Abstract: A casing centralizer having a pair of longitudinally spaced collars adapted to be assembled about a conduit, and a plurality of outwardly bowed springs extending longitudinally between the collars. Each collar has internal and external upsets formed therein. The external upsets are generally U shaped to receive the end of the bow spring. Each bow spring has an opening at each end thereof adapted to receive the internally upset material, with the internally upset material so formed to extending into the bow spring opening thereby locking the end portion of the bow spring within the externally formed U shaped upsets.

Abstract: A casing centralizer having a pair of longitudinally spaced collars adapted to be assembled about a conduit, and a plurality of outwardly bowed springs extending longitudinally between the collars. Each collar has internal and external upsets formed therein. The external upsets are generally U shaped to receive the end of the bow spring. Each bow spring has an opening at each end thereof adapted to receive the internally upset material, with the internally upset material so formed to extending into the bow spring opening thereby locking the end portion of the bow spring within the externally formed U shaped upsets.

Abstract: A centering device or centralizer for mounting on oil well tubings and similar conduit strings, the invention acts to maintain substantially uniform clearance between such strings and a wellbore. The centering device of the invention differs from prior non-welded centering devices in that the present device does not require bending or deformation of any of its structural elements during assembly or disassembly yet displays the necessary stand-off characteristics during utilization of the device within the wellbore to assure uniform clearance between the wellbore and the casing. A particular feature of the invention is an independent retaining ring which securely attaches a plurality of structural elements to form the present centering device.