Depends Christos !
In the case of Daiwa's & Shimano's quality blanks ??
Well I dont know for certain but a very good guess is the Daiwa /Shimano team has alot of imput into their design
The Cheaper rods ???
Well I dont think they give a sh*t to be honest it's all about being competitive on the market so to answer your Q ??
Who ever is selling the cheapest.
Most of the graphite is made in Taiwon for most of the rod building factories then it either goes to China for the cheaper rods or Malaysia for your more quality blanks destination of graphite will determine quality of blank.
Good example is some of my rods I have various types cheaper Viva Graphites which are pretty good considering the money you pay for them now these rods are made cheaply winch's guides are a dead give away & no different to the same price range Daiwa's/Shimano's in fact the Viva are better value cause you're not paying for the name & who knows they may even come out of the same factory cause Viva dont build rods no different to the rest of the Reel Manufacturer's
Then there's my Browning Rods ! completly diffent class of rods, Supirior Blanks to the viva All have the Fuji guides/winch's etc but again they are much much dearer, you get what you pay for, these rods come from one off the higher class rod building factories & are quality.
Now all those Blanks you've seen me building up in the rod building threads ??
Well they're all whats called A RAP blacnk full graphite & those who've been out in my boats will vouch what a nice rod they are & one of the reasons I thought this thread would make for good reading.
I wanted to see how many are still using the old glass rods & how many have been converted to a nice ghaphite rods.
In my books there's no comparisment once you've used a graphite rod you'll never pick up a glass rod again & I'm not just refering to spin rods either I'm using graphite for all my bait rods as well