Writing of this book was motivated by the lack of readily available design data for use in the design of pressure vessels, boilers, reactors, autoclaves, with varied cross-bore entry geometries and thickness ratios. The cross-bores include tee-offs or openings on the sides or end covers. The results presented form a quick design aid when engineers need to consider: elastic stresses; stress concentration factors; autofrettage; residual stresses; service stresses. This data will be very handy and save time that would be required to develop and run a computer program for analyzing the problem. The data is presented for both elastic and elastic-plastic stress loadings and for the following cross-bore entry geometries: plain; radiused; chamfered. Data for any cylinder thickness ratio is also integrated in the results. Because the stresses are presented in dimensionless form, the results can be applied in any linear elastic isotropic solid material of construction. The information will find use in: universities and technical institutes as a teaching or reference material; design offices; fabrication shops, International Standard bodies for integrating in the existing standards.