The standard covers both steel and brass screws intended for general-purpose applications. The most common configuration is a machine screw combined with one or two captive washers. Standard Specifications Material Carbon steel (Class 4.8), Stainless steel (A2), and Brass Head Type Pan Head (Small pan head is 5%–20% smaller than standard) Washer Types
The helical split lock washer provides constant tension to prevent the screw from loosening under mechanical stress.
Because washers are pre-assembled, they eliminate the need for manual assembly on the production line, significantly reducing labor costs and the risk of dropped or missing parts. jis b 1188 pdf
The standard specifies that the pan head's diameter and height are slightly smaller than a standard DIN or ISO pan head, making them ideal for compact electronics. Technical Benefits & Applications
Features both a helical split lock washer (for tension) and a flat washer (to protect the surface). The standard covers both steel and brass screws
Helical split lock washer, flat washer, or internal tooth washer
Typically M2 to M12, with M3, M4, M5, and M6 being most common Clear Zinc, Yellow Zinc, Black Zinc, and Nickel Plating Key Components & Variations Because washers are pre-assembled, they eliminate the need
Usually includes just a split lock washer or a flat washer.
The current version of the standard is , which superseded the 1995 version and its subsequent amendments.
These fasteners are staple components in the electronics, automotive, and appliance industries due to their reliability in high-vibration environments. Accessing the JIS B 1188 PDF
