Grade 60 rebar is 50% stronger than grade 40. The grade indicates the minimum yield strength of the steel in 1000 psi or ksi. Grade 60 = 60,000 psi, Grade 40 = 40,000 psi.

I'm using grade 60. I didn't have any problem with 5/8" grade 60 for my footing dowels, but I did cut the rebar with a chop saw rather than try to shear them off with the cutter on my rebar bender.

I'm using LiteForm ICF as well, but I haven't started stacking any foam yet. I'm using the 2.5" thick LiteForm Xtra planks. I've watched several basements formed and poured with it around here and didn't see any problems.

Grade 60 is stronger than 40. Yes, 40 is softer and thus easier to cut. However, you will need to look at the prescriptive tables or engineering to know what is structurally required. The cost of grade 60 seems incorrect. Unless, you supplier doesn't stock a 40 grade and it costs them more to bring it in.

Not here to knock a ICF system, however, Liteform has a couple of types of systems. They are generally known in the ICF industry as one of the forms that give installers the most grief! I haven't installed it, however, I have spoken recently to an installer than has experience with 12 other systems and he told me that it is the worst of all systems. He indicated that he charges quite a bit more to install Liteform.

If his customer insists using it because it's cheap (initially) by the time you add the additional labor factor to install it correctly you would have been off using a better system. You will need a lot more bracing and even then good luck holding to your dimensions with out a bowed and wavy wall.

Bottom line, how much less are they when you look at the bigger picture!

Double check the price, but it may be correct. When I was building my house the rebar supplier, I think it was, said that 1/2" grade 40 isn't actually being produced, that it is all grade 60. Grade 40 is grade 60 production that didn't meet the standards. Your rebar supplier may just have a lot more 60 in stock than 40, hence the lower price for 60.

Along the lines of ICFInstaller... Some blocks install for a dollar less (or more) per square foot than others. In some cases - the difference can be significant. I would avoid grade 40 rebar -- incorrectly priced or not. Regards.