Combination Set: Parts and Uses

what is combination set ?

A combination set, in the context of metrology, refers to a collection of precision measuring instruments and tools that are combined together to perform various measurement tasks and marking out. These sets typically include a range of instruments that work in conjunction to achieve accurate and reliable measurements.

Combination sets are designed to provide versatility and flexibility in metrological applications by offering a comprehensive solution for different measurement requirements. The instruments included in a combination set are carefully selected and coordinated to ensure compatibility and complementarity in their functionalities.

Commonly included instruments in a combination set may consist of gauge blocks, dial indicators, micrometers, calipers, height gauges, thread gauges, surface plates, and other specialized measuring tools. Each instrument serves a specific purpose and collectively enables the user to measure dimensions, distances, angles, threads, surface characteristics, and other metrological parameters.

By having a combination set, metrologists and engineers can have a range of tools readily available to accurately measure and inspect various components, ensuring compliance with desired specifications and standards. These sets are essential in industries such as manufacturing, quality control, research and development, and any field where precise measurements are critical for ensuring accuracy and reliability.

Must Read : Try Square

combination set square

A combination square is a versatile measuring and marking tool extensively utilized in metalworking, woodworking, and stonemasonry. It comprises a rule and interchangeable heads that can be attached to the rule. It is also known by various names such as adjustable square, combo square, and sliding square.

The standard head is the most commonly used attachment, serving as a square for marking and testing 90° and 45° angles. It provides the fundamental functionality of the combination square. In addition to the standard head, there are other types of heads available, including the protractor head and the center finder head. These additional heads expand the capabilities of the combination square for measuring and marking different angles and locating centers accurately.

Overall, the combination square is a versatile tool that offers a range of applications, enabling precise measurements and markings in various trades and industries. It is highly valued for its adaptability and accuracy in determining angles and achieving precise layout work.

combination set parts

Combination set parts

The combination set you are referring to consists of four main parts that work together to provide a versatile and comprehensive measuring solution:

1. Steel Rule: A steel rule is a measuring tool typically made of stainless steel. It is a straight, flat ruler with markings along its length for precise measurements of distances or dimensions. The steel rule provides a reliable reference for length-based measurements.

The steel rule in the combination set has versatile applications as it can be fitted into the center head, protractor head, or square head for specific measurement tasks. Alternatively, it can also be used independently as a straight edge or for general measurements.

In a metric combination set, the graduations on the steel rule are typically marked in millimeters or half-millimeter increments. These markings allow for precise and accurate measurements in the metric system, providing a reliable reference for length-based measurements.

2. Square Head: The square head is an attachment that can be fitted onto the steel rule. It consists of a right-angle measuring face perpendicular to the steel rule. The square head enables accurate measurement and marking of 90-degree angles. It ensures perpendicularity and helps maintain precise right angles in various applications, such as carpentry, machining, and fabrication.

3. Protractor Head: The protractor head is another attachment that can be mounted onto the steel rule. It includes a protractor scale with degree markings. The protractor head expands the functionality of the combination set by allowing measurements of angles other than 90 degrees. It enables precise angle measurements for tasks such as layout, design, and engineering.

4. Center Head: The center head is a specialized attachment used for finding the center of cylindrical objects or locating hole centers accurately. It typically has a pointed tip that aligns with the axis of rotation. The center head facilitates the precise determination of centers for hole drilling, turning operations, and other applications where accurate centering is essential.

By incorporating these four parts into a combination set, professionals in various fields, including woodworking, metalworking, engineering, and construction, can benefit from a comprehensive and versatile measuring toolset. This combination set enhances accuracy, efficiency, and consistency in measurements, allowing for precise and reliable results in a wide range of tasks and projects.

how to use combination set

To use a combination set effectively, follow these general steps:

  1. Familiarize yourself with the components: Understand the different parts of the combination set, including the scale, squaring head, protractor, and center head. Learn how each component functions and what measurements or markings they provide.
  2. Select the appropriate component: Determine which component of the combination set is best suited for your specific measurement task. Consider factors such as the type of measurement needed (length, angle, centering, etc.) and the features of the component that will facilitate accurate measurements.
  3. Set up the combination set: Position the scale on a flat surface and make sure it is stable. Attach the desired component, such as the squaring head, protractor, or center head, securely onto the scale. Use the locking mechanisms (bolts, nuts, or clamps) to ensure a stable and fixed position.
  4. Take measurements: Once the combination set is set up, use it to take the required measurements. For length measurements, align the object or material against the scale and read the measurement from the graduations. Adjust the sliding components, such as the squaring head or protractor, to achieve the desired angles or distances.
  5. Check for accuracy: After taking measurements, verify the accuracy of your readings. Ensure that the components are securely locked in place to maintain precision. Use additional tools, such as spirit levels or feeler gauges, if applicable, to check for parallelism or angle deviation.
  6. Make necessary adjustments: If adjustments are needed to achieve the desired measurements or angles, release the locking mechanisms and readjust the components as necessary. Take care to maintain stability and accuracy throughout the process.
  7. Record or mark measurements: Once you have obtained accurate measurements, record them or mark them on the workpiece or relevant documents. Use scribing points or other marking tools as needed for precise marking.
  8. Clean and store the combination set: After use, clean the components of the combination set to remove any dirt or debris. Store them in a dry and safe place, protecting them from potential damage or misalignment.

Remember to consult the manufacturer’s instructions and guidelines for specific usage instructions, as different combination sets may have slight variations in operation.

Precaution during Operating Combination Set

When operating a combination set, it is important to observe certain precautions to ensure accurate measurements and maintain the integrity of the tools. Here are some precautions to keep in mind:

  1. Handle with Care: Treat the combination set with care and avoid dropping or mishandling the tools. Rough handling can lead to damage or misalignment, affecting the accuracy of measurements.
  2. Clean and Dry: Before use, ensure that the combination set is clean and free from dust, dirt, or debris. Wipe the tools with a clean, dry cloth to remove any contaminants that could interfere with measurements.
  3. Avoid Excessive Force: When using the combination set, avoid applying excessive force or pressure, especially while taking measurements. Too much force can result in inaccurate readings or damage to the measuring instruments.
  4. Use Correct Attachments: When attaching different heads or accessories to the steel rule, ensure they are properly secured and aligned. Incorrect attachment or misalignment can lead to measurement errors and compromise the reliability of the combination set.
  5. Check for Wear or Damage: Regularly inspect the combination set for any signs of wear, damage, or deformation. Check the graduations, markings, and moving parts for accuracy and smooth operation. If any damage is found, it may be necessary to repair or replace the affected components.
  6. Store Properly: After use, store the combination set in a clean and dry place, protected from moisture, extreme temperatures, and direct sunlight. Proper storage helps to prevent damage and ensures the longevity of the tools.
  7. Calibration and Maintenance: Periodically check and calibrate the combination set according to manufacturer guidelines or industry standards. Routine maintenance and calibration help maintain the accuracy and reliability of the measuring instruments.

By following these precautions, you can ensure the proper operation and longevity of your combination set, enabling you to achieve accurate and precise measurements for various applications.

use of combination set

A combination set is a versatile tool that finds application in various fields and tasks. Here are some common uses of a combination set:

  1. Measuring Length and Distance: The scale in the combination set allows for precise measurements of length and distance. It can be used as a straight edge or ruler to measure the dimensions of objects or distances between points.
  2. Checking Right Angles: The squaring head attachment in the combination set helps in verifying and marking 90-degree angles. It ensures that corners or edges are perpendicular, which is essential in carpentry, woodworking, and fabrication.
  3. Determining Angles: The protractor attachment enables the measurement and marking of angles. It is useful in layout work, engineering, and various projects that require specific angle settings.
  4. Centering Objects: The center head attachment assists in finding the center of cylindrical or round objects. It aids in accurately locating the center for drilling holes, turning operations, or any application where precise centering is necessary.
  5. Height and Depth Measurements: The combination set can be used to measure height and depth using the scale and squaring head. It allows for precise measurements of the vertical dimensions of objects or depths of grooves, recesses, or holes.
  6. Parallelism Checking: The spirit levels present in the squaring head and protractor head help in assessing the parallelism of surfaces or checking for levelness or inclination. This is useful in aligning components, setting up machinery, or ensuring proper positioning in construction or manufacturing.
  7. Layout and Marking: The combination set assists in accurate layout work, such as marking dovetails or other angled cuts. It provides a reference for marking lines, distances, angles, or other features on workpieces.
  8. Inspection and Quality Control: The combination set can be used in quality control processes to verify dimensions, angles, and parallelism of components or finished products. It helps ensure adherence to specifications and standards.

The use of a combination set varies across disciplines and tasks, making it a versatile tool in industries like woodworking, metalworking, construction, engineering, and quality control. Its precision and multiple functionalities make it valuable for accurate measurements, layout work, and maintaining standards in various applications.


The combination set consists of a scale, squaring head, protractor, and center head. The scale is a long, heavy ruler with a groove along its length. The sliding squaring head is fitted onto this groove. One side of the squaring head is always perpendicular to the scale and can be adjusted and locked in place using a bolt and nut. The squaring head also has a spirit level for checking parallelism of surfaces. There is an included angle attachment on the scale for laying out dovetails. A scribing point is inserted into the base of the squaring head for marking purposes. The squaring head and scale can be used for measuring height, depth, inside and outside squaring operations.

The center head attachment is used with the scale to find the center of a bar or object. To locate the center, the object is placed under the scale and against the sides of the center head. Three lines are drawn on the scale by rotating the object, and the intersection of these lines gives the center point of the object.

The protractor can slide along the scale and has a semi-circular disc graduated from 0 to 90 degrees on both sides of the center. It also has a spirit level for leveling surfaces or checking inclined planes. The protractor helps in setting the correct angle of the work and allows for checking the deviation of the work from that angle using a feeler gauge.

In simple terms, the combination set has a ruler with a sliding head that can be adjusted and locked in place. It also includes a center head for finding the center of an object and a protractor for measuring angles. The tools are used for various measuring and marking tasks, such as height and depth measurements, angle setting, and centering objects.

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