Shock Proof Dental X-ray Tube

Shock Proof Dental X-ray Tube

This appears to be a shock proof dental X-ray tube—almost certainly manufactured by General Electric. The only visible markings are stamped on the tube's brown cylindrical jacket: F95374. Part No. 3105-G-10.

The jacket consists of six or seven layers of thin lead sheets separated by what might be laminated paper impregnated with phenolic resin. A hole in the jacket permits the X-rays to exit the tube.

Shock Proof Dental X-ray Tube close up

Size: Approximately 4" long, 2" diameter

I identified the lead by X-ray fluorescence analysis. My guess about the material separating the lead sheets is based on a paper by M. J. Gross, the original owner of the tube, in which he describes the laminated paper as being the best material for a solid insulating jacket around X-ray tubes. The lead would provide shielding of the X-rays while the paper's high dielectric strength would protect the dentist handling the tube from electrical shock.

Gross worked with Dr. Coolidge at General Electric in Schenectady N.Y., and later became Vice President of the GE X-ray Company. During the 1930s and 1940s, Gross and Zed Attlee formed the core of Coolidge's research and design team.

Kindly donated by Malvern Gross Jr. in memory of his father.


Gross, M. J. Progress in the Design of Shock Proof Roentgen Tubes for Therapy and Industrial Roentgenography. Am. J. Roent. Radium Therapy. XXXIV, No. 4, pp 518-522. October, 1935.