1 Chemical composition test
Within a specified time,incoming nuts materials of grade 35CrMo shall be retest, and results must be in accordiance with TABLE 1.
TABLE 1-1 Chemical composition of nuts(mass fraction)) /%
TABLE 1-2 Permissible tolerances for Chemical composition tolerances/%
1.2 Appearance inspection
Visual inspection and rule measurement shall be used to inspect surface discontinuities of nuts, and results must be in accordiance with TABLE 2.
TBALE 2 Surface discontinuities of nuts
|Nuts grade||Standard||Voids||Quench cracks||Seams||Forging cracks||Folds|
|810||GB/T5779.2-2000||≤0.25mm||not be permitted||≤0.05D||≤0.05Dnot more than two forging cracks||permitted|
D——nominal thread diameter
1.3 Dimension and tolerances inspection
Dimension and tolerance inspection shall be in accordiance with GB/T6170-2000 “Hexagon regulat nuts(style 1)”. See Table 3 thickness m is symboled and described.
Table 3 Thickness of nuts
|Specification of nuts||M30||M36||M42||M48||M56||M64|
1.4 Manufacturing method of nuts
Nuts are forged from hot-rolled steel round bars, internal thread machined by screw tap.
1.5 Cone proof load inspection
Cone proof load test on nuts shall be calculated by As(stress area)×Sp(stress under proof load). Sp numerical value of grade 10 style 1 nuts shall be 1060N/mm².
1.6 Hardness inspection
Hardness of nuts, nominal stress area in thread and cone proof load of threads shall be in accordiance with Table 4,
Table 4 Property of nuts
|Spc.||cone proof load KN||Hardness||Nominal stress area in thread mm2|
Our manufacture have the most advanced facility of heat treatment, with experienced experts and service teams.
Main products : anchor cage, anchor bolts, template, anchor plate, connect plate, gasket, threaded bars, screwed bars for Wind turbine wind tower foundation, studs, nuts, washers, rock bolts, heat treating round bars, heat treated stirrup, seamless tubes.
Anyang Longteng Heat Treatment Material Co.,Ltd
Add: Industrial Park, Indu District, Anyang City, Henan Province, P.R.C.
Email: [email protected]
Post time: Sep-12-2018