Introduction to CNC Cutting Tools

In the modern manufacturing world, Computer Numeric Control (CNC) machines are widely used. CNC machines are computer-controlled, high-precision tools designed to make accurate movements in a repeated pattern. During the 1940s and 50s, CNC cutting tools were introduced in the industrial world. These high-precision machines were used for various machining operations. In recent years, these automated machine tools have been widely applied in all manufacturing industries.

Although CNC machining is very similar to 3D printing, the key difference lies in their high precision, advanced speed, and cost. Generally, the CNC machine is a better choice for more precise, efficient, and top quality projects.

There are various types of CNC cutting tools and these tools are designed for high-precision machining. Most often, manufacturers make use of CNC cutting tools for near-perfection projects requiring a high degree of accuracy and precision. Which of the CNC cutting tools used is dependent on the project, operation pattern, and, most importantly, the CNC machine itself. Before we discuss CNC cutting tools, let’s take a closer look at the various types of CNC machines.

Types Of CNC Cutting Machines

Basically, there are five broad types of CNC machines and the CNC cutting tools used are dependent on the type of machine, nature of the project, and overall precision required for the project. The five broad types of CNC machines are:

CNC Milling Machine

  These are arguably the most common CNC machines on the market. Specific programs in terms of letters and numbers are translated in the CNC mills. A programming language called G code is utilised in these machining operations.

Being pre-programmed, rotary cutting tools cut pieces of metals into different shapes and sizes.
Unlike other manual-operation milling machines, the CNC milling machine has greater precision and high accuracy.

CNC Routers

Like most manually operated routers, CNC routers cut materials such as wood, plastic, steel, aluminium, foam, and composites. But with the CNC routers, you’ll be able to cut more prototype models and advanced shapes of materials. Like the CNC mill, the CNC router runs with a numeric computer control, improving productivity as it produces more items in less time. Normally, industrial CNC routers have 3-axis machines. But technical and high complex machining operations use 4-axis, 5-axis, and 6-axis machines.

 CNC Lathes

Operating with the various programming language, these machines produce more precise cuts. These are rotatory machines that make precise cuts, 3D shapes and moulds of materials by their spinning actions. These machines are ideal to manufacture spherical or cylindrical objects.

Plasma Cutters

CNC plasma cutters use a plasma torch to cut heavy metals like steel. This functions through the conversion of gases that the cutter blows at high speed into plasma. The plasma, which is usually very hot, melts any metal the machine is cutting. Pieces of metals at the cutting site are also blown away by the high pressure.

Electrical Discharge CNC Machines

Electrical Discharge Machines can be virtual or wire machines. These machines use electric sparks to cut through metal sheets. With this, they create specific shapes and sizes of materials.

Aside from these five types of CNC machines, other types are available in the market. With the advent of CNC machines, manufacturing has been made easier as more precise and accurate projects can be done at the least possible time.

CNC CUTTING TOOLS

Since ancient times, cutting tools have existed. They’re one of the oldest inventions in human history andnd there has been a dramatic change in the type of cutting tools we use. Initially, we built them with stones, so these metallic tools are of much value in the manufacturing world.

Although all cutting tools serve one purpose, to cut through a material, there is a huge difference in their purpose.
Normally, for a cutting tool to be effective, it has to:

• be 30% to 50% harder than the material it will work on.
• be easily fabricated.
• have high thermal conductivity.
• have low coefficient of friction.
• be very resistance to wear.
• be chemically inert and stable.

In practice, different CNC cutting tools perform cutting operations. Before considering which CNC cutting tools to use for a specific operation, you’ve got to understand the material that manufacturers used when producing the tool. Based on that material, we classify cutting tools into:

Carbon Steel Tool

These cutting tools are inexpensive and are mainly for low-speed operations. They have a carbon composition of 0.6 – 1.5% with a little amount of manganese and silicon. They’re mainly in twist drills, forming tools, milling cutters, and turning.

High-Speed Steel (HSS)

It‘s composed of high carbon steel with a reasonable amount of element alloys like chromium, tungsten, and molybdenum. With this combination, it improves hardness, wear resistance, and toughness. It also offers higher removal rate for metals and other materials. To improve its property, you’ve got to apply certain surface treatment.

Ceramics

These chemically inert tools are corrosion-resistant and 10x faster than high-speed steel. Usually,aluminum oxide and silicon nitride make up ceramics materials. Projects that require top-notch finish operations normally use ceramics.

Cemented Carbide

Designed for high-speed operations, these carbide tools are extraordinarily hard and can withstand temperatures of up to 1000^oC. Normally, tantalum, titanium, and tungsten make them up. Operations that require a high-quality surface finish also use them.
Other classifications include diamond tools, cubic boron nitride (CBN), sialon, and cermets.

CNC Cutting tools come in various shapes and sizes and you can use them for various milling and lathe cutting operations.

Some CNC cutting tools are:

End Mills

Rotational cutting tools that you can use for the removal of materials. Although very similar to the drill bit, the end mill is for more versatile machining operations. Unlike the drill bit that cut axially to the material, end mills are lateral cutting tools that cut in any direction. Due to their design, some end mills cannot cut materials axially.

Generally, there are different types of tip shapes for an end mill and each end mill depends on the desired end-product. The various types of end mills are:

• Ball nose mills: Ideal for 3D contour work, ball nose mills have rounded ends that produce top-notch curved surfaces.

• V-bit: Depressions that these tools make are V-shaped. V-bit can be 90^o or 60^o and each depends on the angle of depression that a material needs. Although they often use them to engrave signs on materials, they’re ideal for projects that need excellent sharp edges.
• Straight Flute End Mills: These CNC cutting tools are general purpose tools that offer top quality edges.
• Down-cut and up-cut end mills: These spiral tools can either produce a smooth-surface finish by carrying the residue chips down or a rough-surface finish by carrying the residue up and away from the specified area.

The basic anatomy of an end mill consists of a flute (helical grooves), cutting edge (teeth), diameter, shank, cut length, and the overall tool length.

2. Twist Drills: These rotary CNC cutting tools have two flutes and two cutting edges. Through their unique designs, coolants can quickly reach the point of cut action. Manufacturers usually use these cutting tools to lower production costs and perform operations with top-notch finishing.

The twist drill is comprised of three major parts: The shank, the body, and the point.

3. Fly Cutter: These single point cutters are on a mill and general purpose fly cutters provide excellent surface finishes.

This CNC cutting tool goes across the surface of a material through a clockwise rotation, making the material surface smooth and flat. The fly cutter is for CNCers who want to produce an outstanding fine finish.

4. Cutting Fluids and Coolants: Typically not a CNC cutting tool, cutting fluids flush material chips away from the cutting zone. They also offer additional benefits like:

• Reduction of thermal deformation in a workpiece.
• Improvement of the tool life.
• Surface finish improvement.

Tool holders typically hold CNC cutting tools before fitting them into the CNC machines. The quality, design, and manufacturer’s specifications about the tool holders are critical to an overall success of the machining operations.

Why Should You Make The Right Choice with CNC Cutting Tools? 

Cutting tools play a vital role in the quality of projects done. Although buying these items might be pricey, you cannot overlook their importance. In fact, the quality of your project depends on the kind of cutting tool you use.

The industrial world is highly competitive and, to succeed, manufacturers and end-users have to build top-notch products through proper planning and precise cutting. Since cutting tools form the backbone of a professional project, you need to pay special attention to these little items that can make or mar your projects.

Greater productivity, high precision, accuracy, and efficiency in machining operations are the driving force needed to craft top-notch products. You can easily achieve these features by having the right cutting tools and having an in-depth knowledge about  CNC cutting tools is the first step towards success in a competitive industry.

Introduction to NMTB Tool Holders

NMTB tool holders (National Machine Tool Builders Association), another name for “Quick-Change”, come in different sizes and they’re mainly single-flanged. You can tell the taper size from their number: NMTB 25, NMTB 30, NMTB 35, NMTB 40, NMTB 45, NMTB 50, NMTB 55, and NMTB 60. The smallest tool holder (NMTB 25) normally goes on small machines, while the largest (NMTB 60) goes on larger ones. NMTB tool holders is a national association that focuses on building machine tooling systems such as the NMTB shank and spindle and other tooling systems.

Unlike other tooling systems, NMTB tool holders have a drawer. As single-flanged tool holders, there are two keyways that go onto a simple flange. Although NMTB tool holders are relatively old, they still fit into modern machining systems. Numerous manufacturers make these tool holders, making it difficult to have uniform dimensions for all NMTB tools.

In most cases, the flange thickness, diameter, and length from the taper’s gage line do not determine the dimensions of the NMTB tools. NMTB tool holders are manufactured in such a way that most of their tooling system is compatible with other tooling systems, like Erickson Quick Change Spindle.

Aside from that one, other brands are also compatible with NMTB tooling system. In most cases, users are advised to find out more about the tool before making a decision. NMTB tool holders can fit into other tooling systems of the same dimension by simply changing out the lug bars. For instance, users can do tool-changing operations by fitting NMBT 30 into Cat 30 or BT 30.                                        

NMBT Face Tool Holders

These holders are designed with an Arbor Screw Key and four mounting holes.

Some of its specifications are:

 Gage length of 2.25 inches. • Flange diameter of 4 7/8 inches.  • Four mounting holes.   • A bolt size of four inches.

More NMBT face tool holders are available and the specifications are dependent on the user’s choice.

NMBT Shank

These tooling systems have drive keys and arbor screw. They can fit into Erickson Quick-Change holders and their main use is as adaptors.

The sizes and dimension of these shanks vary, making them suitable for various machining operations. NMTB tooling is mainly for high-speed machining operations and high-precision tolerance. End-users will find them useful as they’ll be able to complete their projects with high accuracy. One fascinating feature of NMTB tooling technology is in its compatibility with other quick change spindles:

NMTB Compatibility with other Quick Change Spindles

NMTB tooling systems are highly compatible with other tooling machines. But the thing is that each tool holder has to have an appropriate and corresponding quick change spindle of the same dimension. That is, NMTB 30 can fit into Cat 30 and BT 30 tool holders. NMTB 40 and NMTB 50 will fit into Cat 40 and Cat 50 respectively.

In the original NMTB shank design, a drawbar pulls up the shank into the spindle. As we said, there are different manufacturers of these tooling systems and the flange diameter, thickness, and the distance of its taper’s gage line to the flange’s outward face do not determine its dimensions. The Erickson Quick-Change spindle by Erickson Tool was designed to be compatible with NMTB tool holders. Erickson Quick Change’s design is such that you do not use the drawbacks. Instead, you use quarter turn lockouts to fit the tool taper into the spindle.

For this tooling setup to work, the tool flange’s outer face comes out of the projection, or “lips”, at the nut. In some cases, the NMTB tool holders don’t work with Erickson Quick-Change spindle due to the distance between the flange’s outer face and the taper gage line. This gage distance is large, making it difficult for the projection or “lips” of the quick change to fit into the flange’s face. Other issues occur when the flange diameter on some NMTB holders is too small and unable to fit into the mouth of the spindle.

Overcoming these issues involves a thorough examination of the NMTB tool holders and spindles. This is to ensure that the specifications by the manufacturers match. Generally, the Erickson Spindles works well with NMTB tool holders. Other brands that work well include Collis, Valenite, and Kennametal holders.

What Next?

Performing high-speed machining operations requires great precision and accuracy. Ultimately, you’ll need a tool holder that’s for the modern day world but is also compatible with other quick change spindles. NMTB holders offer great value for users aiming to complete their projects with near-PERFECT precision and accuracy. These amazing tool holders are manufactured with top notch designs and come in diverse sizes. Are you searching for tool holders for your professional or DIY projects? NMBT tool holders are there to serve your needs.

Introduction to Shrink Fit Tooling

Shrink fit tooling is the leading choice for any high-speed machining operations. Although some argue that Collect Toolholder are better options, the reality still remainsL Shrink Fit tool holders are the best tooling technology for high accuracy and top speed machining.

Shrink Fit Tooling Machine

With amazing features, such as outstanding grip power, excellent balance, and good indicator reading, shrink fit tooling will help you get more work done in less time.
Using the shrink fit tool holder will create a positive impact on your work as you’ll get high precision in all your projects, increase the lifespan of your tool and spindle, reduce the tool change time, and lower the cost of tool maintenance.
In fact, shrink fit tooling enables you to create, build, and design customizable holders for all applications. The flexibility and high accuracy of this tooling system are phenomenal.
In this article, we’ll unravel the working formula of shrink fit tooling systems.

How Shrink Fit Tooling Works

Shrink fit tooling technology utilizes heat-shrinking to clamp cutting tool shank in high-speed machining. This quick-change tool holding process in high-speed machining in highly efficient and it saves production time for the user.
This process is simple as the shank cutter tool is inserted into the shrink fit tool holder. The interior diameter of the shrink fit tool holder is a little smaller than the diameter of the shank cutting tool.

Working Mechanism

This interior bore of the tool holder expands with heat. As the bore grows to a sufficient size, the tool cutter automatically slides into the bore. At this point, cooling begins and the bore shrinks, exerting uniform pressure (about 10,000 lbs of force) on the surface of the cutting tool shank. This results in a tremendous gripping strength on the whole surface of the tool shank.

The reverse process happens when you remove the tool. Shrink fit tooling technology makes it possible to accomplish tool changes within seconds, which in turn improves productivity during high-speed machining.
Manufacturers find shrink fit tooling systems useful as they’re able to do more work by reducing the time they spend on changing tools. End-users, on the other hand, can utilize this amazing technology to greatly increase their productivity.

Heating Systems in Shrink Fit Tooling Technology

The three heating systems in shrink fit tooling technology are: open flame, induction heating, and hot air.

Induction heating makes use of high-frequency current that flows through a metal coil. Here, you insert the tool holder into the metal coil and a high-frequency eddy current heats it up as the temperature greatly increases.

People usually install infrared temperature sensors to monitor the tool holder’s temperature. This serves as a safety measure for the proper control of the tool holder’s temperature and regulating the current in the metal coil. Induction heating is the best heating system available in the market.
Like induction heating, open flame and hot air systems function by heating the surface of the tool holder. The difference lies in the degree to which heat goes to the holder.
Unlike induction heating, hot air and open flame heat the holder more slowly, leading to little temperature variations between the tool cutter and holder. These heating systems are relatively less expensive and more economical than induction heating ones.
The cooling system in shrink fit tooling systems could be air or liquid filled coolants. These two cooling systems typically function through a 20k to 50k shrink/unshrink cycles.

Shrink fit tooling systems’ features include:

Concentricity

The concentricity of the shrink fit tool is outstanding, as it is below three microns. You’re guaranteed 0.00012″ (3 microns) run-out at three times the diameter of the cutting tool. With this high concentricity, the tool cutter and holder function like a single piece. This high level of accuracy is repeatable for all operators.

Balance

In the absence of moving parts, shrink fit holders offer the best balance repeatability of all tool holding systems available. Shrink fit holders come with the highest accuracy and balance standards. Special designs are also available at a tolerance level of G 1.0 at 30,000 RPM. This provides higher feed rates, speeds, balanced chip loads, and better finishes.

Rigidity

The cutting tool has 360 degrees grip on multiple planes around the shank. This results in an extremely high gripping torque that prevents any irregular movement of the cutting tool during roughing or finishing operations. This, in turn, results in the reduction of scrapped pieces.

Tool life Extension

Shrink fit tooling technology extends tool life by over 100%. Their concentricity, gripping force, and balance help you increase productivity and ultimately extend tool life by a wide margin.
Do you want a long lasting tool? Shrink fit tooling technology is the best for your needs.

Extremely High-Speed Operation

Shrink fit tooling is the go-to for any high-speed machining operations. Their clamping force along with their superior system makes them the best choice for any high-speed machining operations.
Unlike mill and hydraulic chucks, shrink fit tooling offers extraordinary concentricity, making it outperform other brands in the market.

Benefits of Shrink Fit Tooling Technology

1. Superb accuracy.
2. High gripping torque.
3. Extension outlets that offer you diverse options with standard products.
4. Reduction in tool-changing time. This, in turn, leads to greater productivity.
5. Setup cleanliness, leading to cleaner bores and less contamination. This is because shrink fit tooling is a sealed system.
6. Outstanding coolant options, which both aid in cooling and in delivering fine finishing.
7. Cost reduction. The cost of tool changing is far lower if you use shrink fit tooling systems.
8. Availability. Shrink fit tooling systems are readily available and having one of them guarantees quick tool changing and greater productivity.

Conclusion

Although other tool holders are available in the market, shrink fit tooling makes it easier to change tools at a very fast pace, reducing tool changing time and increasing productivity.
As the most economical tool system, shrink fit tooling increases tool life, reduces cost, and ultimately helps manufacturers and end-users get more work done.
As a plant manager, shop owner, or manufacturer, shrink fit tooling will be the best investment you’ll make, guaranteeing you a boost in productivity.