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)) /%

Grade C Si Mn Cr Mo P S
35CrMo 0.32~0.40 0.17~0.37 0.40~0.70 0.80-1.10 0.15-0.25 ≤0.035 ≤0.035


TABLE 1-2 Permissible tolerances for Chemical composition tolerances/%  


C Si Mn P、S Cr Mo
±0.02 ±0.02 ±0.03 +0.005–0.00 ±0.05 ±0.01


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
Pitch P 3.5 4 4.5 5 5.5 6
Q/AYLT 06-2016 THmm


max 31.5 38.5 42.0 47.0 56.0 63.0
min 30.0 37.0 38.0 45.5 54.0 61.0

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
Gr. 8级 Gr.10级 Gr.8 Gr.10
M30 538.56 594.66 HV233-353







M36 784.32 866.02 817
M39 936.96 1034.56 976
M42 1075.2 1187.20 1120
M48 1411.2 1558.20 1470
M56 1948.8 2151.80 2030
M64 2572.8 2840.80 2680
washers HRC 35.0-45.0



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.

TEL:  +86-372-2256782

Email: [email protected]







Post time: Sep-12-2018