Comparison : Item # WEM WM417040, .040 x 7" Pure Ground Tungsten
Item # WEM WM417116, 1/16 x 7" Pure Ground Tungsten
Item # WEM WM41718, 1/8 x 7" Pure Ground Tungsten
Item # WEM WM417332, 3/32 x 7" Pure Ground Tungsten
Item # WEM WM433332, 3/32 x 3" 2% Thoriated Ground Tungsten