Never-Seize and Lubricants

A bit on "Never-seizing threaded members for high temp use; I was privileged o run the R&D test lab for VOGT for 17 years. Since VOGT made valves for high temp service such as class 2500# steam a high temp never-seize was needed to allow the dis-assembly of bolts and the like after long exposure to temps in the 1200F range. So test articles of the cr-moly steel valve bonnets were made, coated with the never-seizes we had bought , and then torqued to high torques. These threaded joints were about 2.5" diameter with 12 threads per inch. Torqued to about 800 pound/feet. Then off to my 1000f test furnace to back for a couple of weeks. We tested every brand and type of never-seize on the market. There were ONLY 2 that allowed the dis-assembly after this test. One was a tungsten di-sulfide aerosol spray at about $200 a can, and Dow Corning anti-seize 1000. The Dow corning product has an approximate cost today of about $15 a pint can.

While on this subject, we also installed maybe a million 316LSS bolts a year into 316L bodies a year. Again tested every lubricant and anti-seize on the market. Since this was a room temp install, the Dow Corning GN assembly paste was the winner by a country mile and it is available in a lifetime supply of a pint for maybe $25. Life time supply for a blacksmith as a tiny amount of this roughly 70% moly DI-sulfide paste will cover you from head to toe if you keep rubbing. The one thing to be very careful is that this GN paste reduces friction by about 40% over plain grease and therefore it achieves clamp load in the bolt through bolt stretching at about 40% less torque.

Moly DI-sulfide is a natural mined mineral. It has the unique property of having a compression strength of about 350,000psi, yet has a shear strength of near zero. So keeps the loaded metal from ever touching, but shears and acts like slip plates to allow the metal to slide. Since the moly powder is incredibly fine it gets into the cracks and fissure of you hands when you get it on you, and pretty much has to wear out.
Moly grease that has over about 2.5% moly will not pump through grease guns nor should it be used in roiller or ball bearings. 2.5% moly is placed in ball joints on cars at the factory and they last usually for the life of the car. Before moly grease ball joints were a regular lube item and usually had to have fresh grease every 3-5000 miles.

Written by Jeff Reinhardt