Question

For an ASTM grain size of 8 , approximately how many grains would there be per square inch under without any magnifications.

A. 1,280,000 grains/in2
B. 640,000 grains/in2
C. 320,000 grains/in2
D. None of the above
For an ASTM grain size of 8 , approximately how many grains would there be per square inch under at a magnification of 100X.
A. 64 grains/in2
B. 32 grains/in2
C. 16 grains/in2
D. 128 grains/in2

Answer 1

An ASTM grain size of 8 corresponds to approximately 320,000 grains per square inch without magnification. At a magnification of 100X, an ASTM grain size of 8 would correspond to around 16 grains per square inch.

Step-by-step explanation:

The ASTM grain size scale is used to specify the size of grains in metals. The higher the ASTM grain size number, the smaller the grains. According to the ASTM grain size chart, an ASTM grain size of 8 corresponds to approximately 320,000 grains per square inch without any magnifications. This means that if you were to examine a square inch of the material without any magnification, you would expect to find around 320,000 grains.

When using a magnification of 100X, the grains would appear larger, so there would be fewer grains per square inch. Based on the ASTM grain size chart, at a magnification of 100X, an ASTM grain size of 8 would correspond to approximately 16 grains per square inch. This means that with the magnification, you would only see around 16 distinct grains within a square inch of the material.