Metric Bolt Head/Wrench Size

These values differ from the ISO standard.

* The DIN and JIS standards have been replaced by the ISO standard. However, the older DIN and JIS head sizes, shown here, are still commonly used.

** According to the standard unless 15mm heads are specificaly requested 16mm heads are supplied.

• ASME - American Society of Mechanical Engineers
• IFI - Industrial Fastener Institute
• ISO - International Organization for Standardization
• ANSI - American National Standards Institute
• DIN - Deutsches Institut fur Normung
• JIS - Japanese Industrial Standard