I have recently acquired seven solid graphite cylinders. Five of them are 5” in diameter x 14” long. The other two are 7” in diameter x 14” long.

I would like to have some of this material machined onto rocket motor nozzles and knowing the grade would be helpful.

They all have the number 3499S and a 0 stamped on the end.

I have searched online but could find nothing that matched those numbers. I have found data containing graphite grade numbers and their corresponding densities.

If I determine the density of the material and match it up with something online can I assume that it is that grade material or are there other factors I need to consider?

It is not sintered and does not appear to be impregnated with any type of metal.