Gibraltar Industries said Wednesday that it has acquired the storage and postal products business of Steel City Corp., in its second recent purchase to add to its package of mailbox-related items.

Gibraltar Industries has acquired a Kansas company that makes mailboxes for apartment buildings and other multiple-unit uses, the Hamburg-based building products manufacturer said Tuesday.

Gibraltar builds home construction parts, everything from mailboxes to gutter covers to roof vents. Relatedly, Gibraltar makes mounting systems for solar panels on roofs. And in agricultural ...