Hex bolts are a unique style of fixing used throughout the construction, automobile and engineering industries. The hexagon bolt fixing is a reliable fastener for a wide selection of building projects and repair jobs.
Hex Bolts come in various finishes and thread designs for application in different tasks and environments. Do you know which one is best for your project? Find out what you need to know about Hex Bolts below.
What are Hex Bolts?
Many screws and bolts are identified by their drive style. Unlike the ‘standard’ Phillips or Slotted drive, hex bolts are distinct because of their six-sided (hexagonal) heads.
This style of bolt is the industry standard for fasteners with forged heads. While most hex bolts are partially threaded, fully threaded hex sets are also widely used.
Why use hex bolts?
Hex Bolts are designed to be used throughout the construction and engineering industry, whether that’s on two distinctly different projects or as fixings on different materials on the same building. That’s because they are a versatile fixing suitable for lots of jobs and materials.
The hexagon head is convenient for gripping with tools from all angles and can also be grabbed by hand. It makes them easy to loosen and tighten because there’s space to use your tools from all directions.
Hex bolts are good fixings because they are manufactured specifically to meet environmental and tensile specifications.
When to use hex bolts?
Hex bolts can be used for infrastructure that requires a strong fastener with high tensile strength properties due to their design and base materials. As mentioned, they can also be used in tight spaces with limited access because tools can access them from all angles due to the six points of contact on the hex head.
With different finishes, lengths and thread styles, they can be used for fastening wood, steel and other construction materials so aren’t limited for application on site.
The main uses for hex bolts are in docks, bridges, highway structures and buildings. This style of bolt is popular in all assemblies and is a real staple of the industry across the world because of its diverse application, fastener design and choice of variations.
Choosing hex bolts
Whether it’s finish, thread or size, the specification of hex bolt will depend on your needs.
Stainless steel hex bolts aren’t just strong and resistant because of their finish. The entire body of the bolt is made from stainless steel. Stainless steel is corrosion resistant so can be used in high-saline locations where other fasteners would rust too quickly. They are also a common choice because they don’t need coating.
A2 and A4 fixings indicate the levels of chromium in the stainless are both extremely corrosion resistant. For any M&E and BES engineers working in a marine environment, the best s/s fixing would be A4. For industry ‘near’ a marine environment, A2 is usually suitable.
We’ve written an entire article to help you decide if stainless steel fixings are right for you.
BZP Hex Bolts are the most common finish with fixings. It stands for bright zinc plated. An advantage of BZP finish is that it’s aesthetically pleasing and makes sure all fixings are uniform.
However, the BZP layer is thin which makes the steel resistant to moisture but won’t prevent rusting or oxidising in an external or outdoor environment.
The Galv Hex Bolt finish with hot-dip galvanisation creates an element resistant finish. This fixing finish is cost-effective and low maintenance once installed. If you intend to cut galvanised hex bolts, remember that the zinc finish will disappear and leave unprotected metal.
Fully Threaded Hexagon Bolts, otherwise known as a ‘hex sets’, are designed for use in heavy-duty fastening applications. As the name states, these fasteners are threaded all the way up to the head of the bolt. This makes them great for installation into pre-threaded holes.
If your build is focused mainly on grip strength and less interested in alignment and shear strength, a fully threaded bolt is the best fastening solution. After application, a full thread bolt spreads pressure along its entire length, with the largest holding pressure placed on the head.
Plain hex bolts feature an unthreaded shank beneath the hex bolt head. This style of hex bolt is best for resistance and alignment. For a project that requires a lot of force to hold an object in place, a partially threaded bolt delivers the strength needed. The non-threaded segment, sometimes called grip length, has zero weak spots to prevent strain.
The entire fastening is more resistant to vibration and shear forces when the unthreaded portion is inserted into a correctly sized hole.
As with most bolts, hex bolts comes in M size times length size. For heavier applications, larger diameters are needed. Anchor Fixings stock hex bolts up to M48 and 270mm in respective sizes throughout products in our range.
Where to buy hex bolts
At Anchor Fixings, we have all the fasteners, fixings and accessories you need to complete construction and engineering projects quickly and to high standards.
We supply high-quality products that can be delivered straight to your site when needed!
Need more info for your fastening needs? Check out our previous blog posts:
This article was written by Anchor Fixings Director Andy Walker.