What are BT CNC Spindle Tool Holders?
There are a multitude of different types and styles of tool holder and we have discussed this briefly before in our article entitled ‘What a
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PRECISION MACHINIST'S TOOL HOLDING
EMG Precision have specially selected a huge range of Tool Holding products including a massive choice of ultra-precision machiniing tool holders, collets and much more. Industrial quality and precision at affordable prices.
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PRECISION MACHINING TOOL HOLDERS
Industrial quality spindle tool holders for machinist's. Including a range of ultra-precision tool holders featuring 1 micron repeatability. A huge range of types and sizes available. All with FREE Delivery.
BT ER Ultra-Precision Tool Holders
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As little as 1 micron Runout
Up to G2.5 30000rpm
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Shop our huge range of Ultra Precision CNC Spindle Tool Holders including a variety of styles and collet types, including BT, HSK, CAT, SK, ISO with chuck types ER, SK, Face Mill Arbor's FMB, SLN Side Lock, Test Bars, Calibrators and many more CNC Spindle Tool Holders...
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What are CNC Milling / Routing Tool Holders?
WORLD CLASS PRECISION CNC TOOL HOLDERS ONLY AT EMG PRECISION
A Toolholder is a mechanical device that provides the vital, safe and precision interaction between the user’s choice of cutting tool and the spindle drive motor system. A Cutting Tool is mounted into the chosen type of tool holder and tightened using a variety of means dependant on the design of the tool holder. This must be completed safely and securely in order to reduce vibration and maximise the stability and rigidity required in order for the safe machining of precision cuts with clean surface finishes. It is recommended that a Tool Holder Tightening Fixture is used to aid this process.
All EMG Precision CNC Tool Holders are guaranteed to be of the highest quality surpassing AT3 taper standards giving you the confidence that our tool holders will fit perfectly with your CNC machine and be of the highest quality. Our VANTABLACK range of EMG Precision Tool Holders are guaranteed to be accurate to 1 micron runout making them the most accurate standard format tool holders in the CNC industry today. We have state of the art manufacturing equipment and use only the very best materials and processes to give the ultimate in reliable, affordable, precision CNC Tool Holders of the very best quality you can buy, all with free world wide delivery included.
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WORLD CLASS PRECISION CNC TOOL HOLDERS ONLY AT EMG PRECISION
EMG Precision stock a huge range of CNC Tool Holder formats to cover all of your CNC machining needs. In addition to our usual range, if you are a CNC machinist with a particular need for a bespoke made tool holder please send your requirements to sales@emgprecision and we are sure that we can accommodate your custom CNC tool holder needs.
EMG Precision's typical range of CNC Tool Holders includes a comprehensive selection of MAS403 BT Tool Holders including BT ER Collet Tool Holders, BT FMB Face Milling or Shell Mill Tool Holders, BT APU Drill Chuck Holders, BT SLN, Side Lock Tool Holders, BT SDC Slim Pull Collet style Tool Holders, BT SK, BT Morse Taper Adaptor Sleeves, Ultra Precision BT Test Bars with only 3 microns runout at 200mm and 300mm, 3-Point BT Calibrators and more being added all the time. EMG Precision stock most types of BT Tool Holder in sizes BT30, BT40 and BT50.
An extremely popular and professional series of Tool Holders is the HSK range. EMG Precision have an expert range of DIN69893 standard compliant, HSK Tool Holders and as with the BT range, we also have HSK Tool Holders featuring in the VANTABLACK range that are Ultra Precision with world class 1micron runout (0.001mm). Our HSK Tool Holders are available in a variety of models like HSK ER Collet, HSK FMB Face Mill (Shell Mill) Tool Holders, HSK APU Drill Chuck Holders, HSK SLN, Side Lock Tool Holders, HSK SDC Slim Pull Collet style Tool Holders, HSK SK, Ultra Precision HSK Test Bars with only 3 microns runout at 200mm and 300mm, 3-Point HSK Calibrators and more being added all the time. EMG Precision stock most types of HSK Tool Holder in sizes HSK25, HSK32,HSK40, HSK50, HSK63, HSK80, HSK100.
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What are HSK Tool Holdrs?
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CNC Tool Holder Types
What are HSK Tool Holders?
The HSK type of tool holder is a highly innovative design that originates from Germany, Europe where this cutting-edge technology is widely used. HSK is a German abbreviation or Abkürzung, and translates as ‘Hollow Taper Shank’. Unlike BT Tool Holders that feature a 7/24 comparatively long tapered shank, HSK Tools feature a short 1/10, hollow shank. We will go into this in a little more detail later but essentially it removes the need for a retention knob and allows for ultra-precision high speed machining.
The use of HSK Tool Holders has been growing significantly since 1993, when DIN (the German standardization organization) issued the HSK shank standard, DIN 69893, for the six forms of the design. Stock standard styles in Germany are considered as Form Type A and C. Some manufacturers product HSK Tool Holders that are to proprietary standards and they do not conform to any currently and widely recognised standard. Be careful when you purchase HSK Tool Holders that they meet the correct and official standards. All EMG Precision’s HSK Tool Holders meet the globally recognised DIN69893 standard. The United States and North America are increasingly adopting the use of HSK Tool Holders, recognising that there is a need for higher precision and higher machining speeds in order to be competitive in today’s demanding markets.
HSK Tool Holders do require a new approach to their use and storage in order to maintain their ultra-precision. The tolerance between the spindle receiver and the HSK taper itself can be as little as 1-2 microns. EMG Precision offer a range of VANTABLACK Ultra Precision HSK Tool Holders that offer less than 1 micron runout at G2.5 30,000rpm making them some of the most accurate tool holders available on the global market today.
Types of HSK Tool Holder
There are basically 3 types of application specific to HSK Tool Holders that cover a range of six different specific categories of tool holder that have varying features covered here:
Type A: These tool holders are designed for automatic tool changing and require moderate or high spindle speeds and moderate torque for maximum efficiency.
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Type B: Another automatic changing design, type B tool holders are perfect for high-torque applications that use high or moderate spindle speeds.
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Type C: Similar to type A, type C HSK tool holders are meant for manual changing with the same moderate torque and moderate-to-high speeds.
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Type D: These tool holders are the manual changing version of type B HSK holders.
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Types E and F: For low-torque applications that require extreme spindle speeds, choose either type E or type F tool holders.
It is necessary to correctly match the HSK Tool Holder type with the machine and application in order to obtain the sought after results. Improper use may cause damage to people, machine and equipment or simply not give you the correct precision machining results.
In comparison to conventional steel tapered shanks, an HSK tool holder allows much more control over precision at high speed due to its greatly increased radial stiffness over more traditional tool holders. The radial stiffness of an HSK Tool Holder can be as much as five times more than that of a typical BT, CAT or SK Tool Holder.
An HSK assembly also owes its rigidity to its simultaneous-fit design. This means the toolholder’s flange face contacts the spindle’s face at the same time the taper is completely drawn into position. Because the toolholder is 0.00635mm shorter than the spindle socket, an interference fit occurs at the toolholder’s flange face. The resulting axial force, or mechanical preload, between the flange face and the spindle ensures full contact of the mating surfaces. This increased bearing surface area gives HSK holders better resistance to radial deflection than standard-taper holders have.
What are BT Tool Holders?
We typically refer to two types of tools in the CNC Machining industry. There are the Cutting tools which seems pretty y obvious like parting tool or a bull nosed end mills, to name just a couple out of hundreds of types. Then we often refer to the components that hold these cutting tools, as tools also, more often than not though, they are referred to as Tool Holders. There are all sorts of other bits and bobs that may accompany these elements, such as, but not including shims, pull studs, set screws, specialist tightening tools and many other specialised elements that contribute to the assembly of Tool Holder and Cutting Tool. Obviously there are a million and one other types of tool used in CNC machining industries but nice times out of ten if someone is referring to a tool it will be about a cutting tool or tool holder.
There are a multitude of different types and styles of tool holder and we have discussed this briefly before in our article entitled ‘What are CNC Tool Holders’. For the purpose of this article, we will focus our attention on the JIS MAS403 BT Tool Holder Type. JIS stands for Japanese Industry Standard, whereby the format and fundamental design of this tool holder originated. BT spindle tool holders are very similar in appearance to CAT, and even SK tool holders due to the almost, full length, cone like feature that marries with the Spindle cone. The BT tool holder is secured to the spindle by the use of a pull stud (pictured) that is screwed into the top of the BT tool holder cone.
The similarities continue with the naming designation. In the same format as CAT tool holders BT tool holders are most commonly classified as BT30, BT40 and BT50. The increasing numerical value denotes an increase in tool holder and taper size. BT tool holders are typically balanced as standard to around 12,000rpm, but unlike CAT holders, BT feature a symmetrical design throughout the spindle centre axis. This means that BT Tool Holders can be used at higher speeds when specifically balanced by means of an additional refinement process after the original manufacture. This axis symmetry also means that BT spindle tooling, by its nature, has greater balance and stability at higher speeds as previously mentioned. This enables BT tool holders to be used throughout a range of speeds and feeds and improves cutting tool life, finish quality and machining precision.
Anatomy of a BT Spindle Tool Holder
Without going too deep into the history it is reasonable to say the CAT and BT Tool holders originated around the same time in a move to try and standardise tool holders due to its ever increasing use in industries where large billet machining was being increasingly more adopted typical fabrication routes. BT and CAT Tool holders share the same physical presence and functional intent, and are actually interchangeable in spindles if mounted to the spindle manually. The biggest difference lies in how the automatic tool change process occurs and the clamping method. It is not possible to use an automatic tool change system with BT Tool holders into a CAT spindle, and vice versa.
Just like HSK Tool Holders, BT tool holders come in numerous types and designs specific to a large range of functions. The common ER Collet cutting tool clamping method is very common with BT Tool Holders. The usual Face mill arbors are readily available and referred to as BT FMB when in metric sizes and FMA when measured in imperial. BT SLN CNC Tool Holders, often called Side Lock tool holders are also widely used, and are designed to secure the cutting tool with set screws.BT tool holders are also available as Morse Taper Sleeve adaptors, more flexible BT APU holders that are essentially like a 3-Jaw chuck with a BT taper connection for mating with a CNC spindle. There are many more types of BT tool holder and it is reasonable to say that if it can be imagined, it has probably been made for use with a BT standard connection. BT Tool holders are thus an extremely popular choice among system designs, although the popularity of HSK due to its superior performance has downgraded BT holders from the go-to choice.
As with all precision equipment it is necessary to keep BT Tool Holders, clean and free from surface damage and foreign contamination. If for example your part choice of tool holder is a BT ER Collet type, it is crucial to make sure that the cone surface and mating surfaces are free from swarf, oils and chips. The machinist has to ensure that the threads for the Pull Studs are kept clean and interference free. The threads for the collet nut and the collet and cutting tool itself must also be clean before assembly. Failure to adopt this best practice will almost certainly have negative effects on balance, Runout and ultimately machining precision and surface quality.
Given the wide array of BT Tool Holder types, their large availability and ability to have the right kind of tool type for most, if not all operations, BT Tool holders will be around for a long time to come yet.
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