1.     The area of a regular hexagon of side length  is given by 

2.     Area of a circle is πr2 (where r is the radius of circle)

3.     Area of cylinder = 2πrl (where l is the height of cylinder)

4.     The area each face of hex nut: area of hexagon – area of circular hole =  – π32 = 65.26

5.     The area of each side: 2mm x 6mm = 12 square mm

6.     The area of cylindrical inner hole = 2*π*3*2 = 37.7

7.     Therefore the total surface area = (2 x area of face) + (6 x area of each side) + (area of cylindrical inner hole)

= 130.5 sq mm + 72 sq mm + 37.7 sq mm =240.2 sq mm

8.     And the volume = Surface area x 2 mm = 480.4 cubic mm