Indexable Cutting Tools & Tooling - CNC Cookbook

An indexable endmill making its way through a pocket...

For more information, please visit Guangzhou Ruiyi Technology Co., Ltd..

Large endmills can remove a lot of material, but they're also very expensive. It didn't take the machining world long to decide they're too expensive and to come up with indexable cutting tools as the answer. With indexable tooling, the cutting edges are removable carbide inserts.  Most of the tool lives on when the cutter dulls, and only the inserts need to be replaced.

Even then, most inserts have multiple cutting edges that can be "indexed" into place to provide a fresh edge.  Hence the name Indexable Cutting Tools.

Face Milling

The companion to indexable endmills are called "face mills" because they're used for "facing." Facing is surfacing a large flat area, typically the top of the part.

Here are typical face mill with 45 and 90 degree inserts...

it's possible to do more than just surfacing with a face mill, so sometimes they're referred to as "side and face milling cutters."

If you're going to be purchasing a face mill, it's worth looking at our Complete Guide to Face Milling.

Face mills can be sensitive to how they enter a cut, especially with tough materials that can chip the inserts.  Be sure to check out the tips in our toolpath article on how to optimize your face mill programming.

Indexable End Mill / Insert End Mill

Indexable end mills are used in lieu of solid end mills.  For efficient roughing, it's convenient to have an indexable endmill that are at least 5/8's to 3/4 inches in diameter. That's the size where buying solid endmills starts to be expensive, but it is small enough that what's left for smaller solid endmills to clear is little enough that they can do that job quickly. So, you rough with the indexable and finish with the solid endmill.

Depending on the jobs you have, larger indexable endmills may make sense too. It's basically a tradeoff between your machine's capabilities, how tight the confines of your workpiece are, and the cost to keep a bunch of indexable tooling and an inventory of suitable carbide inserts for them.

Indexable End Mills come in many shapes and sizes and with many different insert shapes as well.  Here are some of the specialized sub-types:

Button Cutters, Copy Mills, and Toroidal Cutters: Round Insert Milling Cutters

Indexable End Mills with round inserts are often called "Button Cutters", "Copy Mills", or "Toroidal Cutters."  They have a number of advantages:

• Their large radius creates a great surface finish.
• Their round shape makes them very strong, so they're well suited to materials that are hard on cutters.
• The round shape creates forces that are more axial than radial.  For light machines, this is their stiffest direction for resisting cutting forces.

We've got an entire article on these versatile cutters:

[ More about Button Cutters, Copy Mills, and Toroidal Cutters: Round Insert Milling Cutters ]

Indexable Drills

Kyocera Indexable Drill...

Given just how often our machines need to make holes and the advantages of indexable tooling for end and face milling, it should come as no surprise that indexable drills are available too. These are generally best used for larger holes. Not a lot to know here at the basic level other than to keep in mind that they exist and can save you quite a lot of time on a job.

See our [ Full Article on Indexable Drills ] for details.

A Few Words About Indexable Tooling Economics

There are some great deals on indexable tooling and inserts on eBay…

Indexable Cutting Tools will help you save money over running solid end mills all the time.  They have many other advantages too.  But all indexable cutting tools are not created equal when it comes to saving money.

One thing that's important to keep in mind is whether the indexable milling cutter uses a standard insert shape available from many manufacturers, or a proprietary shape you can only get from one manufacturer.  The latter may be capable of higher performance that may justify its price, but you can be certain its price will also be higher.

Managing indexable inserts is another cost saving opportunity.  The more insert types you have to stock, the more expensive the inventory.  Look for opportunities to standardize on multiple cutter types that all use the same inserts and you'll save on inventory at the very least.

It's also easier than you'd think to make your own indexable tooling.  Here's a dovetail cutter I made that uses TPGB inserts:

TPGB dovetail cutter goes to work...

I made it in just a few hours on my manual mill and lathe before I had CNC.  With CNC, it would be even faster to make one.

Worldia, founded in China, is a leading manufacturer of high-quality, superhard cutting tools, components and materials (PCD, CVDD, MCD, PCBN) with 5 manufacturing locations and more than employees worldwide, thereof 10% in research and development, holding over 250 patents. Since , the company is listed on Chinese stock market as one of the first 25 high-tech companies. Innovation, a focus on technology, highest quality standards and consistent customer orientation have enabled Worldia to grow steadily and invest in new product areas and locations. Worldia Europe as first foreign subsidiary serves the European market and offers application technology support and on-site warehousing since .

Interview with Michael Grimm, Chief Strategy Officer of Worldia Group.

Easy Engineering: Price: tell us something about the costs from a ROI perspective?

Michael Grimm: Similar as when buying other products, also for cutting tools many buyers look at the purchase price as leading criterion for their decision. However, this can be misleading and even cause much higher ongoing cost if following criteria are not being considered at the same time:

For more Indexable Toolsinformation, please contact us. We will provide professional answers.

• Tool life per cutting edge
• Number of indexes or re-grinds per cutting edge
• Regrinding/ recoating cost, if any

This all directly impacts the purchasing budget of tools and as a rule of thumb only makes up around 3% of total manufacturing cost.

In addition, tools have strong influence on other cost that do not fall within tooling purchasing budget. Such cost include:

• Tool setup cost
• Tool change time 
• Coolant cost
• Time to remove chips from machine
• Machining time/ number of machines required for the operation/ number of operators needed/ ROI of machine purchases.

These costs have a much bigger impact on overall manufacturing cost, but are often not considered when taking purchasing decisions as they might not be part of the buyer’s KPIs.

So even for cutting tools, the old saying often applies: “Who buys cheap buys twice”.

E.E: What about the costs for maintenance / future upgrades etc.

M.G: Maintenance cost of cutting tools include

• Regrinding of HSS, carbide, ceramics, PCD and PCBN tools
• Retipping (de-brazing of worn and brazing of new PCD and PCBN cutting egdes)
• Recoating of HSS and carbide tools
• Maintenance of indexable cutter bodies (regular check, exchange of screws and other spare parts, repair as needed)

Especially the last topic is very critical to the accuracy and lifetime of these tools. Well-maintained cutter bodies often can last decades in mass production, whereas e.g. tools with worn-out screws or insert pockets do not only lead to higher insert consumption, but in worst case can also damage or destroy expensive workpieces.

E.E: Quality: tell us something about the quality behind your products / solutions.

M.G: WORLDIA tools are known for their superior quality that stands out from many other China suppliers. “World-leading quality made in China” is one of our 7 “mantras”. WORLDIA tools run successfully in leading global companies, meeting their highest quality standards.

WORLDIA is certified according to ISO and related standards and has really introduced quality as part of it’s culture that is being lived by every employee every day.

E.E: Characteristics: what important features should clients search and what features do your products / solutions offer?

M.G: When it comes specifically to superhard tools, the core of WORLDIA’s portfolio, I think there are 2 main directions in product selection:

1. Availability of high-quality products for universal use. Easy choice, fast delivery.

With our MANANOVA portfolio of stock-keeping ISO PCD and PCBN inserts, we have an immediate first solution for 60-70% of all related application cases which is very important e.g. to the competitiveness of job shops and Tier 1-2 suppliers. Thanks to our simplified product selection guide, usually no on-site application support is necessary. Products are being shipped from German warehouse latest 1 workday after order entry.

• Capability to design and manufacture tools exactly to the customer’s needs.

This starts with the detailed analysis of the component to be manufactured, the machine, the clamping and the intended process and requires an open communication between customer and supplier to achieve the best result. For this, support by application experts in the region is key. Meanwhile, WORLDIA has a strong application team in Europe, supported by a network of technically trained distributors.

Functionality: tell us something about ease of use, integration with other solutions or other innovative features of your products / solutions?

Ease of use is a topic that has direct impact on quality but also on cost. Take our PCD monoblock tools as an example: Often different functions such as milling, countersinking and reaming are integrated into 1 tool. This combination saves tool changes on one hand, and on the other hand does not even require time-consuming tool setup. These tools come “out of the box, ready to perform”. Other tools, like our indexable BE-series PCD face milling cutters include fine-adjustment capability which, however, is only being used when really needed, e.g. for finish milling applications. If an axial runout of 20 µm is sufficient for an application, the same standard cutter can also be used as fixed-pocket cutter without any adjustment. This feature helps our customers to minimize inventory of cutter bodies.

Another feature that operators really like is the light-weight design of our milling cutters. A 250 mm diameter cutter doesn’t weight more than 6,5 kg.

By shifting from (wet) grinding to (dry) hard turning with PCBN inserts, customers can save significant cost e.g. for coolant and grinding waste disposal. Lasered chipbreakers ensure that chips don’t disturb the machining process.

E.E: Comparison: what key features do your products / solutions have compared to others on the market?

M.G: Some unique features have already been mentioned before. Other examples are our PCD micro drills that start already from 0,1 mm diameter and our PCD helical end mills with “twisted” PCD cutting edges. Due to WORLDIA’s capability to manufacture its own PCD and CVDD materials, we are often more competitive versus companies that have to buy these materials.

Again, these are only a very few examples. To learn more, please check our website or visit us at AMB Stuttgart 10.-14.09.24 in hall 1, booth Z130.

E.E: Feedback: what was the feedback from clients about your products / solutions?

M.G: Well, first I came to know WORLDIA was approx. 10 years ago. In all these years, feedback from clients has always been very positive, especially on quality, but also on price-performance ratio.

E.E: What purchasing advice do you have for clients in your fields of activity?

M.G: As I replied to your first question, I would consider it short-sighted only to look at the price of the individual cutting tool. Important is the “total cost of ownership” respectively the tooling cost per manufactured component. Furthermore, I have seen biggest benefits for customers resulting from stable and trustful customer/ supplier partnerships with joint development projects etc.

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