====== Bolts and Screws ======

===== Grades, hardness, tensile strength =====

https://www.engineeringtoolbox.com/steel-bolts-metric-grades-d_1428.html

https://amesweb.info/Screws/metric-bolt-grades-strength-calculator.aspx

https://www.albanycountyfasteners.com/Fastener-Reference-Tables-s/1157.htm

https://www.boltdepot.com/fastener-information/Materials-and-Grades/Bolt-Grade-Chart.aspx

https://www.schrauben-lexikon.de/

https://www.schrauben-katalog.net/din-normen/

https://www.fullerfasteners.com/tech/stainless-steel-data/

https://www.albanycountyfasteners.com/Fastener-Grades-Strength-and-Materials-s/1129.htm

https://www.graphskill.com/grades-of-stainless-steel-a2-a4-in-relation-to-fasteners/