Question: Is there a standard for multiple-start ACME screws as there is for single-start ACMES?

Answer:  Not specifically.  ACME screw thread specification ASME B1.5-1997 applies to single-start screws but includes allowance and tolerance recommendations for multiple-start screws as well.  When using multiple-start ACME screws it is good practice to purchase the screws and nuts from a single source to ensure good fit-up and good performance.  All Rempco multiple-start screws guarantee users of long, trouble-free service life and future interchangeability.