The Probert Encyclopaedia of Science & Technology

STEMMING

In mining, stemming refers to a material employed to confine an explosive charge in a bore hole. The material used for stemming must be flexible, so that it can take the shape of the bore hole, and non-combustible, especially in coal mining. One of the best materials for stemming is damp fine clay which is rammed into position over the charge. Efficient stemming nearly doubles the explosive effect of the charge used.
Research Stemming