INTRODUCTION In 1954 a group of users and manufacturers of sucker rod pumping equipment undertook a study in depth of the many complex problems associated with this means of lifting fluid from a well. To control and direct the effort, Sucker Rod Pumping Research, Incorporated, a non-profit organization was created. The services of Midwest Research Institute at Kansas City were retained to perform the work necessary to achieve the objectives of the organization. As a part of this project, more than 1100 polished rod dynamometer cards were taken with the electronic analog simulator at Midwest Research Institute. These were reorganized and presented in catalog form as Summary Report Vol. II of II, January 1 - December 31, 1960, M.R.I. Project No. 2376-E.Sucker Rod Pumping Research, Incorporated, before its dissolution, released this catalog of cards to the American Petroleum Institute. It was determined by the Committee on Standardization of Production Equipment at the Midyear Standardization Conference and reported in Circ PS-1382 dated August, 1969 that the catalog would be published by the API Dallas office for the cost of reproduction. Nomenclature is that used in API RP 11L: Recommended Practice for Design Calculations for Sucker Rod Pumping Systems. The cards were derived for many combinations of the independent non-dimensional parameters Fo/Skr and N/N6. The cards are published for information and reference. A discussion of the information presented, including an explanation of the numbers and material on the card sheets, may be found in the following paragraphs. Suggestions for card use are also given. This discussion is included through the courtesy of Mr. M. H. Halderson, Phillips Petroleum Company.