Sheet Metal - Which One is for Me?

OK. So what are the options, each with full material specs? Post them individually as separate posts and let CR4 users use the Good Answer buttons to vote for the best ones. That's the way that opinion polls work around here. Especially if prompt replies are a priority.

I am seeking options. have no clue about other options. any one from sheet metal fabrication/manufacturing field could guide me better.

Well, what is in use at the moment, and why is it no good?

Please give the forum some information to work with!

Currently i am using ASTM A36 sheet. Most oftenly it shows some deflection in finished product. i have to compansate it by adding some ribbing for support which is ofcourse an unnecassary cost.

I will give you one practical example. let my finished product is one cabinet whose hollow chamber has outer dimensions of 20" x 24" x 18" ( W x H x D). its three sides are closed and one side is open for inserting draw and cabinet door.

Well, how much distortion is allowable in sheet that size? Why not make it out of cast iron, for example? Or plywood? Or glass? Why not make it out of the same sheet steel, only thicker?

Does <...draw...> mean "drawer"?

If ribbing is necessary to prevent deformation, then it is not "unnecessary". -- JHF

You have defined Oxymoronic Unobtanium.

"should not have any deflection in it, but at the same time it should also have some deformability so i can bend it"

Quite.

You aim to please and your a damn good shot. I think I've said try different gauge for the application,as fastening will create deflection if he uses welding. Rib to strength is as you stated,James Cameron has nothing on you!

Neither James Cameron, nor I, would go to extremes to make a product as cheaply as humanly possible at the cost of functionality, quality, good taste, durability or aesthetics.

That seems to be the goal of many who come here, be it cabinets or coal fired boilers or construction materials or surgical instruments. These zealots all seem to come from locations we probably all could name, but won't.

The unobtanium wording was my reference,unfortunately quality has gone the way of cheap. Lighter castings, on autos,motorcycles,and appliances has all gone down in quality. Sometimes to the detriment,even the stronger metals are not specific in production to suit the intended purpose. It's hard to answer the question,when little information is given,use ect..

I know.

Tools, with a lifetime warranty, sold by a former Premier retailer, now owned by a discount Mart, are a good example.

I've got a set of combination wrenches handed down to me from my father that don't even look like the same tools as another set I bought 5 years ago. They still have the lifetime warranty, AFAIK.

Whenever I can, I buy stuff Made In The USA. Well, at least the paper label is.

Remember the USA city in Japan? Even some of the snap on new stuff can't compare to the old. Metallurgy has grown,how ever the quality and cheap labor all play to the equation . Specification writing has become an art,with ANSI numbers playing a very important part. Safety included,FM all the great testers have gotten fewer,regards Eric

Heat treating could be an option, if installed hot and allowed to cool and shrink it will be more rigid, but your design would have to withstand the tension.

Heat treating and quenching might make the original design more rigid but is costly and difficult to accomplish.

These reasons are why supports are used in long spans or thin metals. Your support could be additional material bracing or by installing a crease or v-bend.

The three main design parameters are good, fast and cheap (usually you only get to pick two). It sounds like you are concerned with the good or the cheap so either pay more to reinforce your product or leave it with deflections and a 'cheap' appearance.

Drew K

There are compromises here, minimum deflection you want strength, that would increase fracturablity........

Now you need to bend it, How much, how sharp a bend?

This you now have to give up strength for malleability.

Bit hard to say from the information supplied, but a lot of what the OP is trying to do is covered by proper design. The addition of swages, double folded edges, wire edging, and the list goes on. But as I have no idea what is being made, I couldn't begin to give a helpful answer. Large cabinets are frequently made from .9mm with no problems at all but it is usually down to the way they are designed.

You cannot change the stiffness of steel by getting different heat treats. Stiffness is related to the modulus of elasticity which is very similar in most steels.

Your best bet is to try your fabrication with some different thicknesses of sheet to see if your acceptable flexing parameters are met by using a different thickness.

You can also try the very shallow bending techniques used by sheet metal manufacturers to stiffen sheets. I don't know what the name of this technique is but you can see the bends in a flat sheet that look like the letter "X" across the rectangular shape of the sheet.

If you have a flat that cannot have any forming showing on it, like a table top, maybe your best bet is to add thickness here or a stiffener by tack or spot welding.

Jon.

It's called "cross-panning" or "cross-breaking."

Sheet should be CRCA (cold rolled closed annealed) these sheets are most suitable for steel furniture mfg. they have flexibility and taking different forms.

How you plan on joining is key,welding causes way too much deflection, 16-20-22 ga is all workable with a good break and shear. Planning to spot weld? Rivet? Try different pieces and then decide . Unless you have a spec submittal to meet

Ok, so you have the sides are you forming it the sides then welding the seams? How are you finishing the seams? If you are welding them then just weld a stiffener in side.

For the size box you are making, I don't see where deflection is an issue. It should be rigid enough for the size you're making. That 1.2 mm sheet is close to 16 gauge material.

Cold Rolled is more rigid than Hot Rolled. That thin it might be malleable.

Who was it that mentioned "Oxymoronic Unobtanium"...???

As I've stated elsewhere "As happens all-too-frequently... here is another thread racing off on multiple tangents with a whole lotta "guess-work" going on."

Must we ALL continue to JUMP ON THE GUESSING BANDWAGON, and plow forward without asking the most IMPORTANT questions ... "UNOBTAINING" some useful information FIRST...?

Neither (Shoaib's) 'OP" nor his Post#2 nor his Post#6 ("Currently i am using ASTM A36 sheet") offers us a single GLIMPSE into the *PURPOSE* of these cabinets.

My first thought was of flammables-storage safety cabinets, or corrosives-storage cabinets...

...whilest others seem to be ASSUMING "clothing storage" or just plain "furniture"...

How about it Shoaib ... are these for locking-up ammunition or WHAT (_^please)...?!

_{^{{"PS" --- Kudos to PW, for at least prompting: "Please give the forum some information to work with!"}} }

If your priority is durability, structural strength, and outdoor performance, galvanized steel is usually the go-to option. It handles corrosion well and is widely used in industrial and storage applications. Stainless steel, on the other hand, makes more sense when corrosion resistance and cleanliness are critical (labs, chemical environments, or long-term exposure to harsh conditions), though it does come at a higher cost.

Aluminum is often chosen for its lightweight nature and ease of fabrication, but it doesn’t offer the same impact resistance as steel. That’s fine for enclosures or panels, but less ideal for high-risk or heavy-duty use.

In real-world projects, sheet metal selection is often tied to the end structure, not just the material itself. For example, in industrial or hazmat environments, sheet metal is typically part of a larger system — insulation, fire-rating, ventilation, and compliance all matter just as much as thickness or finish. That’s why many facilities opt for pre-engineered solutions, like container-based builds, where the sheet metal is already designed to meet safety and regulatory requirements. This kind of approach is common in hazmat connex conversions, where the metal choice supports both strength and compliance see how it’s applied here: https://ushazmatstorage.com/hazmat-connex-conversion/.

My suggestion: start by defining use case, exposure (indoor/outdoor), load requirements, and safety standards. Once those are clear, the “right” sheet metal usually becomes obvious.

Stainless? Galvanized?

14, 16, 18 Gauge