The standard specifies requirements for cross-recessed head screws with captive washers . These are often referred to as "Sems" screws, where a washer is permanently attached to the screw blank before the threads are rolled, preventing it from falling off. Quick Reference for JIS B 1188
Socket set screws specified in JIS B 1188 are typically made from steel, stainless steel, or other materials. The standard requires that the materials meet specific strength and corrosion resistance requirements. jis b 1188 pdf
Kenji wiped his hands on a rag that had seen better days. He stared at the disassembled diesel pump on the workbench, a complex puzzle of springs, gaskets, and casings. It was a piece of machinery from a different era, built when things were made to be repaired, not replaced. The standard requires that the materials meet specific
According to typical JIS B 1188 data sheets , the dimensions for a standard M4 screw include: : 4 mm Head Diameter (dk) : 7 mm Head Height (k) : 2.6 mm It was a piece of machinery from a
While the full official standard is usually a paid document available through official bodies like ANSI or Intertek Inform , you can access technical specification sheets and dimension tables for these screws via several manufacturer and supplier PDFs:
It does cover countersunk or low-profile hexalobular screws (those are covered by JIS B 1194 and JIS B 1195, respectively).