this is a half of a concrete baluster mold. In the early 20th century, these heavy iron molds were used to cast decorative concrete balusters—the vertical, vase-shaped posts used in railings for porches, staircases, and balconies. The piece you have is designed to form one end or a section of the baluster's profile, and it likely worked in tandem with another identical or complementary piece to hold the wet concrete until it set.

Approx 18 3/8" Tall by 10 1/2" widest (10" across top and 10 1/2" Bottom) by 5"

Weighs approx 19 lbs unboxed.

Rust covered and some pitting and pin holes 

As pictured

History

• The Manufacturer: The Simpson Cement Mold Company was a prominent American manufacturer based in Columbus, Ohio (often abbreviated as "Col. O" on their products). They were very active in the early 1900s, selling equipment to contractors and homeowners for "on-site" production of ornamental concrete products.

• Era: This mold dates to the early 20th century (likely 1905–1920s), a period when cast stone and molded concrete became incredibly popular for residential and commercial architecture as a cheaper, durable alternative to carved stone.

• Significance: These molds represent a specific era of "do-it-yourself" masonry and the industrialization of architectural ornamentation.