The rod is textolite f 40 x 500 mm

The rod is textolite PTK
Electrotechnical round textolite rods of various diameters are designed for long-term operation in a transformer oil environment as an electrical insulating material. The operating temperature range is from -60°C to +120°C with a relative humidity of 45-75%. The use of core textolite (in addition to transformer installations) - blanks for the manufacture of parts of mechanisms and machines: bushings, fingers, sliding bearings, gears, gaskets, etc