What is the difference between an external thread and internal thread with respect to bolts and nuts? How would you know which one requires which bolt/ nut pairings? - Quora
For a bolt and nut, do the nut have a right and wrong side (like the top and bottom)? It seems to me one side is flatter than the other. - Quora
![9 Sizes, 350PCS Drywall Anchors and Screws Assortment Kit, Includes Plastic Wall Anchors and Zinc Plated Steel Self-Drilling Anchors with Organization Box (Assorted Wall Anchors 350pcs): Amazon.com: Industrial & Scientific 9 Sizes, 350PCS Drywall Anchors and Screws Assortment Kit, Includes Plastic Wall Anchors and Zinc Plated Steel Self-Drilling Anchors with Organization Box (Assorted Wall Anchors 350pcs): Amazon.com: Industrial & Scientific](https://m.media-amazon.com/images/I/71T0UwuScEL.jpg)
9 Sizes, 350PCS Drywall Anchors and Screws Assortment Kit, Includes Plastic Wall Anchors and Zinc Plated Steel Self-Drilling Anchors with Organization Box (Assorted Wall Anchors 350pcs): Amazon.com: Industrial & Scientific
![Vintage Lot of Mixed Nuts and Bolts, Nuts and Bolts, Hex Socket Cap Screws, Hex Nuts, Flex Cap Screw Bolts,nuts Bolts,old Tools,old Hardware - Etsy Vintage Lot of Mixed Nuts and Bolts, Nuts and Bolts, Hex Socket Cap Screws, Hex Nuts, Flex Cap Screw Bolts,nuts Bolts,old Tools,old Hardware - Etsy](https://i.etsystatic.com/20802028/r/il/1710e8/5304138490/il_570xN.5304138490_pmgx.jpg)