A Few Things You Should Know About Cold-Rolled Steel

[@billshiff2060]

It's not only in the "skin" , it is all the way through to the center. The worst case is when you remove material from any lengthwise axis and cut to the center. Like if you mill a 1/4" deep pocket on 1/2" CR it will cup so badly it will be useless.

[@eclear4evr]

That's crazy. It's like tree grain if the trunk or tree was underpressue when you cut down, then you release the pressure when milling/cutting. Wow! Fascinating!

[@dannyolivarus1801]

Something we are loosing today is good steel, die and lathe workers. I'm grateful to be educated this way. Your video just taught me alot.

[@SuperSwitched]

Wow! I've been machining for 40yrs and that is the first time I have heard of this. That being said, What I did know was to always use a piece over size for the project and machine all faces. The advantage of CR over HR was less wear and tear on the tooling due to slag. Some good questions/response here Phil, please do a follow up! You merely let the cat out of the bag :)

[@mvpmachine]

Run into this all the time the imagineers are not taught this in school. I have customers that want clevises in tight tolerance military and aerospace parts and they supply cold rolled. I leave tons of stock and creep up on the numbers with a fly cutter with a reversible bar. A lot of extra cuts when hot rolled would have been just fine. I do like cold rolled steel for a lot of things but you have to know the limitations. Good video. Cryo treating prior to cutting makes a world of difference with stability but not a commonly used practice unfortunately.

[@fall22123]

I run into this problem a few times a year where I work. The way they do things, I get the work order and the material delivered to me. It's already too late to ask for hot-rolled. I think I have the saw dept trained to spot this now. Anyway if you stress-relieve the material before you start machining it, you'll be fine. For me, it's as simple as sending it to the heat treat dept. You can stress-relieve almost any material, even tool steel. You're right, you can drill holes in it all day. As soon as you cut the outside skin off, it curls like a banana. If you manage to get it flat again, it can continue to curl.

[@Sandarpan]

By heat treating it. Annealing.

[@shichae]

Thanks for this video. You mentioned that the scale on the surface created tension within the CRS, would the dimensions of the part still change post machining if one were to remove the scale and then bring the part within spec?

[@torbjornkrondahl8116]

Hello good info there is not many people know this. My name is Tobi and comes from Sweden I work with high presition components that I do in our CNC machines., I often make rough first and then let the subject rest 5 - 10 days before the finish cut. And it works fine.

[@pierresgarage2687]

Hi, Agreed, in just about any material, most of the rough cuts should be done prior to finishing, specially cold roll...! Pierre

[@OldIronShops]

Boy that's good information

[@timmallard5360]

Great tip phil! This is the kind of stuff they don't teach in engineering school. Makes perfect sense. Thanks for passing on your knowledge.

[@littleworkshopofhorrors2395]

They don't? That's unbelievable!

[@unionse7en]

@@littleworkshopofhorrors2395 They may or may not, Engineering (like most disciplines is vast), can't cover every topic. The MOST important thing they DID teach me was C.Y.A/ Cover Your Ass..lol.That's why Engineers are so anal...don't want to commit get burned before going into production. Never ASSume. Research and test before commiting. For sure similar "gotcha" examples are provided in school...so a wise person will extrapolate and always wonder what they DON"T know about a thing, even if not specifically taught ;-)

[@justinclark9258]

Hang out in the machine shop and you'll learn it. They also teach it in manufacturing class.

[@hakimmic]

Thank you for that tip.That explains why some larger internal parts I would make still require stoning and fitting. And it's because the metal flexed or warped during machining.

[@ronrogers4523]

HI Phil. First I have to thank you, I know this is an old video but again I sincerely feel the need to say thanks . After being 40+ years deep in the trades, I so appreciate it when someone can give me a head slapping uh-ha on goes the light bulb moment! How and why did I not know or figure this out? You are so correct, this just answered some head scratching moments of the past (What happened to this part, how did these reference edges end up out of square??) I just found your channel and look forward to viewing more of your work. Hope you and yours are keeping safe and well in these crazy times. Cheers and best regards, Ron.

[@ImJohto]

Good to know. I just started my apprenticeship on the 3rd of this month, so I’m constantly looking for new things to learn. Definitely gonna keep tabs on this channel.

[@PrimitiveBeasty]

I knew this would happen if you just removed the skin on one side and not the other, interesting to learn that even removing some from both sides will warp it. I think I read somewhere you can avoid this problem with cold rolled by stress relieving it first, although you kinda have to go out of your way to do that.

[@buddylineman]

Thanks, I did not know that. I enjoy learning something new. Buddy

[@steveprice5664]

I machined some CRS round bar on my lathe today. I had a very poor finish until I got into it about .050", and even then It wasn't good. I could definitely see a difference in the chips coming off. I thought it might be caused by something like this. Thanks for letting me know I'm not crazy after all. (Well, may I am...)

[@forestherzog9525]

What if you anneal it? Say, cut your reliefs out first and then normalize it and then machine to spec

[@frankbonsignore.RochesterNY]

Wow! I never would have expected that. Thank you so much for sharing this experience!

[@lowridingtrucks88]

Thanks for the info. Its sucks to surface grind it also.

[@427zoh6]

Five stars for you! Thanks, I'm a amateur machinist been doing it for a long time but, learned something new today. Thanks!

[@siggyincr7447]

If you're trying to hold tight tolerances, CRS isn't a good choice, as you noticed. But if you do need to do it, stress relieving will eliminate the stresses that cold working the material introduced. Then you can mill it without having it go all over the place.

[@larryschweitzer4904]

Thanks, I'm just a hobbyist in metal & didn't realize that there would be that much stress in cold roll. Make sense though. I'm surprised that hot roll would be stable. I retired from manufacturing commercial interiors, wood based. There are lots of issues with wood stability. Having had lots of equipment with cast iron parts I was well aware of how much stress that stuff can have and move after machining.

[@Sketch1994]

In my experience from making sample fixtures from cold rolled square stock or flat stock, it almost always starts to bow towards the side you are cutting, as you are removing the layer that had it's grain irregularities forced out. It acts like a fabric bag tightened thread by thread around the softer and elastically compressed core. Everytime you cut a thread it affects a certain length of the fabric.

[@miles32323]

I'm in machine tool technology right now and one of our projects is to make a parallel out of 1018 crs and everyone's part came out of the vise with a bow to it. CRS has a nasty tendency of having pent up stresses made into the material. Great video!

[@phillstevenson4931]

what i do is have all my finish ops last have a stop in my program, release the vise and then tighten it again, take all my finish passes, seems to work great

[@wiredodger60]

What about pre heating and static cooling to relieve the cold rolled stress then milling or will you have the same results. Great info.

[@tubester4567]

I think you will have the same problem with hot rolled mild steel too. Not to mention, hot rolled mild steel is usually warped, like a 12mm flatbar will be concave on one side and convex on the other. I would have told the customer if he wants that kind of accuracy, he needs to buy a tool steel., Or at least look at getting cheap steel annealed before machining and machine all the faces.

[@argentorangeok6224]

One of my first embarassing mistakes with cold rolled anything was a piece of 304 I needed a shoulder milled on. I could not believe how much that piece of steel curled up. It looked like it had been heated and bent.

[@earthjin2000]

Awesome info...Added it to "things I should know but i don't" list.

[@johnw4590]

I wonder if you reheat the piece to a determined temperature would it neutralize?

[@ww321]

I remember building change parts for case packers from .5"x2"x24" it would bow 1" sometimes.

[@TheToolandDieGuy]

The machining process doesn't matter. Once you start carving it up, it's going to react. But I do understand your comment, as wire EDM isn't quite as abusive as milling.

[@aryesegal1988]

Amazing! Didn't know that, I learned a lot! :) Couldn't you remove the entire skin (face it flat completely) and then to the cutting? Or it still wouldn't matter, this "effect" will happen in any depth of the material?

[@mattymcsplatty5440]

just found yr channel randomly, yr channel is a great, love yr vids

[@daxshell242]

as far as machinists go... your finger tips are beautiful.

[@gaildimick1831]

Thanks for the tip.

[@janvisser2223]

I had a problem with porosity in a filletweld after stickwelding a cold rolled hexagon nut.

[@ryanb1874]

Love the intro music

[@viperkill3]

Try and annealing it before putting it through the cold rolls..just a thought...I run a cold rolling mill so I get what you're saying

[@richardknight1841]

Thanks for the heads up. Hot role it is.

[@hu5116]

Thanks for great vid! I have watched bunches of machining vids, and although thy might mention this or that about THAT were using CRS or HRS, they very rarely ever mention WHY? You have done that. Now my question is why would anyone ever use CRS if it warps like this? A comment mentioned about MIL scale being bad on tools (agree), but that is what vinegar and hydrochloric acid are for. Maybe if you just want to start with something that is reasonably dimensionally the side you want already and you only want to do a few things to it like drill holes maybe CRS has a slight advantage. And maybe also if you don’t care if it warps. But otherwise HRS seems the only way to go (or annealing the CRS, in which case why not just remove the MIL scale with acid: about the same effort and inconvenience). Sounds like a good video topic!

[@creativebobbo]

Good sound effect

[@cogzoid]

Is it possible to anneal the steel and reduce those internal stresses beforehand? Of course, that's not always feasible, but is it possible?

[@zxwmabcdef5439]

Was it Curtis Steel brand? I think they shove it through rollers as fast as they can and they don't anneal it to take the stress out. We got a load of 1/2" and 3/16" plate and .075 and .048 sheets from them. All of it was oil can on the pallets. We couldn't do anything with it except throw it in the scrap barrel.

[@metaling1]

Thanks Phil... I agree with SuperSwitched - please answer some of those questions below!

[@TheMudfly80]

I understand that it will spring due to temperature variation or being cut, but will it even just move over time even if the temperature is relatively constant?

[@priority2]

Wow! Excellent info,thanks 👍

[@harleyghost]

Wow, thank you for the tip.

[@Darkeiser.7]

Had no idea. Thanks.

[@oceanflyer7078]

I learn so much from your video, thanks

[@RWCSNZ]

What about cutting cold rolled steel on the lathe? could this give me an excuse? For some reason I thought cold rolled steel was better than hot rolled for cutting and accuracy (it's normally pretty uniform straight off the shelf).

[@burly_girly]

Great info, I didn't know that crs did that, thaks for the tip!

[@moretimethanmoney8611]

How does this translate to using cold rolled to turn a shaft of multiple diameters?

[@kenibnanak5554]

I think this is a major thing for the unwary. I hadn't known this. However, if it is a stress issue, can't it be heated to temper around 450F to relieve the stress?

[@haroldkreye8770]

If cold-rolled steel is annealed before machining, is the movement problem removed? Thanks.

[@mattpiehl7122]

Whats speeds and feeds do you use to mill that cold roll? I need to mill a .26DOC and .375 WOC?

[@RequiumFrost]

awesome thank you. Im here because i heard the term cold rolled steel from game of thrones the other day regarding there gate defense (4" Bars).

[@SevenDeMagnus]

its this hard, strong or tough? Is it stronger or harder or tougher than forged steel? God bless.

[@jcw47352]

What happens if you make your cut outs first then mill and the edges/

[@skypimp3409]

Thank you

[@jennynorrby3030]

Thank you! Very useful information :)

[@TARASGUITARS]

Thanks.

[@jonarbuckle1560]

Couldn't you normalize the batch in an oven. I'm seeing a lot of tempering numbers being put out, but that thing needs to be normalized from a bit below critical range imo Any thoughts?

[@2007markb]

Thanks for the good info phil. Too bad you got bit, but it happens sometimes

[@herbender]

that's also why you can never mill down parallel keys, if you need a stepped parallel key or a modified one and you think you can quickly mill down an existing one, forget it the thing will go crooked like a banana

[@jasonburns1407]

thanks for sharing

[@mattymcsplatty5440]

is the 5/1000th out of spec due to stresses akin to cutting a ring of steel and it springs apart?

[@literoadie3502]

Hi there, I'm a newbie to machine shop and bought some hot rolled plate online to do some layout work with a permanent marker as layout blue. I found the mill scale to be a huge annoyance when trying to scribe layout lines, do you think cold rolled would be a better choice for making parts by hand with a hacksaw and files?

[@frankbonsignore.RochesterNY]

Hi Phil. Thanks for sharing. I've got a newbie question: why did you climb mill first and then conventional mill as opposed to the other way around? I thought that climb milling left a better finish. Just asking, not challenging.

[@TheToolandDieGuy]

Conventional milling will take any "spring" from the endmill away, thus giving you a straighter cut. This is much more notable on a side cut that is 3" deep vs. 1/4" deep.

[@hdoug5]

thanks for the great info :)

[@duanedickey7043]

Is there a cold roll that is less apt to do this? And what is a good hot rolled to use? A36?

[@kittxgor]

Apologize for commenting to an old video but I'm buying some 36mm bright steel round bar tomorrow. I need to machine some of it down to 35mm. Is this stuff cold drawn ? and if so how will it handle going on a lathe? I need it straight!

[@Solingen1000]

that's pretty neat.

[@deweys]

What if you mill off the surface?? Does that release the booinnnggg?

[@TheToolandDieGuy]

YEP

[@gaildimick1831]

Oh! And you can’t beat Mancini.

[@Wjones450]

just curious, what if you milled the shape and then squared up the ends? same problem either way? moral of the story, just use something more stable

[@rsstnnr76]

Learning about the cybertruck brought me here.

[@corwininadsm]

I bet the Tesla Cybertruck will have problems with body panel's staying uniform. But who knows.

[@febeomnibeepboop6367]

Lol the rage. very informative

[@LTDANMAN44]

I came here because i was watching an 80's wwf wrestling match and randy savage hit champion tito santana with a piece of "cold rolled steel" and knocked him out. I needed to find out what that ment

[@769elloco]

how about Wire EDM it.

[@MrWoodchuck59]

Mill it, normalize it, grind it, ship it!

[@ryanb1874]

Will that spring it back ?

[@MrWoodchuck59]

@@ryanb1874 Normalizing steel heats it up and it will equalize the grain structure to remove internal stresses in the material. If you only take a small finish cut it will be stable enough that it will keep it's finish shape & dimensions. It is quite a technical process, Each material and part will have its own temperature, soak time & cooling time. Grade and size. Temperature is critical, you can't just guess at it. www.forgemag.com/articles/83798-the-importance-of-normalizing

[@edwardbelfiglio7299]

That steel is not COLD ROLLED - It is Cold Drawn!!! Cold rolling applies to sheet, strip and plate because it's made in a Rolling Mill. Cold Drawn steel is produced by processing a hot rolled bar (round, square, rectangular, trinaguler, hexangluar, octangular and many other shapes) by pickling the hot rolled product, coating it with a drawing lubricant pointing the end, pushing it through a carbide die and then putting the rest of the bar through the die. This process produces close tolerance shapes with good uniformity of cross section. The generally used term CRS is a misnomer!!!

[@frenchcreekvalley]

Yup. Annealing or normalizing is your friend.

[@JackmeriusTacktheritrix-000]

Here because of Tesla Cybertruck

[@thunderbirdone8126]

Use stress relieved steel instead of CRS

[@TheDaken]

try annealing the steel first before you machining the surfaces.

[@pakman422]

The stresses need to be relieved first by soaking it at its critical temp. This is called normalizing

[@franklinblazek25]

I was thinking the Same thing if you normalize the material and let it cool slowly I would think it would help a ton. Has anyone tried that approach?

[@josecanedo007]

@@franklinblazek25 it Will become hot roll, and believe it wasn't what the customer requested.

[@anthonyjones657]

Only way I've ever seen it work is to cut all side then finish machine

[@ammagato]

Troppo prolisso nelle spiegazioni, la soglia dell'attenzione si perde nei primi minuti di video, questi sono dati scientifici.

[@fotografodefotos5564]

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