Answer:
-Do not touch the contacts or interconnects or pads on ( RAM/DIMM's, GPU / Graphic's Card's, CPU / Processor )
-Not being concerned or cautious about ESD
-Do not over torque / over tighten screws.
-Not giving yourself enough room to build
-Not using a magnetic tray when building
Do you have some examples?
R=D/T
130 = r x 11.75
R=130/11.75=11.06
11.06 MPH