Lenovo ThinkPad T420si Hardware Maintenance Manual page 81

Step Screw (quantity)
1
M2 × 5 mm, flat-head, nylon-coated (2)
Note: Some models might have only two antenna cables.
Color Torque
Black 0.181 Nm
(1.85 kgfcm)
.
Chapter 8 Removing and replacing a FRU
75