In order to make a structure out of aluminium extrusions you need a way to fasten them. The first step that is covered in this post covers the use of aluminium profiles or extrusions, here we will cover aluminium profile fasteners.
Types of aluminium profile fasteners
There are many types of fastening aluminium extrusions, here we will focus on right angle fastening. I have used these profiles extensively and I have never had a need to connect profiles at an angle. So the right angle connection is enough to cover most of your needs. Here we are talking about connection two aluminium profiles. For connecting other stuff to aluminium profiles the most useful connection is a T-nut or a T-bolt. T-nuts were mentioned in the previous post.
There are a lot of different types of fasteners for aluminium profiles. Some manufacturers even have their proprietary type(s). I will cover the ones that I have used so far and these are also most common ones. If you come by some other types I believe that they will be similar to some mentioned here.
First the obvious ones.
Aluminium profile fasteners – 90 degree flat plate
Probably the easiest way to connect two profiles together. It’s pretty simple. All that you need are T-nuts some screws, DIN 7380 or others, and a plate with holes. You can make the flat plate by yourself pretty easily. For angled connections flat plates can also be used.
Aluminium profile fasteners – Gussets
Gussets are a simple strong method of connecting aluminium plates. For a gusset connection you will need T-nuts with screws for each screw hole on the gusset. Using gussets in the aluminium extrusion frame is similar to using gussets in a welded frame. Advantage over using the flat plate is that using gussets gives you clean sides of the frame. These connections are for right angle connection only.
Image Credit: http://www13.boschrexroth-us.com/Framing_Shop/Product/Default.aspx?category=10201
The names of the next couple of fasteners are borrowed from the resource’s dictionary. There might be different names from different manufacturers.
Aluminium profile fasteners – Automatic set
Automatic fasteners are advertised as “The fastest and most flexible profile connection”. The truth is that they are not very useful in my opinion. In the rest of this article you can see how to use them. For a secure connection you will need two of these fasteners. That just adds time in the assembly process. Also I personally do not see any benefit on using them over the other types.
Aluminium profile fasteners – Universal set
Universal set is one of the most commonly used. I believe that they are the highest strength connections. They are flexible connections because position of the profile beams can be adjusted even after the connection is set. Not all connections are like this. Standard set that we will talk abut later are clearly a rigid type. This fastener has always been the default one that I have used.
Aluminium profile fasteners – Standard fastening set
Standard fastening set is also a common one. A bolt and a proprietary washer make up this simple connection. This washer its into the groove of one of the extrusions. The other extrusion has thread cut into its center. The bolt secures the two profiles like in the picture bellow. This connection is rigid as that in order to tighten the bolt you need to provide a hole for a screwdriver or a hex key. These connections are commonly used as they are cheep and commonly available.
Aluminium profile fasteners – how to install
Automatic fastener -how to install
Process of installing automatic fastening set is presented in this video. Here the threaded part of the fastener is driven into the profile in order to cut the thread. This method is OK to use if you do not have a lot of connections. It does get tiresome after 10 or more connections.
Universal fastener -how to install
Here a video demonstrates how to use universal fasteners. In this video the holes are drilled “by hand”. It is not that easy to just drill a hole by a hand drill. First the position of the hole needs to be in +-0.5 mm so you do need to measure before you start drilling also the hole needs to be pretty large ~20mm so you need to hold the aluminium profile in a vise in order not to move. The easiest way if you have a lot of profiles to connect is just to mill the hole for the fasteners.
Standard fastener -how to install
In this connection you can see that a thread needs to be tapped in one profile and then the fastener is inserted. The second profile needs to have a hole drilled in order to tighten the bolt in the fastener. The video shows these holes drilled in the assembly process. When the right placement is selected you drill a hole for a hex key. The more realistic approach is to design the placement of the hole and to pre-drill it. This connection is rigid in the sense that is you want to move the connection slightly you would need to drill another hole for the hex key.
I hope that this post was informative. Now you have some basic knowledge on how to connect aluminium profiles.