The railroad pick combines a spiked pick blade and a adze blade that has a narrow cutting edge. It is basically a lighter version of the pick mattock in that the spike and adze are both smaller. The spiked blade is for better penetrating solid materials and the adze is used to cutting and digging.
A pick mattock combines the function of a pick and adze, with a pointed end opposite an adze blade. This head type is perfect for all-around use. The pointed end is ideal for breaking up the soil, excellent for digging into more complex surfaces. After digging with the pointed end, the adze end is very suitable for cleaning the sand and rock inside.
A cutter mattock features a vertical axe blade on one side of the head and a horizontal adze blade on the other. The vertical axe blade can be used for cutting through roots in the ground, while the adze is used to dig or hoe the earth. The ability to use the weight of the head to strike the soil can make it more effective at digging soil than needing to apply force with your foot on a spade.
Not only need to clean your pick mattock from time to time, but also pay attention to whether your pick mattock is sharp after prolonged use. Both ends of a mattock should be maintained to keep a reasonably sharp edge; this can be done with either a grinder or a hand file.
The adze blade and axe of a mattock should be kept clear of burrs and any severe dents/chips ground or filed out. The adze however should not be kept as sharp as the axe cutting edge, just simple cleaning and maintenance.