Have tough involved question. Have made cpl conventional rods from 9' 12wt fly blanks. These are fast action with 6.5 tip. Have found some inexpensive steelhead blanks that are 9' fast action6 tip im6 graphite of course it has a line 10-20 believe hvy action. I know that there are so many variables but how close does anyone think the steelhead blank would come close to 12wt fly blank-they came out great. Thanks for any input-Bill

Bill,
Without more info on the blanks, I'd guess the medium heavy steelhead blanks you mentioned would be similar to the 12 wt blank.

Take a look at the CCS Data site and see if they are there to compare the numbers ?

My favorite steelhead spinning blank is made from 9'-6" 2pc 8wt of better than entry level graphite. I would only trust this to break 10# safely without blank failure. I add a fighting butt of about 4-5" making the overall length of 9'-10" then I can achieve what I call a ferrule sync spacing of the guides, that allows both pre-rigged, mated (side by side), and ready for transport blank sections to sit (lined through the aligned guides on either side of the ferrule) such that the fragile tip section is protected by the longer butt section on either end. I can do this with 11 guides 3 on the butt section. 10# leader is about all you ever need for Steelies. I like a fly rod blank because it has a parabolic action over the 80/20, 70/30 type of dual action type of traditional spin rod blanks. The 8wt. is nice and around here (Michigan) and sought out as a high water steelie rod, 7wt. for low water. Those 12 wts we think of as a Fl . 70# Tarpon rod. An 8 wt is also a good Coho Salmon rod as they don't run near as big on average as King Salmon. I like the old 05' SCIII Avid 8 wt. with a lifetime warranty. I also have built nice steelie blanks out of 10' 8 wt. Pac Bay traditional fly rod blanks, lengthened to 10'-4" (4 guides on but section) but Pac bay does not honor its guarentee if you build a spining rod out of a fly blank