Degrees Per Inch Calculator
Key Takeaways
- Degrees per inch depends on the bending radius of your bender
- Smaller radius benders produce more degrees per inch of travel
- Essential for segmented bends and custom angles
What Is Degrees Per Inch?
Degrees per inch (DPI) is a measurement that tells you how many degrees of bend are produced for each inch of conduit that travels through the bender shoe. Every bender has a specific bending radius that determines this value. Knowing the DPI for your bender allows you to make precise bends at any angle, not just the ones marked on the shoe.
The inverse, inches per degree, tells you how many inches of conduit travel are needed to produce one degree of bend. This is useful when calculating the spacing for segmented bends.
The Formula
Degrees per inch is derived from the relationship between a full circle (360 degrees) and the circumference of the bending circle:
DPI = 360 / (2 × π × radius)
Example: 1/2" EMT Bender
- Bender radius: 4 inches
- Circumference: 2 x 3.14159 x 4 = 25.13 inches
- DPI: 360 / 25.13 = 14.3 degrees per inch
- Inches per degree: 1 / 14.3 = 0.070 inches per degree
When to Use It
Degrees per inch is critical in several conduit bending scenarios:
- Segmented bends: When making a large-radius bend using multiple small bends, DPI determines the spacing between each segment
- Custom angles: When you need a bend that is not marked on your bender, DPI tells you exactly how far to push the conduit
- Verification: If your bends are consistently over or under the target angle, the actual DPI of your bender may differ from the specification
Frequently Asked Questions
What does degrees per inch mean in conduit bending?
Degrees per inch tells you how many degrees of bend are produced for each inch of conduit that passes through the bender shoe. It depends on the bending radius of your specific bender. A smaller radius produces more degrees per inch, while a larger radius produces fewer.
How is degrees per inch calculated?
Degrees per inch is calculated by dividing 360 by the circumference of the bending circle: DPI = 360 / (2 x pi x radius). For example, a bender with a 4-inch radius has a circumference of about 25.13 inches, so 360 / 25.13 = approximately 14.3 degrees per inch.
When do I need to know degrees per inch?
Degrees per inch is essential for segmented bends and when you need to make bends at angles that are not marked on your bender shoe. By knowing the DPI, you can calculate exactly how far to push the conduit through the bender to achieve any custom angle.