Stainless Steel cable
Diameter Break Strength

1/16" 270 lbs
3/32" 480 lbs
1/8" 920 lbs
3/16" 1700 lbs
1/4" 3700 lbs

ALWAYS use 5x design factor.
ALWAYS use redundant hanging points.
ALWAYS specify hardware rated by the manufacturer for flying speakers.
Copper, oval sleeve clamps are stronger than the cable; The cable will break before the sleeve slips.