A prop's rated load capacity drops as its extension length increases — a prop fully retracted can carry significantly more than the same prop extended near its maximum height, so always check the load-at-height table, not just the headline capacity figure.
Extension range should be matched to the floor-to-floor height on the project with enough overlap to handle minor site variations, without stretching props to their absolute limit, which erodes the safety margin the rated capacity assumes.
Pin condition and thread wear are the most common reasons a prop underperforms its rating over time — inspect rented props for bent pins or worn adjustment threads before use, since these defects are not always visible without a hands-on check.