Double layer metal tubing

[nnam]

This came from a piece of furniture. The only reason I can think of that they did this is to save stainless steel. So outer layer is thin stainless 0.1mm.

Usually doing this is hard, and manufacturing it would cost more. But they probably master the manufacturing process and as a result it saves them money.

The 2 layers mated so well it is hard to know they are 2 with no glue in between.

 

[markba633csi]

I'm guessing the inner layer is plain steel? Likely done for cost reasons as you surmised

 

[Mitch Alsup]

Double butted Reynolds 531 tubing was used to make racing bicycles prior to carbon fiber. Lighter but almost as strong.

But in this case, just a cost reducer--likely brazed or press fit.

 

[francist]

This is pretty commonplace on things like brass bed frames, torchiere lamps, etc. Not so much the old ones — they were usually solid alloy tube — but the new ones are very often just skinned or wrapped in the desired “show” metal.

 

[Eddyde]

Recently I was given a lift pedestal from a veterinary operating table. It was basically two telescoping square tubes containing a hydraulic jack. At first I thought it was solid stainless steel but upon taking it apart it was in fact, stamped & formed stainless steel sheet, over aluminum tubing. I thought it odd as it was obvious there were quite a few bits'n pieces and manufacturing steps involved, in pulling off the subterfuge. The stainless parts were screwed to the aluminum with many small screws, trim pieces, etc. I thought, why not just use two pieces of square stainless tubing and be done....

 

[Aukai]

My old Mossberg shotgun was SS plated.....

 

[francist]

I wonder, in the case of everyday consumer trash like a lamp pedestal or something, does the practise allow them to advertise it as “solid” whatever tube? I mean, it is indeed solid metal and not plated, it’s just very thin solid metal tube. Kind of like the “real leather” belt you buy — there is real leather except it’s only about a micron thick and glued to an eighth of an inch of compressed cardboard…

 

[markba633csi]

When labor is cheap one can do all the extra steps and still be profitable "pulling off the subterfuge" as Ed put it
Take the fake Mitu calipers for example...

 

[Jake M]

I wonder, in the case of everyday consumer trash like a lamp pedestal or something, does the practise allow them to advertise it as “solid” whatever tube?

I don't know if it's "allowed" to be called solid, but it's commonly done. Most recently in my world, BBQ grill grates and a utensil set from different manufacturers. (Same store). Two months, it was obvious that the plating was coming off of the utensils. (I leave 'em outdoors). Normal plating as you would expect. Six months, an unreasonably thick outer layer (thirty or 40 thousandths maybe? on rods that are in the neighborhood of 10mm/3/8 ish diameter) started chunking off of mild steel bars here and there. Boxes and store reciept said "solid". I went back with the utensils first, no eyebrows were raised, and I was recommended not to exchange those utensils for another brand, because "they're all like that". Cool... Hassle free. The best a store can do I guess in this world where they don't even know what they're getting..... I went back months later with the grill grates, way out of the return period, They were darned near a hundred bucks, and it's not really "warranty" at that point. It's flat out not what I bought. Worst they could say (and I'd have probably accepted it) is that it's been too long. No questions, "Don't even worry about it. Exchange, Refund, Store credit?". Again, they've clearly seen that complaint before.

I've got a vacuum cleaner with a stainless steel handle. Eight or ten years old. When I removed the plastic handle at the top of the main handle to diagnose a failed switch (it wasn't the switch), the inside of that stainless tube is pretty solidly rusted. Stainless steel cofffee maker? I dunno (and it isn't conclusive), but a magnet sticks hard to it, not just kinda stuck like the magnetic stainless I'm used to seeing, but there's a lot of nuances to that that I'm not familiar with.

Yeah, somebody's figured out how to save a buck. And/or not save a buck, but guarantee something not to last forever. That can't be cheap putting all this stuff together like that. The only savings is the DIFFERENCE in cost of some fraction of the material. They saved all that stainless, but they had to pay for the "not stainless". Which drops the volume of both, which has to effect the economy of scale pricing. Although I'm not sure if retail pricing relationships are directly carried over to bulk wholesale when you're buying stuff by the train car load.

Grrrrr.

 

[mcostello]

I think sometimes manufacturers make things as cheap as possible then sit around while They are drinking a brew and laughing about it. We are Their entertainment.