@roalco - Good catch - yes, you’re right for the basic & I had to go look in my Excel file as to why I had shy of 20 safe working and a good margin to break -30K was my mental “break spec”.
I bought mine via Masterpull in Bellingham (they storefront for Samson/Amsteel as they are based in Ferndale).
I have 125’ of the mid-grade, here:
Master Pull manufactures high performance vehicle recovery equipment and rigging for a wide range of applications, from recreational off-road to heavy duty military and industrial use.
www.masterpull.com
-So you were right for the entry Amsteel rope, I’d gotten my mid-level as a over-run discount on the black color, otherwise I bet I’d have the ~7/16” or 1/2” standard line.
I’m glad I kept my Excel doc updated, otherwise I’d be wondering where I had gotten the spec I’d been mentally running on.
I splurged on the 18K Warn Epic snatch & the big-boy Bubba soft shackles, so I’d known I bought stout line for a M12K winch.
Either way, anybody should look at the specs themselves & decide on what grade to buy.
Hindsight - a M12k spool would hold 125’ of either 7/16 or 1/2 rope. So you could get ~30K rated rope for probably less $$ than my 3/8 mid-grade would MSRP for.