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The latest generation of concrete screws allow for direct fixing into masonry by pre-drilling a hole and allowing the fixing to cut its own thread – much stronger and much quicker!
Paul Kershaw Owner, manager & buyer
With over 30 years of experience in the building supplies industry
Today we’re sharing a general overview of masonry bolts and concrete screws. We’ll start with masonry bolts, which are great for heavy-duty applications. Keep reading to learn more about concrete screws, which are a light-duty solution most commonly used to fix windows and door frames.
Before the invention of modern concrete screws and bolts, builders had to rely on labour-intensive, time-consuming methods for attaching materials to concrete. One of the most common methods was the use of shield anchors. These consisted of a metal shield that would expand against the sides of a drilled hole when a bolt was tightened, creating a secure grip.
The shield anchor, while popular, had its disadvantages. For one, there was the risk of cracking the concrete if the anchor was over-tightened. These types of masonry bolts were also unable to be used in weaker materials or thin concrete slabs due to their expansion mechanism. Resin anchors, chemical fixings, and studs were also used. However, all these methods required precise drilling, alignment, and additional waiting time for materials to set or expand.
These traditional alternatives to modern concrete screws often needed very precise work. And, if things went wrong, they could weaken the attachments or require the job to be reperformed. For instance, the force needed for hammer-driven methods and expanding anchors could damage the concrete. Some methods were also unable to hold much weight, making them unsuitable for heavy-duty jobs.
Modern concrete bolts have a number of advantages over their more traditional counterparts. Namely, they are a lot easier and quicker to attach to concrete and other hard materials, and can handle a great deal more weight.
Unlike the shield anchor, modern concrete and masonry bolts provide a grip all along the shank of the bolt. This makes it much more secure. You can just drill a hole and screw the bolt in without needing extra parts, like anchors or resins. This method is great for many different jobs. Plus, it’s easy to use and doesn’t require a lot of strength, so it’s less likely to cause injuries or wear you out.
Masonry screws work well in lots of different materials: not just concrete but also brick and aircrete material. This makes them very versatile and suitable for all sorts of projects. Overall, these modern screws and bolts are a big improvement from the old ways of attaching things to concrete. Jobs are now faster, stronger, and easier to do.
Fixing modern concrete and masonry bolts really couldn’t be simpler. Take a look at the product information for each bolt on our website to see the drill hole size required. In most cases, the drill hole size will be the same as the gauge of the bolt. For example, if the masonry bolt size is 10 x 100mm, then the required drill hole size will be 10mm. Therefore, you will need to use either an SDS Drill Bit, a traditional Masonry Drill Bit, or a multi material drill bit that is 10mm thick and has a working length over 100mm.
To drive the bolt into the concrete, you can use a ratchet to manually wind the bolt in, or use an impact socket drive.
I was a sales rep at Unifix in the early 90’s, who launched the Thunderbolt brand of the masonry bolt. They were one of the first two brands to develop this type of product. Even though it was launched in the early 90’s, there are still lots of builders who do not use or even know this product and instead use the traditional, inferior shield anchor bolts. These “new” bolts are not just stronger, they are much easier to fix because they are fixed in situ. With the shield anchors, the process to fix involves more stages and is a bit fiddly. The masonry bolts are much simpler and save a lot of time. I always recommend these bolts when people enquire about fixing into masonry.
Paul Kershaw Owner, manager & buyer
With over 30 years of experience in the building supplies industry
So, what’s the difference between concrete screws and masonry bolts? Put simply, concrete screws are the screw version of masonry bolts. You just need to drill a pilot hole and then screw the fixing in.
It is usually advised that a 6mm drill bit is used for stone, brick, or concrete blocks. That said, if you’re fixing into concrete, a 6.5mm drill bit will be needed. You can use either SDS Drill Bits, for use in an SDS Drill, or standard Masonry Drill Bits. The concrete screw range available at Tradefix Direct is ideal for fixing windows and door frames into concrete or masonry.
Are you looking for concrete bolts or screws for your next project? Browse our full range online! If you’re unsure which product you need, don’t hesitate to get in touch and we’ll be happy to talk you through the best options. You can also find more helpful guides and resources in our other blogs!
