Churn drills are most effective in soft- to medium-density rock of relative shallow depth (10–50 metres).
Churn drills were invented as early as 221 BC in Qin dynasty China,[1] capable of reaching a depth of 1500 m.[2] Churn drills in ancient China were built of wood and labor-intensive, but were able to go through solid rock.
[2][4] A churn drill using steam power, based on "the ancient Chinese method of lifting and dropping a rod tipped with a bit," was first built in 1835 by Isaac Singer in the United States, according to The History of Grinding.
[5] In America, they were common in the Tri-State district areas during the lead and zinc mining in Missouri, Oklahoma, and Kansas.
There is an example of one of these machines at the Northern Life Museum in Fort Smith, Northwest Territories, Canada.