarging and refining holes, a critical step in the machining process. They come in various types, each designed to address specific machining needs. Selecting the correct boring bar for use in your your turning application can make your life a lot less stressful.

Cutting Forces During Boring Operations

During boring operations, the tool encounters forces that can impact its effectiveness. Primarily, tangential and radial cutting forces exert downward and lateral pressure on the tool, potentially causing deflection away from the workpiece.

The Impact of Radial Force
Radial force plays a significant role, especially in scenarios with excessive tool overhang. This force can push the insert away from the cutting surface, leading to deflection and chatter. The extent of this deflection correlates directly with the tool's overhang, depth of cut, and feed rate. Minimizing overhang is crucial to mitigate these issues, ensuring stability and precision.

Tangential Force Dynamics
Tangential force, on the other hand, tends to displace the tool downward and outward, away from the workpiece's centerline. This displacement can compromise the tool's clearance angle, critical for maintaining the quality of the cut. When boring small diameter holes, maintaining a sufficient clearance angle is paramount to prevent the tool from making unintended contact with the hole's interior walls, preserving the integrity of the bore.

Some Recommendations for Optimal Performance

Minimize Tool Overhang: Employ the shortest overhang feasible for your operation to reduce the risk of deflection and chatter. Typically you should try to use the largest diameter boring bar possible to maintain rigidity off the boring bar. We'll dig more into this below.
Monitor and Adjust Feed Rate and Depth of Cut: Tailoring these parameters can help manage the radial and tangential forces encountered during boring.
Ensure Adequate Clearance Angle: Especially critical in boring small diameters, a proper clearance angle helps avoid undesirable contact with the workpiece.

By understanding and addressing the implications of tangential and radial forces, machinists can enhance the accuracy, finish, and overall success of boring operations. These adjustments not only improve tool performance but also extend tool life and enhance workpiece quality.

Selecting the Shank Diameter

Selecting the right shank diameter is crucial, and it involves evaluating the minimum machining diameter of the boring bar alongside the desired bore diameter. Optimal selection dictates choosing a shank diameter that is as large as possible.

Nevertheless, it's essential to exercise caution, as a shank diameter that is too close to the bore diameter will lead to chip control at least and chip packing at worst. Consequently, the choice of shank diameter should be tailored to the specific application requirement while leaving enough room for your chips to evacuate. Remember, if you're roughing you're going to be taking a bigger bite than you are if you are finishing.

A couple decades ago, I was having some issues with chip packing that I couldn't solve. I called in my cutting tool specialist, Charles Colerich. Charles took one look at the application and said "Just turn the bar upside down. Gravity works." No one ever said the insert needed to be facing upwards.

As a result, instead of the chips trying to evacuate over the top of the bar, the coolant washed them under the bar. Sometimes the best thing to do is step back and look at the problem in its simplest terms and apply some common sense. When he told the machinist to turn the bar over the shop foreman and I looked at each other and both had facepalm moment "why didn't; we think of that" together.

Selecting the Correct
Length: 4 - 6 - 8 -10+

Boring bars can be classified based on their material, structure, and construction. The type of boring bar determines the strength of the bar to handle strong cutting forces with minimal vibrations. The most popular boring bars used include steel boring bars, heavy metal bars, carbide bars, and damping bars.

When initially selecting the type of bar you need a good rule of thumb, that is also pretty simple, is 4-6-8-10+. Take the diameter of your boring bar and multiply it 4.

That's about the max depth you should try to bore with a steel bar.

Here's an easy to remember list of max depth of each type of bar:

Steel Boring Bars: Up to 4 X Diameter
Heavy Metal Bars: Up to 6 X Diameter
Carbide Boring bars: Up to 8 X Diameter
Devibe Boring Bars: Antivibration bars are generally best applied over 10 diameters depth.

Everede's Boring Bar Range

Everede Tool offers a diverse range of different types of materials on the shanks of their boring bars The range of tools are notable: From small diameter capabilities, accommodating minimum bore diameters from as small as 0.180" up to sizes exceeding 1.500", depending on the series and specific model. The selection includes options with a 5° positive axial rake, angles designed for facing and through-hole boring, and configurations suitable for boring to the shoulder with 0° angles.

The choice of boring bars in CNC machining is a critical decision that directly influences the quality and efficiency of the machining process. Everede Tools' boring bars stand as a testament to precision engineering, offering a comprehensive range of options with features such as anti-vibration technology, modular design, and high-quality materials. By investing in Everede Tools' boring bars, machinists can elevate their CNC machining capabilities, achieving superior results and staying at the forefront of innovation in the industry.

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Jeff Terrace joins the Browne & Co Team!

6/11/2020

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by Bernard Martin

In January of this year we welcomed a new member to our Browne & Co. sales team and with manufacturing companies opening up again, it's about time we introduce you to Jeff Terrace!

Jeff graduated from Ohio University with a Bachelor of Science in Mechanical Engineering in 2008. He started his professional career at Lincoln Electric in Euclid, OH as a process & project engineer in the machining and mechanical parts group. He was tasked with new product development for all the machined parts in the plant as well as new equipment implementation and process improvement.

After Lincoln Electric, Jeff joined the application engineering team at Ingersoll Cutting Tools in both the general marketplace and Automotive division. The majority of his time at Ingersoll was spent working with local manufacturing companies as well as the Big Three automakers on custom tooling applications for high and low volume production, custom carbide, CBN and PCD tooling.

Jeff Terrace Browne & Co Manufacturers Agent Rep

Jeff Terrace joined our Browne & Co team in January 2020

Jeff Terrace
cell: 216-556-3344
[email protected]

Just before joining Browne & Co in January 2019, Jeff worked at Hoffmann Group, a German cutting tool, hand tool, workstation and storage solutions manufacturer.

Jeff has been working as an InovaTool representative since February of 2019 and recently joined Browne & Company at the beginning of 2020 as our Cutting Tool Specialist. Please send Jeff and email or give him a call to introduce yourself or pick his brain about an application question.

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Are You Boring Or Profiling Nickel/Chrome Based Materials?

5/19/2020

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The Dummel Ultramini Xtraline Typ X050 is the Ferrari of mini grooving and boring tools. The modified geometry is specifically designed for high Nickel/Chrome based Superalloys.

They come with an internal coolant bore, chipbreaker, special carbide grade and an optimised cutting edge and shank geometry.

We have seen 200% increase in tool life vs our competition in machining the most difficult to machine materials.

Please call Browne & Company or email us for your nearest, authorized Dummel distributors:
440-463-3970
[email protected]

Ultramini Xtraline Catalog Pages

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HB Rouse Carbide Cutting Tool Brand Reintroduced by Arno Werkzeuge USA

6/27/2018

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Arno Werkzeuge USA has reintroduced the H.B. Rouse brand of American-made carbide cutting tools and inserts.

Arno Werkzeuge USA has reintroduced the H.B. Rouse brand of carbide cutting tools and inserts.

Formerly sold and marketed under the Arno-Rouse name, the company has reintroduced Rouse as a standalone product offering a broad range of carbide boring bars, tools and inserts for manual turning operations.

The carbide insert turning tools have triple-sided inserts for quick change turning operations.

Triple-tip boring bars offer an improved triangular insert located within a precision-machined pocket to eliminate shifting under heavy cuts; the insert requires the simple removal of one screw for indexing.

Boring bars feature carbide inserts that provide three cutting edges instead of only one (as is common with brazed-tip tooling).

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Four, Six, Eight, Steel, Heavy Metal, Carbide: The Fundamentals of Selecting the Correct Boring Bar

Cutting Forces During Boring Operations

Selecting the Shank Diameter

Selecting the Correct
Length: 4 - 6 - 8 -10+

Everede's Boring Bar Range

Jeff Terrace joins the Browne & Co Team!

Are You Boring Or Profiling Nickel/Chrome Based Materials?

HB Rouse Carbide Cutting Tool Brand Reintroduced by Arno Werkzeuge USA

Author

Archives

Categories

Four, Six, Eight, Steel, Heavy Metal, Carbide: The Fundamentals of Selecting the Correct Boring Bar

​Cutting Forces During Boring Operations ​

Selecting the Shank Diameter

Selecting the Correct ​Length: 4 - 6 - 8 -10+

Everede's Boring Bar Range

Jeff Terrace joins the Browne & Co Team!

Are You Boring Or Profiling Nickel/Chrome Based Materials?

HB Rouse Carbide Cutting Tool Brand Reintroduced by Arno Werkzeuge USA

Author

Archives

Categories

Cutting Forces During Boring Operations

Selecting the Correct
Length: 4 - 6 - 8 -10+