Gosh I feel dumb for asking this question.

Is there some sort of secret code that tells you if a frame is say steel or aluminum?

For example, on the Cannondale website I see nothing that tells me if the T1 is steel or aluminum:

https://www.cannondale.com/usa/usaeng...8TR1-Touring-1

under specs for frame is just says 'Touring.'

At the Fuji website the Touring bike has the same issue. Is it aluminum or steel?

https://www.fujibikes.com/LifeStyle/C...s/Touring.aspx

and there are plenty of other examples I could provide.

Now I know I can find the answers by searching (the Cannondale T1 is aluminum) but it seems there should be some simple way of telling right on the spec sheet.

Am I missing something?

The quickest way I know is to look at the shape of the tubing.

You just won't see skinny aluminum main tubes anymore. Maybe some old Al frames, but builders quickly realized that they were flexy and less durable, so they moved to fatter tubes to gain rigidity. Aluminum is also often formed into varying shapes, although it's sometimes hard to tell from pictures -- I'll bet that the Cannondale's downtube is slightly oblong vertically at the head tube then widens as it meets the bottom bracket shell. I haven't noticed a steel frame with shaped tubing.

Just by looking, then, the Cannondale looks like a typical aluminum frame, and the Fuji's steel.

As far as the spec sheet goes, if it's aluminum, it'll say something like "6061 alloy" or "7005 alloy" or whatever -- the key word is likely to be "Alloy". Steel, if it's not referred to as "steel", it's "chromoly", or "cro-moly" instead.
https://en.wikipedia.org/wiki/41xx_steel

The Fuji spec list says it's a Cro-Moly frame, i.e., steel.

I think that Cannondale site is the first time I've ever seen the frame material not listed. Weird.

thanks for this info.

Cannondale has NEVER made a steel frame. Some carbon fiber, and steel forks, but never a steel frame.

Like DD says, Cannondale made its name in the industry, making aluminum frames.