2. Draw an "x-y" axis on graph paper with the horizontal axis (abscissa, x-axis) labeled "s" and the vertical axis (ordinate, y-axis) labeled "t" or "t_CW" (CW for clockwise).

3. Plot points: X (s_x, -t_xy) and Y (s_y, t_xy). These represent the stresses on the x- and y-faces respectively, and the positive sense of the stresses are as we have always defined them:

4. Draw a line connecting X and Y. This will be the diameter of the Mohr's Circle.

5. Find center of Circle. This will occur where the line crosses the s-axis and marks the point (s_ave, 0)

6. Draw the Mohr's Circle with center at (s_ave, 0).

7. Mohr's Circle Details

• Where the circle intersects the s-axis defines the Principal Stresses. s_I is the Maximum Principal Stress and s_II is the Minimum Principal Stress.  
• The radius of the circle equals the Maximum Shear Stress, or half the difference of the Principal Stresses. R = t_max = (s_I - s_II)/2. t_max is the shear stress given by the top- and bottom-most coordinates of the circle.