Thread thickness is the diameter of surgical suture material.

In addition to the knot, thread strength is decisive for the durability of a surgical seam. It depends on the material used and the thickness of the thread. As a general rule, the suture material must ensure a sufficient tear resistance and is chosen as thinly as possible in order to keep the tissue damage to a minimum. In the case of absorbable suture material, the thickness also has an influence on the dissolution process to be provided by the body or its duration.

The thread thickness printed on a packaging is always the minimum thickness. In most cases, the actual thread thickness is slightly higher, but below the upper range limit. Two different measuring systems are used to indicate the thread thickness,

The American system and the metric European system which measures in tenths of a millimeter.