Overview
ISO 4228:1986 - Spanners and wrenches - Spline drive ends for power socket wrenches - is an international standard that defines the geometry and dimensional requirements for involute spline drive ends used on power-driven socket wrenches. It covers both male and female end dimensions, giving manufacturers and users the measurements needed to ensure correct fit, engagement and interchangeability of spline-drive sockets and driving tools.
Key topics and technical requirements
- Involute spline geometry: Defines spline form used for transmitting torque in power socket wrenches.
- Male and female dimensions: Complete dimensional tables for nominal sizes (examples shown: sizes 4, 5, 5A and 6) including pitch diameter, major/minor diameters, tooth thickness, fillet radii and effective tooth dimensions.
- Pitch definition: The pitch p/ps notation in the tables specifies spline dimensions - the first value is the diametral pitch, the second is the stub pitch, which denotes (as a fractional part of an inch) the basic radial length of engagement above and below the pitch circle.
- Module (m): Expresses the number of units of pitch diameter per tooth in millimetres.
- Fit and engagement: Male ends must be made to fit female ends exactly to ensure correct length of engagement. Special care is required so that any locking device is not subjected to torsional or axial load during use.
- Tabulated data: Standard includes dimensions in both millimetres and inches for manufacturing and inspection use.
Practical applications
- Ensures interchangeability of power socket wrenches and sockets across manufacturers.
- Used in design and production of power-driven socket tools, impact sockets, and accessory drives for assembly lines.
- Critical for automotive, heavy equipment maintenance, manufacturing assembly, and industrial maintenance where reliable high-torque connections are required.
- Supports quality control and inspection processes by providing reference dimensions for tolerance checks and supplier qualification.
- Hand and power tool manufacturers and designers
- Socket and accessory producers
- Quality assurance and metrology laboratories
- Procurement/specification engineers and maintenance managers specifying tool interfaces
- Standards committees and technical writers documenting tool interfaces
Related standards
- Produced under ISO/TC 29 (Small tools); users should consult other ISO standards on hand and power tools for complementary requirements and the latest editions of referenced documents.
Keywords: ISO 4228, spline drive ends, power socket wrenches, involute splines, diametral pitch, stub pitch, module, socket dimensions, spanners and wrenches, tool interchangeability.
