Design of Automotive Towing DevicesGh.L. Mogan, I.D. Buzdugan — Transilvania University of Brașov
AnnexAnnex.ST.05

Clearance hole dimensions for bolted joints (extract from STAS 8121/3-74)

Bolted joint drawing

Dimension values

Nominal thread diameter d [mm]Clearance hole diameter D [mm]
Fine seriesMedium seriesCoarse series
44.34.54.8
4.54.855.3
55.35.55.8
66.46.67
77.47.68
88.4910
1010.51112
12131415
14151617
16171819
18192021
20212224
22232426
24252628
27283032
30313335
33343638
36373942
39404245
42434548

Note. The medium-series values are the ones most often used in practice.