Machining 09: What are tool holders?

Tool holders are defined by standards in terms of shape and size. There are BT, BBT, HSK, etc. for machining centers (MC), and CAPTO for lathes, turning centers (TC), and lathe-based multitasking machines.

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2-1. BT

BT stands for &#;bottle grip taper&#; and is marked by a tapered shank. It is used by attaching it to the spindle of an MC. The BT shank was originally developed in Japan and is widely used in manufacturing sites around the world.

The size of the taper is fixed and is a 7/24 taper, where the diameter is 7 mm smaller for 24 mm axial direction. Depending on the diameter length of the largest part of the taper, there are nominal numbers such as BT30, BT40, and BT50.

NT shanks with 24/7 taper are also utilized in milling machines and boring machines that do not have an automatic tool changer (ATC). NT stands for &#;National Taper&#;.

2-2. BBT

BBT shank is a standard developed independently by BIG DAISHOWA SEIKI, a Japanese leading tool holder manufacturer. It is difficult to distinguish the BBT shank from the BT shank at first sight, but the biggest difference is that BBT shanks are dual contact spindle system. &#;Dual contact&#; means that shank contact the spindle taper and spindle face simultaneously.

With the BT shank, only the tapered part is in close contact with the main spindle, and there is a gap between the shank end face and the end face of the main spindle. In this case, when the spindle rotates at high speed, the main spindle bore expands due to centrifugal force, causing the shank to be pulled into the spindle bore, which changes the position of the tool and may negatively affect machining accuracy, especially in the Z axis.

On the other hand, with a BBT shank, the shank end face and main spindle end face are in close contact, so the shank is not pulled into the spindle bore and machining can be performed with high accuracy even at high spindle speeds. Because the two surfaces are in close contact, the BBT shank is more rigid than the BT shank, and vibration during machining can be controlled. The BBT shank can also be used interchangeably with the BT shank, making it easy to use.

2-3. HSK

HSK is a shank standard for high-speed rotation developed in Germany. HSK stands for &#;Hohlschäfte-Kegel&#; in German, and means hollow shank tapers.

HSK shanks have a shorter overall holder length and a hollow internal structure that is lightweight in order to support high-speed spindle rotation. The size of the taper is fixed, and a 1/10 taper is adopted, where the diameter is 1 mm shorter for 10 mm in the axial direction. It offers high rigidity due to the dual contact system in which the end faces of the taper part and shank are in close contact with the main spindle. Shank sizes are also specified, with six main types used: 25, 32, 40, 50, 63, and 100. Smaller numbers indicate smaller shank sizes.

2-4. Polygonal taper interface with flange contact surface

&#;Polygonal taper interface with flange contact surface&#;, also well-known as Coromant Capto, is a standard for tool holders for lathes and TCs developed by Sandvik, a leading Swedish cutting tool manufacturer. It became an International Organization for Standardization (ISO) standard in and is widely used as a standard system for tool changing on lathes and TCs.

It is a polygonal shape with 1/20 taper and dihedral constraint, as with HSK and BBT. There are six sizes: C3, C4, C5, C6, C8, and C10. Smaller numbers indicate smaller sizes.

3. Major types of tool holders

Tool holders for MCs can majorly be categorized into 1) collet chucks, 2) shrink chucks, and 3) hydraulic chucks.

3-1. Collet chuck

Collet chucks are widely used in machining sites for their easy attachment of cutting tools with high tool gripping force. The tapered collet opens and closes to attach, detach, and fix the tools.

Collet chucks come in a variety of shapes and can grip cylindrical workpieces as well as tools. For this reason, there are cases where collet chucks are used on lathes.

There are two main types of collet chucks used as tool holders on MCs: &#;Push-out type&#; and &#;Draw-in type&#;.

With the push-out method, by turning the nut on the tip of the collet chuck and pushing the collet inside, the collet is closed, and the tool is firmly gripped.

With the draw-in method, by using the screw on the bottom of the collet to pull the collet inside, the collet is closed, and the tool is gripped tightly.

3-2. Shrink chuck

Shrink chucks are chucks that utilize the nature of metal, which expands when heated and shrinks when cooled, for gripping tools.

The process of how the shrink chuck works is as follows. At first, the tool holder is heated by a heating device. Then, the tool is inserted into the inner diameter of the shank, which has been expanded by heating. The tooling is then cooled with water or other coolant. The result is that the inner diameter of the shank shrinks and the tool is fixed. To do this process, a special heating device is required.

This method has higher rigidity and run-out accuracy than other tool holders, and is effective for machining of hard materials and high-precision machining using small-diameter tools. Because a dedicated heating device is utilized, it is not dependent on the skill level of the operator, and the high repeatability of attachment is also a key advantage of this method.

3-3. Hydraulic chuck

Hydraulic chucks use a cylinder that adjusts oil pressure with a screw to pressurize and grip tools. It is easy for anyone to grip a tool with a single hexagonal wrench. Hydraulic chucks have extremely high run-out accuracy and are often suited for finishing operations. In addition, oil has a high ability to absorb vibration energy and reduce the vibration generated during machining. However, compared to other types of chucks, such as collet chuck, there are some issues in terms of rigidity. Tool holder manufacturers are therefore working on the development of hydraulic chucks with improved rigidity.

3-4. Other tool holders

In addition to the three tool holders introduced above, there are many other types of tool holders for MC, such as arbors for attaching indexable milling tools, drill chucks for holding drills, tool holders used for tapping, boring bars for boring, etc.

One of the tool holders that increase the functionality of the MC&#;s main spindle is angle head. The angle head is a tool holder that changes the machining direction of the tool to a specific angle, which allows machining with one new axis added to the existing MC. As a result, by effectively utilizing the angle head, various machining operations can be performed with only one attachment of the workpiece to the table, improving machining efficiency.

The speed-increasing spindle is also a tool holder that boosts spindle performance. It is attached to the main spindle of an existing MC to increase the spindle speed. Even in fine machining, where high spindle speed is required, existing MCs can be operated with the speed-increasing spindles.

You&#;ve just invested in a CNC lathe and need to buy tool holders but don&#;t know where to start.

With so many different kinds of CNC tool holders on the market, how do you know which one is right for your machine?

ToolHoldernow is here to help. We offer various tool holders for CNC lathes, including BMT, VDI, static, and live tool holders.

Our experts are happy to help you learn more about tool holders. This blog lets you know the types of tool holders, their importance, and how to maintain them.

So, keep reading it.

Types Of CNC Tool Holders

The right tool holder can significantly improve your efficiency and precision on the job &#; consult a reputable China manufacturer to find the best fit for CNC lathes.

For more Types of Tool Holders in Cncinformation, please contact us. We will provide professional answers.

There are many kinds of tool blocks, and here are the types we offer:

BMT Tool Holders

BMT tool holders are commonly suitable for boring and facing operations. These have a cylindrical shank that fits into the spindle.

They offer a rigid connection between the cutting tools and the machine spindle. And they are generally used for heavy metalworking operations such as machining steel or aluminum.

VDI Tool Holders

VDI, or Verein Deutscher Werkzeugmaschinenfabriken, tool holders are used with CNC turning centers and feature an offset design that allows for more versatile machining capabilities. You can easily replace the different tooling during the machining process.

Static Tool Holders

Static tool holders provide a secure grip on the cutting tool while stationary. They are individually suitable for each turning center and are the highest precision.

Live Tool Holders

Live tool holders can rotate during machining operations to perform tasks such as drilling or tapping.

With many options available, working with experienced professionals is vital to determine the best solution for your CNC equipment and project requirements.

Toolholdernow is a professional China manufacturer of custom tool holders, and we can meet your various customer needs. So, please contact us.

Tool Holders For Different Brands Of Machines

Different brands of machines require different tool holders. Each tool holder is designed to work optimally with its corresponding machine, providing the best possible performance and results.

MAZAK tool holders

It is known for their high quality and durability. We offer a wide range of tool holders to meet the needs of different applications. MAZAK tool holders are made from high-strength materials and feature various innovative designs.

HAAS Tool Holders

HAAS tool holders provide the utmost precision, repeatability, and rigidity for your HAAS CNC lathes.

The features that set HAAS tool holders apart from other brands are its precision ground spindle taper, hardened steel locking mechanism, and high-strength retention knob.

OKUMA Tool Holders

OKUMA tool holders are designed to provide users with high accuracy and repeatability. They are available in a variety of sizes and styles. We can customize any size to meet the specific needs of each customer.

Proper Tool Holder Maintenance

For those working with CNC lathes, tool holder maintenance is an essential but often overlooked aspect of the job.

Tool holders can become damaged or worn without proper care, leading to inferior work and potentially hazardous situations.

So how to maintain tool holders?

• First, it&#;s essential to inspect them regularly for any signs of damage or wear.

• Second, properly tighten the clamping mechanism before each use to prevent slippage during operation.

• Next, clean them thoroughly after each use to remove any built-up debris or grime that may affect performance.

• Finally, store them properly in a cool, dry place to prevent corrosion.

By following these simple steps, you can ensure that your tool holders will perform at their best for years to come.

Don&#;t let improper maintenance result in costly mistakes &#; make sure to give your tool holders the attention they deserve.

What Is A CNC Lathe Tool Holder? And Its Importance

CNC lathe tool holders are devices used to hold and secure cutting tools in place during CNC lathing operations.

Not only do they ensure the proper alignment of the tool, but they also provide a stable platform for the cutting operation.

In addition, many CNC lathe tool holders have coolant systems and chip evacuators, ensuring maximum efficiency and safety during use.

CNC lathing operations would be impossible without these tool holders, making them an essential component of any CNC lathe setup.

Our Capabilities Of Machining Tool Holders

At Toolholdernow, we have the capacity and experience to produce high-quality tool holders for various machining applications.

With CNC milling and turning machines at our disposal, we can handle tool holders ranging from small and intricate to large and complex.

Our skilled machinists use precision measurement tools to ensure accurate dimensions, resulting in a tool holder that operates smoothly and efficiently.

In addition, we offer customizable options such as engraving and special coatings.

No matter the specific requirements, our clients can trust our capability to provide precisely what they need.

So when it comes to machining tool holders, look no further than Toolholdernow.

Conclusion

With this article, you may learn about different tool holders.

If you&#;re not sure which type of tool holder you need for your project, we can help.

We offer many tool holders for CNC lathes, Click our home page, and we&#;ll be happy to assist you in finding the right product for your needs. And we can help you choose the right tool holders.

For more information, please visit What Is Collet Size.