DIN934 black nut vs. JIS B 1181 before year 1964: similarities and differences

In the industry and construction industry Bolt heads are considered very important fastening equipment. But in Thailand, many people may wonder between What is the difference between a "white zinc plated metric black nut (DIN934)" and a "white metric nut (JIS B 1181: 1964)"? Because from the appearance they look the same. Today we will answer the question.


Different production standards:

• "Black metrics white zinc plated nut" produced according to German standard DIN934 or Japanese standard JIS B 1181 (after 1964 until the present year)
  
• It is commonly used in industries all over the world.
  
• White zinc plated metrics nut manufactured according to JIS B 1181 (before year 1964)
  
• It's an old Japanese standard.
  
• It is still used in some industries.

Important Physical Differences

1. Thread Pitch

• Black metrics white zinc plated nut: has standard thread pitch according to DIN934.
  
• White metrics nut: Has a different thread pitch according to the old JIS standard.
  
• This difference may affect compatibility with other screws or nuts.
  
  

2. Size of Across Flat (AF) of the nut

• In some sizes, the two types of nut heads have different Across Flat (AF) sizes.
  
• Affects the choice of wrench or tool for tightening, such as a pneumatic block.
  

• Compatibility with other devices. Check the standards of the devices that will be used together.
• Consider the appropriate thread pitch.
• To check the size of wrench is required.
• Prepare tools appropriate to the bolt head size.