BS ISO 4251-1:2019

What is ISO 4251-1 - Code designated diagonal tyres about ? 

ISO 4251-1 is the first part of the multi-series standard that establishes the designation in use and the dimensions of code designated tyres in diagonal construction (ply rating marked series) for agricultural tractors, trailers and machines. 

Note: Code designated diagonal tyres (ply rating marked series) for construction applications (industrial tractors), identified by the classification code R-4, as specified in ISO 18805, or by suffix "IND" are covered by ISO 13442. 

Who is ISO 4251-1 - Code designated diagonal tyres for ? 

ISO 4251-1 on code designates diagonal tyres is relevant to: 

• Manufacturers of Tyres 
• Automobiles engineers 
• Mechanical engineers 
• Any entity responsible for testing and quality assurance of tyres and rims 

Why should you use ISO 4251-1 - Code designated diagonal tyres for ? 

In diagonal tyres, layers of nylon cord are positioned diagonally across each other in the tread and the sidewalls at an angle of 55 degrees. 

ISO 4251-1 specifies methods and guidelines for the manufacture of tyres with standardized dimensions and quality standards and defines standard markings for tyres and the tyre size designation for agricultural machines capable of carrying heavy loads. 

Overall, ISO 4251-1 is a comprehensive guide for the manufacture of diagonal tyres that lays out the requirements and dimensions so that users can improve the quality of tyres and make them according to standardized markings. This ensures that they can carry heavy loads and be used on any terrain. 

What’s changed since the last update ? 

BS ISO 4251-1:2019 supersedes BS ISO 4251-1:2017, which is withdrawn and includes: 

• Information already contained in other International Standards was removed and replaced with normative references to those standards 
• Radial tyres marked with ply rating and with a reference speed of 10 km/h were deleted since obsolete and this document was restricted to code designated diagonal tyres (marked with PR) for agricultural tractors, trailers and machines 
• The document was aligned with other International Standards developed by SC 5 and with existing regulations 
• Additional definitions useful for the comprehension of this document were added 
• Specific markings for tractor steering wheel and implement tyres and the pictogram to identify the maximum pressure for the tyre bead seating, as specified by UN/ECE Regulation 106, were introduced 
• Dimensional data and the list of approved rim contours were revised