求招

桔子

去查查IPC标准和自攻螺钉的国标,上面应该有

This Workmanship Standard

ANSI/IPC-A-610 Class 2 Standard
340 Notes:

Torque:
All devices, components and assemblies mounted with metal hardware (screws, nuts & bolts, etc) on PCB抯, including any devices or components mounted to heatsinks, will be tightened within the required torque ranges specified in Tables 1 to 3 The torque ranges are based on the material type and size of the hardware

All Nylon 6/6 hardware used in PCB applications will be tightened within the required torque range specified in Table 4 The torque ranges are based on the size of the hardware

In cases where metal and nylon hardware combinations are used, torque values will be based on the ratings for nylon ( Ref Table 4 )
TABLE 1 (Steel hardware, machine screws)

Screw size
in/lbf torque value range
Kgf-cm torque value range

#2-56
1-25 in-lbf
115-288 Kgf-cm

#4-40
3-5 in-lbf
345-576 Kgf-cm

#6-32
7-9 in-lbf
806-1036 Kgf-cm

#8-32
15-18 in-lbf
1728-2073 Kgf-cm

#10-32
27-30 in-lbf
3110-3456 Kgf-cm

1/4-20
62-65 in-lbf
7143-7488 Kgf-cm