The authors agree that the surname derives from the medieval name or nickname Maccaferro, linked to the expression ammaccare il ferro ("to dent the iron"), and that its main presence is concentrated in the region of Emilia-Romagna, especially in the Bologna area.

E. De Felice and F. De Laurentiis agree that the nickname Maccaferro was formed from the Emilian dialect (a)machèr ("to dent") and fèr ("iron"), with the sense of "he who dents the iron", and that it would have been given in allusion to the physical strength of the bearer.

E. Rossoni broadens this reading and places the origin of Maccaferro in the warrior and chivalric culture of the Middle Ages, where it functioned as an auspicious name for a future skilled fighter, possibly through the mediation of the French mâchefer. In that context, "to dent the iron" alludes to striking or piercing the adversary's armour. Rossoni also notes that the surname may come from the fixing as a surname of a personal name, although in some cases it could derive from war nicknames or from occupational names. He adds that the form Maccaferro, much rarer, is recorded in the Viareggio area —province of Lucca, in Tuscany— and in the Piceno area, between San Benedetto del Tronto and Grottammare, in the region of the Marche.