$10-9$ Listed in the tables are six springs described in customary units and five springs to described in SI units. Investigate these squared$-$and$-$ground$-$ended helical compression $10-19$ springs to see if they are solid$-$safe. If not, what is the largest free length to which they can be wound using $\backslash ($ n$\_\{$s$\}=1\mathrm{.}2\backslash )?$