Amazon: thread inserts
40 Pcs Threaded Inserts, M6 x 20 Threaded Inserts, Nut Threaded Wood Inserts with Hex Spanner, Carbon Steel Furniture Screw in Nut Threaded, Bolt Fastener Connector for Wood Furniture. 4.8 out of 5 stars 22. $8.99 $ 8. 99. Get it as soon as Tue, Sep 13. FREE Shipping on orders over $25 shipped by Amazon.