Hiya, what steel grade/specification is generally used for brackets like Batwings, shackles , spring perches, ladder bar or spring and shock brackets on rear axles, ?? What grade of steel are you using for chassis tubes and chassis building ? Thanks, david
It depends on the car, and the part. Most street car stuff is mild steel, but race car stuff is often chrome moly steel.
Thanks squirrel, I use mild steel everyday to build gates and fancy iron work but wouldnt use it for a car, I was asking for steel grades for hotrod uses,
Like I said, it depends on the "hot rod". Is it a race car, that needs to be as light as possible? that's generally what higher grades of steel are used for. Chrome moly tubing can be quite a bit thinner than mild steel, and have the same strength, so it is often used for race car chassis and roll cages. Race car suspension parts are usually made with stronger, thinner material also. But most street driven "hot rod" stuff is mild steel, and it's thick and heavy.
Yep I try and use cold rolled steel. ^^^^^ I don't own a genuine race car ( well sort of) and for tubing as in roll bar tubing I will use DOM but it will still just be mild steel.
Im asking because i will need to convert grades and find an equivalent french grade, Example; mild steel Dom tubing, or plate steelfor brackets. there must be loads of different grades,
Here there are different grades of steel but what you can find without shopping for exotics is Mild steel in hot rolled or cold rolled. Cold rolled you don't get all the mill slag that you get on hot rolled. The deal with DOM is that it is more consistent than common tubing. So if you buy for instance 1"x.125 DOM you get .125 thickness all the way though. Common tubing you will get variances in wall thickness. Jim ( @squirrel ) uses Chrome Moly steel because like DOM tubing for example it is more consistent and you have the added benefit of being able to use smaller diameters and wall thicknesses to get the same strength, so you can built it lighter. It is a little harder to work with but once you know how it is as easy as anything else that must be built to spec.
In US, SAE 1020 is typ. Low carbon mild steel. Easily worked, formed or welded. The final two numbers tell the amount of carbon, in 1/100ths of percent. So: 0.20 in this case.
here is a quick guide...with detailed specs of a few common grades. http://www.onlinemetals.com/productguides/steelguide.cfm
Unless you get "mill certifications" when you buy steel, it's all A-36, or should be considered as such! Many(most??) of us raid the 'scrap-pile' for usable pieces for our projects(unless, as noted above, for racecars): just be careful to 'file-test' or grinder(spark)test to have some idea of the actual grade of steel you are working with, as some of the High Carbon grades can be difficult to work with unless you are used to using them!
If doing body panel shaping/patching, use #1008 A-K steel sheet. ('Aluminum-Killed') Ronny Covell told me about this in Santa Clara around 1978. 'Brand new' then...
I see your point in that in France you may need certain specifications for the steel you use to fabricate a chassis from scratch or fabricate certain parts. In that case I would go with what the specs there require. Most of us home hobby hot rodders here do just as DrtrcV-8 said in post 12. We go to the local supply yard or fab shop that sells remnants and buy cut off pieces out of the pile or bin to make small brackets, gussets and what not out of for our hot rods. If you are lucky they toss it on the scale and sell it to you by the pound at a bit of a reduced rate over what it would cost to have it cut off a full stick or full sheet. The place I usually go to has a fabrication shop that makes specialty truck beds and trailers for agriculture use including feed trucks and manure spreading trucks and trailers. They always have a stack of freshly cut pieces laying in a pile on the floor in the steel room for people to pick from along with racks of steel tubing and rod and racks of sheet metal and expanded metal. Most of the hot rodders in the area for 20 miles around pick pieces out of that pile for their hot rods. Those needing special spec steel either go to another and larger steel yard and buy or order it. Outside of building a chassis/roll cage for a race car that is going to be raced were you either want the higher grades or rules require it with prof we normally don't as Jim said use the special grades of steel and go with the less expensive and slightly heavier mild steel.
Must be good steel you get coming from the trailer makers bin, I use black mild steel everday for fancy iron work but you wouldnt want to useit on chassis parts, I just needed some grade numbers for something more suitable because i dont know and no one to ask in my region, Road chassis making and modifieing is ilegal in france unless its purely race stuff , then its chrome moly or equivelents, I just need "good" steel grades to make batwings etc, Thanks again hotrodders
Man i feel sorry for you guys over there. We can just cut up an old bed frame to make parts with and nobody gives a hoot.
The A36 designation is officially specified as ASTM-A36 (American Society for Testing and Materials). Mild steel is a generic term for many grades of low-carbon steel. Any of A36 or "mild steel" will be fine for your purposes, assuming you build it sufficient thickness and bracing. Cold rolled is just a nicer surface finish than hot rolled, strength is the same between these for the same specification material. Get cold rolled when you can.
Look up steel in Mc Master Carr's site. They have a pretty good section that explains types of steel and the uses for them. https://www.mcmaster.com/#standard-steel-sheets/=1camhj3 I like their 1045 alloy if I have to buy something, I usually have a lot of leftovers from paying-customer jobs. Been working on a few lengths of 1/2" x 4" hot rolled steel bar for some years now that someone gave me. It machines and welds nicely.
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