These tubes are made from special tubing to give the optimum wall thickness. They are well annealed, resistant to heat and chemically stable. Rims are fire-polished. The 25mm tube does not have a marking spot.
Approx. O.D. x Length mm:
Physics Atomic & Nuclear Electron Tubes Student Tubes - C-9800-20 - Beaded Rim Test Tube 20x150 576/ca
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