The diameter of a suture is one of the criteria involved in its selection, and applies both to the needle and the thread.
The diameter, or gauge, is expressed differently depending on the reference pharmacopoeia (EP or USP).
There is a broad spectrum of diameters available.
The thread gauge used in ophthalmic – or plastic surgery cannot be used for sternal closure surgery, for example.
That is why the B. Braun range of sutures offers thread gauges from USP 11/0 to USP 4, to cover the different surgical disciplines.

This term designates the capacity of a material to be deformed without breaking.
Such a material is said to be ductile.
Ductile is the opposite of fragile or brittle, which defines a lack of bending strength and the resultant potential breakage of a material.
It is a property that is essential for surgical needles.
B. Braun surgical needles are made from a 300 stainless steel alloy for ductility and bending strength, allowing high reliability.