Detail & Specs
SEMS Double Washer Pan Head Screw / 4.8 Steel
JIS metric phillips pan head SEMS screws have a small head diameter and a set of captive (permanently attached) washers.
Length is measured from underneath the head, including the washers
Short for assemblies type screws
The washers on this SEMS screw are free spinning. Underneath the pan head is a helical split lock washer, beneath the lock washer is a flat washer. This double washer screw is common in the electronics industry but can be used in automotive, energy, agriculture, etc.
SEMS screws are beneficial for a variety of reasons: saving time by eliminating assembly of individual components, reducing loss of loose parts during assembly and compatibility with automated production equipment.
JIS B-1188 / Japanese Industrial Standard
The head height and head diameter of this JIS pan head screw is roughly 10-13% smaller than a standard pan head machine screw. Machine thread screws can be used in a tapped hole or with a locking / non-locking nut.
Yellow Zinc plated finish provides corrosion resistance