Flange bolts

What are flange bolts?

To distribute the load over a larger area, flange bolts (also known as washer bolts) feature a flange cast into the bolt head. This kind of bolt, which is frequently used in the auto industry, for instance, permits significantly quicker installation on an assembly line than a typical bolt and washer.

A flange bolt distinguishes from a standard bolt in that it has a greater surface area underneath the head to ensure that clamping pressure is distributed evenly. This larger surface functions as a washer, therefore this type of bolt doesn’t require the addition of one.

Flange Bolt specifications and dimensions

Metric and serrated flange bolt suppliers in UAE

What is a flange head bolt?

Flange bolts do have a round flange beneath the head that distributes the load like a washer. Non-serrated flange bolts are frequently referred to as frame bolts.
To distribute the load over a larger area, flange bolts (also known as washer bolts) feature a flanged cast into the bolt head. This kind of bolt, which is frequently used in the auto industry, for instance, permits significantly quicker installation on an assembly line than a typical bolt and washer.

Hex head and automotive flange bolts for a automobile and chemical industries

Where can you use a hex flange bolt ?

On vehicle frames, particularly truck frames, and anywhere else a hex washer head bolt is required, hex flange bolts are employed. They can be used with enormous and irregularly shaped holes due to the large bearing surface’s ability to evenly distribute clamping force. Grade G Flange Style Lock Nuts are frequently used to provide a bolt/nut combination that resists slipping and spans a significant area. Hex frame flange bolts, hex washer frame bolts, and hex flange screws are other names for them.

Flange bolt types

Flange head bolt and hexagon flange bolt are available at 1/4 to 24 inches

What size is a hex head flange bolt ?

The size of the head is determined by the size of the flange bolt; the flange diameter of hex types is more than 2.1 times the bolt size, whereas the flange diameter of 12-point heads is significantly less at approximately 1.5 times the bolt size. Tables 1 and 2 include information on head width across flats, sometimes known as the wrench size, as well as head height, frame bolts diameter, and head width across corners.

Check dimensions, standard, torque chart and specifications of black flange bolts

How do you torque a serrated flange bolt?

To get a good seal with a flanged connection, you need to be sure that all of the components are correct. Incorrect installation practices are by far the most common cause of gasketed joint failures that result in leaks.

During the initial pass, you should only lightly tighten the first bolt before moving directly across or 180 degrees for the second bolt, then moving a quarter turn around the circle or 90 degrees for the third bolt, and finally moving directly across for the fourth bolt. Proceed with this process until all of the bolts have been secured. When you are tightening a flange that has four bolts, you should employ a criss-cross pattern.

View advantages and disadvantages of pipe and button head flange bolt as per DIN 6921, EN 1665 and ISO 4162 standard

Advantages and disadvantages of metric flange bolts

Advantages:

• On the global markets, they are interchangeable. Due to the accessibility of tools, parts can be put together anywhere in the world.
• Local vendors offer replacement fasteners for sale.
• A flange, which typically consists of two flange pieces and numerous fastening bolts, connects two large-diameter pipes.
• Flanges constructed of carbon are known as carbon steel flanges.
• Low-carbon steel is highly malleable and has low strength.

Disadvantages:

• High material cost when compared to rivets.
• The tensile strength of the bolt diminishes and stress concentration takes place as a result of the reduction in the bolt’s area in the threaded portion.
• Bolted connections become looser in the presence of dynamic loads and shock loads.