Bicycle Mechanics - steel ratings?

I have seen different ratings for steel tubing on fugi bikes ,and same year bikes,does anyone know the quality rating for example 661?

carbon + iron= steel

661 what from which steel tube supplier?

its not a standard number like 4130
AISI assigned to a certain alloy of steel.
so it's a probably a brand name.

Fuji 661 is hi-ten 1020 tubing.

Fuji 661 is hi-ten 1020 tubing.
AISI Grade 1020 steel (aka Hi-Ten in bike speak) is one of the lowest cost and weakest of the multitude of available steel grades. It is used in the lowest cost and quality of bike frames and must have thick walls to be adequately strong. So frames made using it will be heavy.

Better and stronger steels include a range of Chromium and Molybdenum containing alloys (aka Cr-Mo) and even more exotic, stronger, alloys which, obviously, are more expensive. These can be made into much thinner walled tubes while maintaining adequate strength so the resulting frames are much lighter.

Of course to get strength in a product made with 1020, you use more of it.
thicker wall tubing.

thanks to all that posted ,you were very helpful.

Another thing to note is that there is no difference in stiffness between the various grades of steel-alloys. Just that 4130 chromoly is stronger than 1020 (it can take more load and bend more before breaking), so less of it can be used for the same strength. Thinner tubing will result in a lighter, more flexible and springy frame. That's the "liveliness" that's often talked about. On 1020 frames, heavier thicker-gauge tubing is used, and the ride is harsher and more dead feeling due to the stiffer frame.

I'm sure if I searched the site, I'd find answers the following but since this thread is just opened, I'll go ahead an ask. Are there functional differences I,as a rider, am likely to notice among the higher end options or is asking the question opening a personal preference can of worms along the lines of "shimano vs. Campy" . Columbus talks about niobium, themacrom and nivacrom with their various tubesets (life, foco, zona, etc) , while Reynolds with 953, 853, 631 etc, discusses stainless teal, heat treating and air hardening . Then there is Tru temper platinum OX whatever that is and whatever Tange makes. I am considering a frame made with Columbus foco (niobium --- main triangle) with nivacrom stays to replace a frame I had,which was Reynolds 631 with 725 stays. I am inferring that the Foco tubes from columbus are a bit higher up the chain that 631 (so will be a bit lighter and thinner) but really have no clue.

Edited to add: Nevermind, I did some searching and there are in fact 8 gazillion threads on this so I'll just read them

Simple answer: For the exact same geometry and size, I seriously doubt you could tell any differences among frames made with any of the higher end steels as they will all have similar tube shapes, wall thickness and weight.

Different steels have different properties that may be important to a builder, but not to a rider. For instance, Nivacrom® (with Nickle, Vanadium, and Chromium doping) is desirable because it resists burn-through during welding better than others. That makes it easier to use thinner butts at the joins with perhaps a lighter overall frame, but to a manufacturer the lower incidence of waste is at least as important.

in my experience, you can't go far wrong with a well-made frame composed of high quality steel. That being said, even 4130 bikes and the like are a lot less gruesome than you might expect. I wouldn't get too hung up on labels, and worry more about fit and the suitability of a frame's design to your needs.

-rob

in my experience, you can't go far wrong with a well-made frame composed of high quality steel. That being said, even 4130 bikes and the like are a lot less gruesome than you might expect. I wouldn't get too hung up on labels, and worry more about fit and the suitability of a frame's design to your needs.

Cheap bike - fits the only thing. If it fits, buy it. Don't worry about all that other stuff.

Expensive bike - fits still the most important thing. If it doesn't fit, don't buy it.

Cheap bike - fits the only thing. If it fits, buy it. Don't worry about all that other stuff.

Expensive bike - fits still the most important thing. If it doesn't fit, don't buy it.

Well, i think the suitability of the design to your needs is pretty important. If you find a roadbike that fits like a glove, it won't do you much good if you're looking for a mountain bike. But, fit is key. Even if EVERYthing else about a bike is perfect, if it doesn't fit, don't buy it.

-rob

The better Fuji frames were also Triple butted and quad butted in the early 80's. They also made a true touring series 3, 4, 5 models of bikes and some real race geometry framed bikes as well. I loved to sell their bikes back in the day. The team or club Fuji was my favorite