Exhibit 24

SPECIAL POWER OF ATTORNEY
The undersigned is an officer and/or director of
Reliance Steel & Aluminum Co., a California corporation
("Reliance"), and hereby constitutes and appoints Karla Lewis,
Executive Vice President and Chief Financial Officer of Reliance,
and Kay Rustand, Vice President and General Counsel of Reliance,
or either of them, to act severally as attorney-in-fact and agent,
with power of substitution and resubstitution for each of them
in any and all capacities to prepare and sign any Form 3, 4 or 5
or any similar report, or any amendment thereof, to report the
undersigned's beneficial ownership of Reliance securities
or any changes in such beneficial ownership of Reliance securities
and to file any such report or amendment with the Securities and
Exchange Commission and the New York Stock Exchange or
any other appropriate regulatory agency, and the
undersigned hereby ratifies and confirms all that said
attorneys-in-fact, or substitute or substitutes, may do or cause to
be done by virtue of this Special Power of Attorney.

IN WITNESS WHEREOF, the undersigned has
executed this Special Power of Attorney in Doylestown,
Pennsylvania to be effective as of April 1, 2010.

/s/ Stephen Paul Koch
Name: Stephen Paul Koch