The NLGI consistency number is also a component of the code specified in standard ISO 6743-9 “lubricants, industrial oils and related products (class L) — classification — part 9: family X (greases)”.
Besides consistency, other properties (such as structural and mechanical stability, apparent viscosity, resistance to oxidation, etc.)
The cone is placed so that its tip just touches the grease surface and the dial indicator is set to zero at this position.
The following table[2] shows the NLGI classification and compares each grade with household products of similar consistency.
Greases with a higher number are firmer, tend to stay in place and are a good choice when leakage is a concern.