Set screw shaft collars are used on shafts in power transmission applications such as thrust collars, arbor spacers, sprocket hubs, bearing holders and shaft protectors. The hardened set screw in the shaft collar is used to hold the collar in place when it is tightened, gripping the shaft. The collar is made from zinc plated low carbon steel providing moderate corrosion resistance and the set screw is made from medium carbon black oxide coated hardened steel for moderate corrosion resistance and strength.