Final answer:
The exact fraction used for shrink on a 30 degree bend is dependent on context such as material type, thickness, and bending method, which is not provided in the question. Therefore, we cannot provide a specific fraction without additional information.
Step-by-step explanation:
The fraction used for shrink on a 30 degree bend is not provided within the context of the question.
Shrinks are calculations that are typically used in engineering, specifically pipefitting and metalworking, to determine the amount of material that needs to be compensated for when bending material at a specific angle to ensure the final product maintains the correct dimensions and angles.
Without more context, such as the type of material, the thickness of the material, and the method of bending, it is not possible to determine the exact shrink fraction for a 30 degree bend.
However, a common approach is to use a shrinkage chart or mathematical formulas tailored to the specific bending process and material properties.
For instance, in some cases, the shrinkage for a 30 degree bend might be calculated as a fraction of the circumference of a circle that represents the bend.
These calculations can become complex and generally require knowledge of the specific application and material characteristics.