The publication of the European Pharmacopoeia (Ph. Eur.) resulted in a standardization of the classification of threads and gauges of surgical suture material. The Ph. Eur. specifies a decimal classification and metric coding for the gauges. It quotes a thread diameter of 1/10 mm, so that the thread gauge of 3.5 has a diameter of 0,35 mm. The following table of the gauges gives a comparison of the metric and the USP gauge coding.

EP/Metric	USP	Diameter limits in mm	Diameter limits in mm Absorbable monofilaments
0.2	10–0	0,020–0,029	–
0.3	9–0	0,030–0,039	–
0.4	8–0	0,040–0,049	–
0.5	7–0	0,050–0,069	0,050–0,094
0.7	6–0	0,070–0,099	0,095–0,149
1	5–0	0,100–0,149	0,150–0,199
1.5	4–0	0,150–0,199	0,200–0,249
2	3–0	0,200–0,249	0,250–0,339
2.5	–	0,250–0,299	–
3	2–0	0,300–0,349	0,340–0,399
3.5	0	0,350–0,399	0,400–0,499
4	1	0,400–0,499	0,500–0,570
5	2	0,500–0,599	0,571–0,610
6	3+4	0,600–0,699	–
7	5	0,700–0,799	–
8	6	0,800–0,899	–