Why not if the tubing is thick straight gage? And the "rigid" fork is prolly steel. My VISP frame is heavier than most cromo frames. And maybe the cranks and rims and bars and seatpost etc are all steel. Those $2 tires are probably about 2 lbs apiece. An so on. So yeah, I can see 40 lbs.

Last Xmas I put together some el cheapo Xmart bikes for a friend's kids and those things were like lead sleds. The wheels were so out of whack that they were rubbing on the frame and fork and the brakes could not be adjusted to where they would apply any force with the levers pulled all the way to the bar. Not only were they total unridable POS's, they were very dangerous POS's. I did my best to render them rideable. Fortunately, the kids quickly lost interest in them before they hurt themselves.

So the moral of the story is if you buy some really crappy cheap bikes that don't work no matter how hard you try to beat them into submission, you've just wasted your money, no matter how little you spent.