Q: What is the difference between a screw made to ASTM A1014 and AMS 5663?
A: ASTM A1014 is standard specification for precipitation hardened bolts in Inconel 718 (UNS N07718) for high hemperature service by ASTM International. In contrast AMS 5663 is the material standard from another standards agency: SAE International.
ASTM A1014 specifically focuses on material standards for bolts, whereas AME 5663 is a broader specification for the material.
Both standard describe similar heat treatment (solution annealing and hardening), so a fastener according to to ASTM A1014 and AMS 5663 will have similar characteristics (a tensile strength of 185 ksi (1275 MPa) and a Yield strength of 150 ksi (1035 MPa).
Stress rupture test ASTM 1014 describes Tensile requirements at elevated temperature of with at tensile strength of 145 ksi (1000 Mpa) at 1200 F (650 C) and Yield strength at 125 ksi (860 Mpa) at 1200 F (650 C).
SAE does also have a standard specifically for Bolt and Screws AS7466 where the material is tested at 800F to have tensile strength of min 155 ksi at 800F and a yield strength of min 130 ksi at 800F