Help with Ted Pella blade purchase

[Radman]

I have found that I like the blued Pal blades more than the coated stainless....I know go figure but I can get a lot more mileage out of the carbons. I buy the 10 packs for around 4 bucks at IGA. Which Ted Pella blade is the one that matches.......would it be the 121-20?

thanks,
Greg