Low-carbon steels (AISI 1005-1026, 1108-1119, 1211-1215, and 1513-1527 ), by definition, contains less carbon than other steels and are inherently easier to cold-form due to their soft and ductile nature.
When strength is not a major concern, low-carbon steels are good choices because they are easy to handle (draw, bend, punch, swage, etc.) and fairly inexpensive. Surface hardness can be improved by a process called carburizing which involves heating the alloys in a carbon-rich atmosphere. Low-carbon steels that are usually carburized are AISI 1015, 1018, 1020, and 1117.