GB/T 2673-1986 Hexagon socket countersunk head screws

GB/T 2673-1986 Hexagon socket head countersunk screws GB/T2673-1986 standard download decompression password: www.bzxz.net

1 Introduction
National Standard of the People's Republic of China
Hexagon lobular socket countersunk head screws
Hexagon lobular socket countersunk head screws This standard specifies the hexagon lobular socket countersunk head screws with thread specifications of M6 to M20. 2 Reference standards
GR196-81 "Basic dimensions of ordinary threads (diameter 1~600mm)" GB197-81 "Tolerances and fits of ordinary threads (diameter 1355mm)" GB2-85 "Ends of external threaded parts of fasteners" GB5279-85 "Countersunk head screws-Head shape and measurement" GB3098.1-82 "Mechanical properties of fasteners-bolts, screws and studs"; GB3103.1-82 "Tolerances of fasteners-bolts, screws and nuts" GB5267-85 "Electroplating of threaded fasteners"; GB 5779.1-86 "Surface defects of fasteners-bolts, screws and studs-General requirements; GB6188--86 "Head shape for screws-T type" GB90-85 "Inspection, marking and packaging of fasteners". 3 Size
Convention
Compilation end
Especially the threaded part, the rod diameter is approximately equal to the middle diameter or equal to the major diameter of the thread: the end is in accordance with GB2-85.
National Bureau of Standards 19860117 issued
UDC621.882.2
GB2673-86
Replaced GB 2673-81
1986-10-01 implementation
Thread specification d
Theoretical value
Actual value
Hexagonal shape
Usually: ①Do not use the specifications in brackets as much as possible. ②Force-butterfly distance.
③The theoretical value of d is in accordance with GB5279-85. GB267386Www.bzxZ.net
③ Screws with nominal length above the dotted line are made of full thread [b--(k+α)]. (M14)
4 Technical conditions
Mechanical properties
Product grade
Surface treatment
Surface defects
Acceptance and packaging
Note: The maximum allowable hardness is IV255.
5 Marking
GB2673—86
GB 196--81, GB 197-81
GB 3098.182
GB3103.1--82
①Untreated;
③Passivated GB526785
GB 5779.1—B6
GE 90—85
Marking example of hexagon socket countersunk head screws with thread specification d=M6, nominal length=20mm, performance grade 4.8 and no surface treatment:
Screw GB267386-M6×20
Additional instructions:
This standard is proposed by the Ministry of Machinery Industry of the People's Republic of China and is under the jurisdiction of the Standardization Institute of the Ministry of Machinery Industry. This standard is funded by the Standardization Institute of the Ministry of Machinery Industry, and Shanghai Standard Parts Technology Research Institute, Shanghai Standard Parts Factory No. 4, and Shanghai Standard Parts Factory No. 5 participated in the drafting.
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