Channel Nuts
Of course, no channel support system can be constructed without the nuts and bolts that hold it all together. Plain channel nuts are the commonest and cheapest option, available with threads from M6 – M16 - either pre-galvanised or hot dip galvanised; the latter offering the best protection against corrosion. Read more
For ease and speed of installation, you may want to investigate sprung channel nuts. These have a spring to keep the nut in place while you engage the bolt. Short springs for 21mm channel, and long springs for 41mm. These are especially useful if you are working in an awkward position. For even greater ease of installation, there are channel nut assemblies. For use with channel nuts, there is a range of suitable threaded fasteners here.