Cart 0


Posted by Centaur Precision Tools on

Understanding Total Indicator Reading (T.I.R) and Its Importance in Machining

What is Runout?

Runout, also known as Total Indicator Reading (T.I.R), is a critical measure in the machining industry that indicates the deviation of a rotating tool or workpiece from its ideal axis of rotation. Essentially, it represents how much a tool or workpiece wobbles as it spins. This wobbling can be measured using a dial indicator, which precisely reads the displacement.

Importance of T.I.R in Machining and Collets

T.I.R is crucial for several reasons:

  1. Precision and Accuracy: High T.I.R values can lead to inaccuracies in machining operations. In precision machining, even the slightest deviation can result in parts that do not meet the required specifications, leading to wasted materials and increased production costs.
  2. Tool Life: Excessive runouts can cause uneven wear on cutting tools, reducing lifespan. Tools that wear out quickly must be replaced more often, increasing operational costs.
  3. Surface Finish: A high T.I.R. can adversely affect the surface finish of machined parts, leading to rough surfaces that may not meet the required quality standards.
  4. Machine Wear: Machines subjected to high T.I.R values can experience increased wear and tear, leading to more frequent maintenance and downtime.

Checking and Ensuring Proper Runout

There are several methods to check runout in machining:

  1. Dial Indicators: Attach a dial indicator to a stationary part of the machine and position the probe against the rotating tool or workpiece. You can rotate the tool or workpiece and observe the dial indicator's readings. The difference between the highest and lowest readings is the T.I.R.
  2. Test Bars: Place a precision test bar in the spindle or collet and measure the runout with a dial indicator. This helps check the spindle alignment and collet performance.
  3. Laser Measurement Systems: Advanced laser systems can provide highly accurate runout measurements, typically used in high-precision environments.

Why We Need Accurate T.I.R

Accuracy in T.I.R is essential for several reasons:

  1. Quality Control: Accurate runout measurements ensure that parts are produced within specified tolerances, maintaining high-quality standards.
  2. Cost Efficiency: Reducing runout minimizes material waste and tool wear, lowering production costs.
  3. Operational Efficiency: Consistent and accurate machining reduces machine downtime and increases overall productivity.

Definitions of T.I.R in Machining

  • Radial Runout: The measure of how much the diameter of a rotating tool or workpiece deviates from a perfect circle.
  • Axial Runout: The measure of how much the end of a rotating tool or workpiece deviates from a flat plane.
  • Face Runout: Similar to axial runout, it typically refers to the flatness of the face of a rotating component.

Centaur Precision Tools and Collets

At Centaur Precision Tools, our collets and tooling systems are designed to minimize T.I.R., ensuring the highest levels of accuracy and performance in machining operations. Our Universal AF collets are engineered with precision to provide secure and accurate tool clamping, reducing runout and enhancing the quality of machined parts.

By maintaining low T.I.R values, Centaur Precision Tools ensures that our customers achieve optimal results in their machining processes. This leads to better-quality parts, reduced operational costs, and extended tool life. Our commitment to precision and quality makes our collets and tools an essential choice for machinists and engineers seeking reliable and accurate performance. 

#PrecisionMachining #RunoutReduction #TIRAccuracy #ColletPerformance #MachiningExcellence #ToolingPrecision #CentaurCollets #AccurateMachining #Metalworking #MachiningQuality


Understanding and controlling T.I.R. is essential for achieving high precision and efficiency in machining operations. High-quality collets and tooling systems like Centaur Precision Tools, machinists, and engineers can ensure low runout, leading to better part quality, reduced costs, and increased productivity.

Share this post

← Older Post