40 Pack Threaded Insert Nutsert, 1/4"-20 x 15mm Screw in Nut Threaded Wood Inserts, for Wood Furniture(with 1/4" Allen Wrench): Amazon.com: Industrial & Scientific
POWERTEC QTI1002 1/4"-20 Threaded Insert for Wood | Zinc Plated Screw-In Nut for Woodworking – 50 Pack | a Woodworking Shop Essential | Superior Fastening | For Hard and Soft Wood and More - Walmart.com