Odd Leg, Internal and External Callipers

Odd Leg, Internal and External Callipers

Odd Leg Callipers

Understanding Odd Leg Callipers

• Odd leg callipers are a type of measuring tool mainly used for marking out material.
• They are designed to scribe a line a set distance from the edge of a workpiece.
• The tool features two ‘legs’; one straight leg which remains against the edge of the material and one bent leg with a hardened scriber which marks the workpiece.

Key Features of Odd Leg Callipers

• The bent leg of the calliper has a slight curve to it (this is the ‘odd’ leg) and ends with a pointed scribing tool.
• The straight leg features a small, flat surface to facilitate firm placement against the edge of the workpiece.
• The bending of the odd leg ensures that the marking is parallel to the edge of the workpiece, while the straight leg comfortable to the edge.

Using Odd Leg Callipers

• To use odd leg callipers, the distance from the edge of the material to the line to be scribed is set by adjusting the legs’ separation.
• The straight leg is then placed against the edge of the workpiece and the tool is dragged along the surface, creating a scribed line.

Internal and External Callipers

Understanding Internal and External Callipers

• Internal and external callipers are used to measure the internal and external sizes of an object, respectively.
• These types of callipers use two retractable legs to take measurements.

Key Features of Internal and External Callipers

• Both types of callipers are very similar in appearance. The main distinction is in the shape of their legs.
• Internal callipers have curved, inwards facing points, enabling them to measure the internal dimensions of an opening.
• Conversely, external callipers have straight, outwards facing points for measuring external dimensions, such as the diameter of a round object.

Using Internal and External Callipers

• To use an internal calliper, place the legs inside the opening or hole and expand them until they touch the sides. The measurement can then be read off the calliper, or the tool can be compared to a ruler or vernier scale.
• To use an external calliper, close it around the exterior of the object to be measured. The legs should lightly touch the surface on either side.

Importance of Callipers

• Callipers are vital tools in design and technology for ensuring high standards of precision and accuracy.
• Correct use of these tools, paired with understanding their functionality is pivotal to achieve professional results in manufacturing or creation processes.