Q: We are a manufacturer seeking a fastener for an air cooled engine’s head bolt replacement project. The fastener would be used to hold a aluminum cylinder head. We would like to use 17-4PH but are concerned about galling?
A: As you would be using two different materials, the 17-4PH and the aluminum, you will be less likely to see galling. To be safe, we suggest using sell a high temp anti-seize (Extreme Anti-Seize) which will minimize any galling. This molybdenum disulfide based paste can handle temperatures up to 2400°F and lower installation friction. As a result, this will lower the incidence of seize, heat-freeze and galling. These lubricants are also resistant to contraction, expansion, or vibration.