Rotary Tacks / tack

It has been found that people tend to rotate the tack subconsciously when pushing the tack into solid surface such as wood board or wall.

With the aid of repeating experiments and data analyses, our subconscious experiance is based on scientific foundation. Flat tack has flat surface which lengthens the rotative radius,therefore,the arm of force is expanded. Also，the movement of rotation reduce friction force. As a result, flat tack is easier to be inserted.