Your required torque specs are typically fastener related if you aim to achieve proper clamping force. Best example: Cylinder heads or con rods. You stretch the fasteners into their elastic state to get them to act like a pre-loaded spring.
In your example, for the bracket to upright (did I get your question right?) use any engineering book or fastener supplier's handbook to find the torque specs. Make sure you use the correct (or no) lubricant.
To learn more about this "mess" get ARP's catalog & tech articles. And Carroll Smith's book about nut, bolts and fasteners.
https://www.amazon.com/Nuts-Bolts-Fa.../dp/B001OXCTSI
https://arp-bolts.com/p/technical.php