Many processing parameters during the process of garment production influence knitted garment quality. The penetration force required of the sewing needle is primarily based on friction occurring between sewing work piece and sewing needle.  The highest penetration force of the sewing needle occurs at the moment when the sewing needle penetrates the sewing material. Needle penetration force is one of the most important parameters affecting the quality of seams. Needle penetration forces which are too high causes damaged loops, known as ladders. Before selecting an appropriate needlepoint, it is necessary to determine sewing needle size because it greatly depends on the sewing thread used. Sewing thread plays an influential role in seam design because it should be stretchable since knitted fabric has elastic properties in the direction of rows and whales. The size of the needle eyelet and thread thickness should be mutually adjusted in order for the thread to pass through the eyelet with as little as friction as possible. A measuring instrument with special sensors was used for determining penetration forces of sewing needle. The data acquired with this instrument was saved on computer in software “Nemess 5.0.”