A sherardized product with a thin coating is deformable. This is partly due to the crystalline surface of the zinc alloy.
Spring steel retains its most important property, without cracks forming in the sherardized (diffused galvanized) layer.
Another example is rivets. After riveting, both ends have the same head. The zinc layer still protects the riveted nail against corrosion and can undergo any further processing in this form.