Key Highlights
- Socket flanged button screws, also called flanged hex screws, provide a large contact area for a secure hold.
- Due to the built-in flange that acts like a washer, they distribute the clamping force evenly.
- They are suitable for applications requiring a low-profile head.
- You can easily install and remove them with a hex key, making them ideal for a wide range of applications.
- The integrated flange eliminates the need for a separate washer, streamlining the assembly process.
Introduction
Various industries use Socket Flanged Button Screws, also known as flange button head screws, as they are such versatile fasteners.
As a type of socket screw, they feature an inbuilt flange that provides a more even distribution of load compared to flange-less socket button screws.
They are typically made from stainless steel or steel and offer a good grip when tightened. With their unique flange design and socket head, these screws ensure a secure and stable connection. This makes them a popular choice in many different types of projects.
Manufacturers produce flanged socket buttons in imperial and metric sizes, but this post focuses only on the metric versions.
After reading this article you may want to scroll back up here and read a couple of related posts. The first one, socket screws : the ultimate guide to a screw with socket drills down into all the common types of socket screws and their differences. The second one, Your ultimate guide to socket button head screws ISO 7380-1 explores the other version of button head screws – minus the flange.
But first, let’s get into it and explore all about the flanged button!
Understanding the Basics of Socket Flanged Button Screws
If you were to look at flanged socket button head screws, the most obvious thing you would notice is the large diameter of the flange on the head of the screw. This flange is almost like an inbuilt washer on a standard button head screw.
The flange creates a larger contact area, evenly distributing the load on the fastened surface. This enhances the screw’s grip and protects the fastened material, particularly for materials prone to damage when a smaller diameter head screw is overtightened.
Characteristics of Socket Flange Button Head Screws
A key feature of socket flanged button head screws is their head size, it is large and low-profile, unlike most other screw types heads.
The flange has a large contact area, which helps spread out the load more evenly than regular socket button screws. This even distribution of load protects against warping or damaging softer materials when securing them.
Finally, socket button screws with a flange look clean and tidy. This makes them a popular option for projects where appearance is important, like in furniture, electronics, and car assembly.
Key Advantages of Socket Flanged Button Screws
One big plus of using socket flanged button screws is their built-in washer. This eliminates the need for a separate washer, though you can use a shake-proof washer, for extra grip if desired. Some people, when fastening a softer material will also use a penny repair washer to further spread the load when tightening.
Since you tighten them with an Allen key / hex key they are ideal for use where there may be restricted access above the head. You can use a ball ended hex key to offset the angle at which you are driving them. Or you can flip the key around and use the short arm as not much clearance is needed.
Typically, you would screw these into a pre-threaded hole but you could also use them with a nut and washer on the other end if needed. The choice would depend on what your application requires.
Their low-profile and rounded head design helps reduce any snags, offering an ideal finish where a more prominently raised head screw might cause problems.
Common Uses of Flange Button Head
As i mentioned above, flange button head screws are ideal to spread the load on softer materials due to the large outer diameter of the head. You can also use them with a large repair washer to further distribute the load.
Another common use is for covering unsightly gaps or holes that a normal screw head would not cover.
It is not uncommon for automotive manufacturers to use hex socket flange button head screws while building their vehicles. Common uses would be on engine parts and panels.
Many manufacturers use them on machines to secure panels, housings, or guards in place. Or they might also use them to cover elongated holes in slotted adjustments.
Furniture manufacturers also use them for various reasons like some mentioned above as well as the fact that they are low profile and are not likely to cause any significant, if any snagging.
Difference Between ISO 7380-2 and ISO 7380-1
The ISO 7380 standard outlines the details for hex socket button head screws. There are two types of screws under this standard: ISO 7380-1 and ISO 7380-2.
ISO 7380-2 refers to the flanged version of the two and ISO 7380-1 refers to the standard socket button head.
It may be worth noting that both types have the same head height and both take the same size of Allen key, the main difference between the 2 is the added flange.
While the standard button head may look a little better on a job that needs a good finish, the flanged version takes a little of the looks and adds in the benefits of that added outer diameter.
Common Materials Used to Produce ISO 7380-2 Flange Button
ISO 7380-2 flange button head screws come in different materials for different uses. Some common options include stainless steel, zinc-plated steel, and self colour steel.
A2 stainless steel is an excellent everyday material for flange button head screws and withstands the UK weather effectively. If however, you would be using them near the coast or in a marine environment you would be best to opt for A4 (316 stainless steel) due to its higher corrosion resistance.
Another common choice is zinc-plated steel, which provides some rust resistance but is not well-suited for extended outdoor use. Or, there is self-color steel, which offers no corrosion protection and is best reserved for indoor use or situations where corrosion is not a concern. Both of these usually come in 10.9 grade and are classed as high tensile.
Understanding The Specifications of Socket Flanged Button Screws
Flange button head screws are made to the exacting standards of ISO 7380-2 which are defined by the International Organization for Standardization. Then the threads are produced to strict tolerances of the ISO 965-1 spec to maintain consistency and interchangeability between fasteners made by different manufacturers.
The ISO 7380-2 spec defines the dimensions for things like the head height, head diameter, hex key size and so on.
It’s important to understand the different materials used to produce these and the benefits each one offers. Consider the required level of corrosion resistance and the necessary strength of the screw.
It is highly unusual to find these in a metric fine pitch but if you do require a fine pitch version they could be specially manufactured for you.
Just like most other types of fasteners, to measure the length you would measure from under the flange to the end of the thread.
The IS0 7380-2 Spec
Here is a basic table with the most common sizes and dimensions of ISO 7380-2. Directly below this though, you can download a full-colour, full-spec version to keep for future reference.
| Size | Thread Diameter | Thread Pitch | Head Diameter | Head Height | Key Size |
| M2 | 2mm | 0.4mm | 4mm | 1.3mm | 1.3mm |
| M2.5 | 2.5mm | 0.45mm | 5.5mm | 1.5mm | 1.5mm |
| M3 | 3mm | 0.5mm | 7mm | 1.65mm | 2mm |
| M4 | 4mm | 0.7mm | 9.4mm | 2.2mm | 2.5mm |
| M5 | 5mm | 0.8mm | 11.6mm | 2.75mm | 3mm |
| M6 | 6mm | 1mm | 13.6mm | 3.3mm | 4mm |
| M8 | 8mm | 1.25mm | 17.8mm | 4.4mm | 5mm |
| M10 | 10mm | 1.5mm | 22mm | 5.5mm | 6mm |
| M12 | 12mm | 1.75mm | 25mm | 6mm | 8mm |
Enter your details below to be emailed a full-colour, full-spec PDF of the ISO 7380-2
Conclusion
Socket flange button head screws are a great option for the secure fastening of many parts in different situations. They take the visual appeal of a standard button head and incorporate a useful flange that offers many benefits over a standard type screw head.
You can enhance the load-spreading capabilities of their heads by using a penny washer if the diameter of the head is not enough.
These are great versatile fasteners that can be used in many areas whether for their looks, their unique enlarged head or their low profile snag resistant heads.
Think about the environment and the conditions they will be present in and make an appropriate decision on the material you will need to select.
As always, we are happy to answer any questions that you might have, just give us a shout. If you want more help or need an ISO 7380-2 dimensions chart PDF, contact the team today.
Frequently Asked Questions
Where Can I Find An ISO 7380-2 Dimensions Chart PDF?
To find a PDF chart with ISO 7380-2 dimensions, you simply need to scroll up this page a little. Not only is there a chart with basic dimensions for quick referencing, there is also the option to have an ISO 7380-2 PDF sent to you that you can keep for future reference.
What Are the Main Uses of Hex Flange Button Head Screws?
They are mostly used in applications requiring a wider-than-usual head diameter. This can be to cover an unsightly hole, to cover an elongated slotted hole or the spread the load on softer material where a standard screw might indent into the surface.
How Do Socket Flanged Button Screws Differ From Button Heads?
The main difference is in the flange. Socket flanged button screws have a flange that works like a washer, this helps with load distribution. Standard button head screws do not have this feature. This difference greatly impacts how well they perform and also opens up their usage to so many different other applications.
Can Socket Flanged Button Screws Be Used in Outdoor Applications?
Yes, socket flanged button made from stainless steel are great for outdoor use. There is the choice between A2 & A4 depending on the environment they will be subject to.
What are the advantages of using socket flange button screws in mechanical applications?
Socket flanged button screws are great for load distribution. They have a built-in flange that helps lower stress levels and stops damage to parts. This feature makes them especially useful in machines where vibration or stress could be a problem. The use of shake-proof washers can further enhance this if needed.
What are flanged screws?
Flanged screws are fasteners that have a flange or lip under the head. This flange works like an integrated washer. Its design helps spread the load better and creates a tighter seal. This makes flanged screws great for different uses, particularly with softer materials.
What Is An ISO 7380-2 Screw?
An ISO 7380-2 screw is a socket button head screw built to the ISO 7380-2 standard, which includes a flange. This standard sets the sizes and limits for these screws which helps keep consistency.