Choose a greasable design in these conditions.
High radial load with shock character. Hardened steel on steel contact surfaces carry higher dynamic load ratings than PTFE lined versions. Do not use steel on bronze for shock loads because bronze is too soft and will deform. A greasable steel on steel rod end handles impact loading best. This includes applications like agricultural equipment and heavy construction linkages. It maintains its capacity over a long service life when you grease it properly.
Contaminated environments where contamination can be purged. In agricultural, construction, and mining applications, mud, grit, and water penetrate bearing seals. A greasable design allows you to purge contamination by pumping fresh grease until the old discolored grease exits the seal. A sealed PTFE-lined bearing traps whatever enters the liner contact zone, and you cannot flush it out.
Long asset life is the goal. In applications where the machine is expected to run for 10 to 20 years with rebuilds rather than full replacement, greasable rod ends kept on a disciplined maintenance schedule outlast sealed designs. The sealed design has a fixed liner life that cannot be extended. The greasable design’s service life is directly tied to maintenance discipline.
Where greasable designs fail in practice: the maintenance never happens. A greasable rod end that misses three service intervals in a row runs dry and fails faster than a self-lubricating design would have. If the machine is in a location where maintenance access is genuinely difficult, or if the maintenance culture in your operation cannot reliably execute a greasing schedule, a self-lubricating design is the more honest engineering choice. A maintenance-free design that works is better than a theoretically superior greasable design that gets ignored.