Jis B 1188 Pdf Jun 2026
: Combines both plain and spring washers for maximum security. Size Range
: Often cited as a more cost-effective choice compared to patented conical washer alternatives. Cons :
It is worth noting that on , the Japanese Industrial Standards (Japanese Industrial Standards) were officially renamed to Japanese Industrial Standards (Nihon Sangyō Kikaku) . However, the technical content of the standards remains unchanged.
: Cross-recessed pan head screw paired with a serrated external-tooth lock washer .
Specifically, this standard covers the dimensions, tolerances, and technical requirements for slotted (flat-blade drive) screws that are not intended for high-strength structural applications. The typical products under JIS B 1188 include: jis b 1188 pdf
: Carbon steel grades for standard mechanical applications.
Ensures that washers are never forgotten in critical assemblies.
In standard manufacturing processes, putting a washer onto a screw manually during assembly is time-consuming and prone to human error (such as forgetting the washer entirely). JIS B 1188 outlines the parameters for screws where the washer is placed onto the screw blank before the threads are rolled. Once the threads are rolled, the outer diameter of the thread becomes larger than the inner hole of the washer, permanently trapping the washer on the screw. The Anatomy of a SEMS Screw (JIS B 1188)
The standard outlines the testing methods for socket set screws, including: : Combines both plain and spring washers for
: Slightly deeper heads with a larger undercut area.
Used heavily in dashboards, electrical wire harnesses, brackets, and non-structural engine bay components.
Due to the strict quality control enforced by Japanese Industrial Standards, JIS B 1188 fasteners are widely utilized globally across multiple technical industries:
The screws covered by JIS B 1188 are often referred to as —a term derived from "screw and washer assembly." The standard defines a manufacturing process where the washer is mounted onto the screw blank before the threads are rolled, making the washer permanently captive. However, the technical content of the standards remains
Preferred in computers, game consoles, and audio equipment due to the compact profile of the M2–M4 size ranges.
JIS B 1188 screws are used extensively in the . Their design offers several distinct advantages, including:
One of the most critical aspects of the standard is its categorization of different types of captive washers. The standard classifies screws based on the combination of washers used, designated by "P" codes for non-ISO configurations. The most common types are as follows:
The JIS B 1188:2017 standard is structured to cover all critical aspects of captive washer screws. The table of contents includes 14 main sections covering everything from scope to packaging marks.
Before you rush to search for , it is critical to understand one major industry shift: In 2003, JIS B 1188 was revised to align with ISO 1207, ISO 2009, and ISO 2010. After this revision, many features of JIS B 1188 (such as head dimensions and thread lengths) became identical to their ISO counterparts, although some legacy JIS differences (like smaller head diameters) still appear in older drawings.
JIS B 1188 is often categorized into specific types based on the washer assembly: