Historical clue formulations

• Ridged rod in construction — 2025-10-03
• Steel support for concrete — 2025-03-18
• Concrete support — 2024-01-14
• Steel support for concrete — 2022-08-08
• Support structure — 2020-03-07
• Steel support for concrete — 2017-04-11
• Masonry-supporting rod — 2015-12-26
• Slab strengthener — 2014-02-21
• Steel support for concrete — 2012-05-13
• Foundation strengthener — 2009-10-24
• Steel support for concrete — 2007-09-13