Pin (in wireline tools) 2 : A small piece of steel, brass, aluminum bar stock that is designed to break on a certain impact or pressure load and enable another tool function
George E. King Engineering, 5000 Oilfield Terms: A Glossary of Petroleum Engineering Terms, Abbreviations and Acronyms, US 2010. http://gekengineering.com/Downloads/Free_Downloads /Glossary_of_Petroleum_Engineering_Terms_25_August _2010.pdf, (Oil - Amer) {593}