Machinable steels - 1144 vs 12L14 vs..

[Jersey Tom]

I've turned 4130, 4340, 1018, 303, 304, 416, Invar, blah blah blah. Found some 'Leadloy' (12L14) layin around the shop the other day, figured I'd give it a shot.

Holy crap. It machines like butter. No, seriously. Just for kicks was taking a .075" DOC on a Hardinge HLV at 400ish RPM and 30 feed. Pretty good finish, and not a hint of heat discoloration on the chips.

Needless to say I'm using this for as many of the machined steel parts as I can this year! FYI, its got lead in it (hence the L) to increase its lubricity and machinability.

Also heard that 1144 ('stressproof') is pretty machinable with its addition of sulphur. Anyone turned this stuff? Pretty decent or what? Might be nice for some tooling with the higher carbon content.

And then.. McMaster I found out today, carries 41L40. That sounds badass.

Experiences, anyone?

[Jersey Tom]

I've turned 4130, 4340, 1018, 303, 304, 416, Invar, blah blah blah. Found some 'Leadloy' (12L14) layin around the shop the other day, figured I'd give it a shot.

Holy crap. It machines like butter. No, seriously. Just for kicks was taking a .075" DOC on a Hardinge HLV at 400ish RPM and 30 feed. Pretty good finish, and not a hint of heat discoloration on the chips.

Needless to say I'm using this for as many of the machined steel parts as I can this year! FYI, its got lead in it (hence the L) to increase its lubricity and machinability.

Also heard that 1144 ('stressproof') is pretty machinable with its addition of sulphur. Anyone turned this stuff? Pretty decent or what? Might be nice for some tooling with the higher carbon content.

And then.. McMaster I found out today, carries 41L40. That sounds badass.

Experiences, anyone?

[J. Vinella]

I experienced lead as a young boy, but I have forgotten most of those years due to the adverse effects...wait what are we talking about?

How much more does the stuff weigh? Lead isn't exactly carbon fiber.

[Jersey Tom]

Its only ~.2% lead. Weight is the same.

Apparently on a machinability index relative to 1212.. 1144 is 83%, 12L14 is 160%. Most low carbon and low alloy steels are 70-80%.

[fade]

ive heard its prone to rusting

[J. Vinella]

Is yours hot rolled (Yield 34100psi)
or cold drawn (Yield 60200psi)?

7075 yields at (73000psi)

I'm just wondering(besides cost) why would you use this over 7075?

I could see if the part needed to be welded but still you are taking a huge drop compared to 4130 or 4340.

[Jersey Tom]

For anything that's going on the car and is taking any load is go with CF material.

Yes, steel in general is prone to rusting..

Why would anyone use steel over aluminum? Hell, 4130 in its normalized state yields at around 60ksi. 7068 aluminum yields at 90ksi.

Steels tend to be harder, more wear resistant, stiffer, and the big thing - hardenable. Even if its 60ksi normalized, although .14% carbon isn't much I bet you could quench and temper it up to 100ksi or better.

I plan on using steel centerlock wheelnuts, rather than aluminum. Don't want that crap galling, and machining it so after anodize the threads still work is HARD. So, I'm using screw machine stock (12l14) which should be better for the application. Might even harden it up some, who knows.

[Erik Whoa]

You can heat treat 4130 to a 160ksi yield strength. It is VERY strong.

[Conor]

Jersey Tom,

How expensive is 1144 ('stressproof')? We're stretching our axles this year (chopping and welding the spline ends into a hollow tube) and I've been thinking about using stressproof. I would use 4130, but we won't be able to heat treat our axles so I'll have to have something that's tough without a heat treatment. We just found out today that we can't heat treat because we're using axles from an ATV and the outboard CVs are not rebuildable (there goes our great idea of building our own custom solid shafts). Because we're welding to the stock shaft, its material composition will basically determine our material choices, but I'd like to know a little more about stress proof.

[Jersey Tom]

Ooooh that sounds sketchy not gonna lie.

1144 isn't very expensive. 1" Dia is like $17 for 4 feet.

You're welding together two different types of steel, you're going to have a weld with a yield of maybe 70-80ksi and then the HAZ will be hardened to Rc55 or so and have a brittle martensitic microsctructure, with the rest of the shaft normalized at best. And you're gonna put all your drive torque through that? I would not. Fatigue loaded highly stressed weld in high-carbon steel. Heat treat it after you weld it!!! Find a way.

[Conor]

Dude, I know your concern, but it's our only route. The CVs cannot be torn apart and thus, we cannot replace the axles. The CV and axle are one. We're getting a full material analysis done on the stock axle material and will be choosing our well material based on that. I have no idea how to heat treat a CV without ruining it though.....

[PPAM20]

1144 and 12L14 machine beautifully but their heat treat (hardness) properties are not good even for a case harden. The important thing is welding is not recommended especially for the 1144. The stress releif on the 1144 mainly comes into play in that it's stable when you machine it. When removing large amounts of stock from CR steel, it want to move all around (especially mill operations that remove material from one side. 1144 has the residual stresses in the bar stock removed so it doesnt "releive itself" for lack of a better word when machining.

[Conor]

I know chopping and welding axles and then not heat treating is not the most desirable way. But most teams can appreciate the sacrifices endured while making a car on a shoe string budget and I'm aware that some teams have done exactly what we plan to do with great success. Anybody from said scenario want to chime in with material choices or welding methods?

[Jersey Tom]

What if you essentially spaced out the CV hookup inboard from the uprights so you dont have to lengthen your shafts?

[Conor]

The CV is one complete assembly that cannot be torn down. The spline for the hub, the CV housing, the CV, and the inner axle are all connected and cannot come apart without ruining the assembly. I really really don't want to chop and weld without heat treating, but I have absolutely no other choice.

[Jersey Tom]

I guess I've never quite understood how a CV joint works, as compared to a tripod joint, or if there's any difference.. but a tripod joint can come apart super easy. If there was a way you could save the spline for the hub and spline to the differential and whip up some tripod housings for em and roll with that..

[Bill Kunst]

I am pretty sure that you can pull apart a cv joint. The end of the spline that goes into the cv has a snap ring retaining it. The only problem with this is sometimes the snap ring does not comply and you end up cracking the end of the shaft when you pull it apart.

Think about it, how do they get them together, apart, rebuild them, and reassemble them? Carquest and other auto suppliers sell rebuilds all the time.

[Conor]

Bill,

The CV is not off a vehicle, it's off of an ATV. We spent quite some time examining the part looking for any possible way to take it out, but, if there is away, we can't figure it out. It being a Honda shaft, it really shouldn't be a surprise. Japanese manufacturers are quite talented at streamlining assemblies and everyone knows that less parts means less assembly labor and less overall cost of the entire part. If it had a snapring, we would have found it.

[Rex]

We used Honda ATV CVs for several years back in the day. The outboards were off a Foreman Fourtrax or some such. Required equipment for removing stock driveshaft from CV included a strong vice, a block of scrap metal with a hole in it, and a large hammer. Place driveshaft through hole in scrap block, put driveshaft in vice, and hit block into CV along the driveshaft axis until the snapring behind the CV knuckle breaks and driveshaft separates from CV. There was only 1 time this method didn't work, and a local CV shop cut the knuckle race, removed driveshaft, and rebuilt the internals using a rebuild kit for a total of about $100 as I recall.

Not sure which ATV you're using, but if it's the same as most Honda stuff it is a snapring setup like Bill was saying. Even ATV CVs have rebuild kits with new races and balls. You should definately take one to a local CV shop first before resorting to welding driveshafts (unless you just want to make welded driveshafts).

[Conor]

Rex,

I'll give it another look, but that thing just doesn't look like it wants to come apart. The local ATV dealers are no help and only want to sell stuff (go figure). Do you have any pictures of anything that might help us out?

[Rex]

Don't go to an ATV dealer as they do tend to be less than helpful. Go to an actual CV shop. Any decent size city will have one. Usually it's some sketchy-looking building in a less than ideal part of town, but they specialize in CVs and have always been very helpful in my experience.

I'll see if I have any pics this weekend. Basically it's just like the inboard side except that the knuckle part doesn't slide out of the outboard CV cup like it does on the inboard. So there's probably a groove cut through the splines on the end of the driveshaft where the snap ring lives, and it's captured behind the splined knuckle part of the CV internals.

[Conor]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Rex:
Don't go to an ATV dealer as they do tend to be less than helpful. Go to an actual CV shop. Any decent size city will have one. Usually it's some sketchy-looking building in a less than ideal part of town, but they specialize in CVs and have always been very helpful in my experience.

I'll see if I have any pics this weekend. Basically it's just like the inboard side except that the knuckle part doesn't slide out of the outboard CV cup like it does on the inboard. So there's probably a groove cut through the splines on the end of the driveshaft where the snap ring lives, and it's captured behind the splined knuckle part of the CV internals. </div></BLOCKQUOTE>

That would definetely make sense from looking at it. If you have pictures of it apart, that would be the most helpful. Thanks for the help.

[Rex]

I looked and cannot find any useful pictures. I have some of a CV failure, but none of the internals.

[Conor]

Rex,

We called up an Advanced Auto Parts and asked if they had a CV pulling tool. They didn't, but they did have a slide hammer, so we decided to rig something together and see if it would work. To my surprise, the slide hammer they gave us was in an "axle pulling kit" and had everything to take the CV apart. A lot easier than we thought...

[Rex]

Good deal. Now you don't have to weld driveshafts after all!

Good luck!
Rex

[Conor]

It's quite the relief indeed. Man, that sure was going to be sketchy...