We have been working with Atlas for many years using their Atlas CF flanges and explosion bonding capability for assemblies such as beryllium windows. When we had a need for a dipole magnet vacuum chamber, Atlas competed with vacuum equipment manufacturers worldwide and won the bid, beating out stainless steel vendors in Europe and Russia by a large margin. This is a large chamber ~2.9 m long with two 50 mrad acceptance aperture IR beamlines tangential to the synchrotron electron beam orbit. All flanges including e-beam orbit, synchrotron radiation ports and pumping ports were fabricated from Atlas CF flanges. In addition to the demanding geometrical constraints of the dipole magnet the chamber was required to absorb all excess synchrotron radiation not entering the beamlines and resist any deformation due to forces incurred under vacuum. Atlas presented a preliminary design for approval before fabrication and conducted a complete FEA analysis of the chamber studying both the thermal loading and the vacuum deflection. Atlas fabricated the chamber in two halves with each half having a water cooling surface machined into the chamber. The two halves were welded together and final machining brought the chamber overall thickness tolerance and chamber radius of curvature tolerance to less than 1mm. The chamber is presently installed in the CAMD synchrotron in bending magnet 2 and attains a base pressure less than 5 x10-10 Torr without bakeout.