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  • BT Test Bar

  • BT Test Bar

  • BT Test Bar

  • BT Test Bar

BT Test Bar

The largest causes of excessive tool wear and breakage are machine tool spindle runout and excessive slop or axial play. The spindle runout test bar can test your CNC machine tools for precise accuracy and proper alignment. Test bars ensure a stable production environment and consistency when moving jobs from one machine to another.


Spindle Runout Testbars are easy to use and they fast way to verify your machine spindle is running properly. Check them after a machine crashes and take the proper steps to prevent unintentionally making scrap parts.

Products Description

A BT test bar, often referred to as a "BT tool holder" or "BT collet," is a type of tool holder used in CNC machining. The "BT" designation typically stands for "Bata" or "Big-Plus," which are specific standards for tool holder designs primarily used in Japan and some other regions.


BT Test Bar includes a sturdy aluminum case to protect and store test bar

Currently available in ISO40 taper (CT/BT/SK)

Other machine tapers coming soon

Pull stud included


BT Test Bar Specifications:


Runout accuracy: 0.003 mm

Roundness: 0.001 mm

Surface roughness: Ra 0.1 μm

Outer diameter tolerance: ±0.005 μm

Spindle test bars are for static use only. Do not operate the spindle with the test bar installed.

Can't find the spindle taper test bar of the right size? Contact us.


Benefits of BT Test Bar:


Identifies potential problems with spindles and bearings

Helps reduce machine downtime and costly repairs

Spindle test bars are a quick and easy way to verify the runout and alignment of your machine’s spindle after a crash, after the machine has been moved, or as a periodic performance check. Excessive runout and axial play in a machine tool spindle are the major causes of excessive tool wear and tool breakage. Use one of our high-precision spindle test bars to verify that your spindle is running accurately, to ensure consistent parts and a stable production environment.


Key Features of BT Test Bar:


● Precision: BT test bars are designed to hold cutting tools securely, providing high precision and rigidity during machining operations.

● Compatibility: They are compatible with various CNC machines and are often used in milling applications.

● Tool Changes: Quick tool change capabilities make them convenient for operations requiring frequent tool changes.

● Material: Typically made from high-quality steel to ensure durability and resistance to wear.

● Variability: Available in various sizes and configurations to suit different machining needs.


BT Test Bar Applications:


● CNC milling and drilling operations.

● Tool measurement and calibration.

● Testing tool offsets and runouts in precision machining.


Feel free to ask if you have specific questions or need more details about BT test bars!


Tags: BT30 Test Bar BT40 Test Bar BT50 Test Bar BT spindle test bar