Traditionally, nuts without washers and serrated heads tend to loosen out of the intensity from the vibrations.  The regular nuts and bolts will never replace the flange nut because it is unique in its specifications and uses. The flange nuts can withstand the vibrations from machinery which it is being placed upon, considering it was built for that purpose.

This article will share insights and knowledge about flange nuts, starting from what flange nut is, how it is measured, the types of flange nuts, etc. We hope to answer the questions in your mind about flange nuts and further explain the functions.

flange nuts

What is a flange nut?

Flange nuts are also known as Hex Flange nuts because their six sides qualify them as a Hexagon. It has a wide flat head that serves as a washer. Hence, it helps to spread load placed on the nuts on a wider surface area. It prevents the machinery from damage. In essence, they are commonly used on automobiles because of the automobiles' constant movement and vibrations. On the other hand, the washer creates more grip to clamp the object on what the nut fastens-commonly made with carbon steel with a zinc coating finish to resist corrosion. However, materials like stainless steel, titanium, and brass are inclusive. They have specifications of DIN 6923, DIN EN 1661 ISO 4161.The nut's flange area may have slight grooves or serrations in the bottom that are designed to provide additional strength to the fastener's locking power. A metric flange nut is more resistant to loosening itself due to vibration, shock, and thermal stress. This makes them desirable for use in automobile and other high demand applications.For more on Hex nuts, an article has been well put together for you. You can access it here.

Dimensions Of Flange Nuts

dimensions of flange nuts
  • Nominal size which are in 2,4,6,8,10,12,16.
  • The diameter of the thread.
  • Width across flats.
  • The diameter of the flange.
  • The thickness of hex nuts.
  • The Wrenching length.
  • The flange thickness.

How To Measure A Flange Nut

  1. Place the end of the measuring tape on one of the flat sides of the nuts outer perimeter.
  2. Stretch the tape, then measure across the nuts' diameter to the flat-side directly across the one you are pulling from.
  3. Count the number of lines on the tape, measure to find the measurement and specifications.
  4. If you count 9 lines, the size is 9-mm (millimeters)  

Types Of Flange Nuts

  1. Non-serrated locknuts.
  2. Serrated locknuts.

Non-serrated locknuts

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Non-serrated flange nuts are hex nut with a non-spinning washer attached at the bottom. Underneath the washer is smooth underneath the flange and does not contain serrations. Used when the material has to be flat to the surface.

This nut will not dig into the mounting surface, causing a better continuity between the two surfaces. We carry non-serrated flange nuts in metric and inch. In metric, we carry them per DIN 6923 (standard non-serrated flange lock nut) and DIN6927 (flange top lock nut).

Advantages Of Non-serrated Locknuts

  1. These locknuts are best suitable for industrial applications, including truck manufacturing equipment.
  2. It works on smooth surfaces.
  3. Nuts are reusable for a limited number of times; the prevailing torque declines each time used.
  4. Adjusted and removed after installation.
  5. Used on smooth surfaces, painted surfaces, and matted surfaces.

Disadvantages Of Non-serrated Locknuts

  1. Re-used a limited number of times.
  2. Considered not suitable for long threaded assemblies because when the nut travels along the threads.
  3. Damages the locking features of the thread.

Serrated locknuts

These are locknut with ridges that holds firm into the surface it is tightened against, and it provides more resistance to vibrations. It is Also called serrated face locknuts, spin locknuts, and whiz locknuts.

These locknuts are best suitable for commercial and industrial applications.However, the manufacturers serrate the bearing surface of that to create serrated flange nuts, allowing for a better grip on the joint's surface. In as much as the nut is tightened onto the joint, the mating surface is scored by those serrations, and a locking fit is achieved.

Serrated locknuts work well for oversized or irregularly shaped holes since the flange covers any discrepancies and serrations cover the entire bearing surface.

Advantages Of Serrated Flange Lock-nuts

  1. Found in the most common finishing.
  2. You can leave out washers when using this type of nut since the flange extends the bearing surface, and those serrations need direct contact with the mating surface.
  3. Re-used without limitation. Serrated flange lock-nuts provides the strength and resistance required.
  4. Serrated locknuts help improve the grip of the nuts to prevent loosening from vibration.
  5. Usually used with some metal sheets.
  6. Used on irregular and oversized holes without any hurdles because the protruding circular flange increases the nut's bearing surface.
  7. No need to use washers with serrated locknuts. This will help you save time and money on your application.
  8. It eliminates the possibility of wrong connections.

Disadvantages Of Serrated Flange lock-nuts

  1. The automobile risk of corrosion is high if painted or coated.
  2. It uses distortion to provide a tight fit.
  3. If moisture could be an issue in your application, consider using another locking nut that will not expose the mating surface to corrosion.

Applications Of Flange Nuts.

  1. In automotive parts, majorly used in conjunction with a mating bolt to hold multiple parts together.
  2. Construction sites and also on heavy industrial applications.
  3. Elevators and in joining metal and heavy aluminum sheets.
  4. Light poles and pipeline industries.
  5. Used in building sites also in applying wood and metal parts in the case of carpentry.
  6. Finally, in marine applications.

Key takeaways!

  • Flange nuts are those nuts that have replaced the traditional nuts and bolts. Its benefits are vast.
  • There are different types of flange nuts, including the non-serrated flange nuts and the serrated flange nuts. They seem alike, with just the serrated being the only difference, and their uses are different.
  • These nuts provide a locking action that may be serrated.  Therefore it can not function on the same surface, but they are firm on the different surfaces used.
  • These nuts are not limited to industrial trucks and automobiles. You can find flange nuts for your automobile.