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davidwdyer
01-05-2010, 01:23 PM
As you can see from other threads, I am playing with the idea of making some gear cutters. I have bought, evidently, some D6 tool steel.

But I also got some 1045 to make some gears. I got that because it was the only stock they had in the size I wanted.

How can I do case hardening?

Do I have to buy some special chemical?

Would such a steel be sufficient for cutting gears also?

Upon resharpening, would I have to harden again?

Sorry for all the questions, but I still have a lot to learn, and it seems this forum is full of folks who know such things and have worked with them for years.

Peter N
01-05-2010, 01:48 PM
David you can flame harden 1045/EN8 without having to use case hardening.
Heat it up till it looks bright orange or like cooked carrots, hold it there for a while (depending on thickness) then quench it in oil or water.

I suspect it will only go to around mid/high 40s rockwell C though, which is enough to prevent wear and galling but not really hard enough for any extended use as a cutter, or for cutting hard/tough materials.

Brief heat treat linky here: http://www.westyorkssteel.com/en8.html

Peter

Oldbrock
01-05-2010, 01:50 PM
1045 has enough carbon in it that you don't need to case harden it, just heat to dull red - non magnetic - and water quench. Then draw to light straw. However not quite good enough for making cutters unless it's a one off application. If you can't find tool steel 4340 will make an acceptable cutter. only you need to oil quench it. You have to go more slowly that HSS cutting speeds for cutting your gears and the edge won't last as long. No need to reharden after regrinding. If the steel is 10xx it is usually water quenched and if the first number is 2 or more then it is alloy steel and should be oil quenched. My rule of thumb anyway, others may disagree, Hope this helps, Peter

.RC.
01-05-2010, 03:22 PM
If the steel is 10xx it is usually water quenched and if the first number is 2 or more then it is alloy steel and should be oil quenched. My rule of thumb anyway, others may disagree, Hope this helps, Peter

That is correct, Steels starting with 10 are just plain carbon steels..

Steels starting with other numbers are stels containing alloying elements..

For example, 11XX and 12XX are free cutting steels. 41XX is a chrome molybdenum steel.

pcarpenter
01-05-2010, 03:42 PM
I read the OP's post a bit differently...that he had some D6 for making cutters and some 1045 for making gear blanks (raw material for the gears).

As for the request to case harden, I know that commercially some gears are nitrided (using other steels that nitride well) because it produces a hard case. The premise here is that the inner portions of the gear are not that hard so that they deal with shock loads better....the same principle used in hardening hammer heads etc. As such, through hardening may be less desirable.

Paul

Peter N
01-05-2010, 04:07 PM
If the steel is 10xx it is usually water quenched and if the first number is 2 or more then it is alloy steel and should be oil quenched. My rule of thumb anyway, others may disagree, Hope this helps, Peter

Not quite correct Peter.
Water gives a faster quench and rate of heat transfer than Oil and can provide a corresponding increase in the hardness. Brine quenches even faster.
Whilst the heat transfer rate of Oil is slower it can prevent cracking and distortion which can occur with rapid quenching. For complex parts or parts with stress raisers like internal sharp corners, then an Oil quench will reduce the chance of cracking or distortion.

Some of the alloying elements in high strength low-alloy steels like EN24/4340 have the effect of reducing the rate at which it NEEDS to be cooled to retain the change in grain structure, and hence these can be quenched in oil or even air cooled at a much slower rate. The advantage in this is again the reduced likelihood of distortion and cracking from stress induced by the sudden change.
So the quenching medium as often depends on the geometry and nature of the part as much as it might do on the chemical composition, and is worth bearing in mind. I often quench parts made from gauge plate (01) in water if the shape is simple and I want a harder part.

Hope that didn't sound too much like a lecture, but the point was worth making.

Peter

Peter N
01-05-2010, 04:08 PM
I read the OP's post a bit differently...that he had some D6 for making cutters and some 1045 for making gear blanks (raw material for the gears).

Paul

Well spotted Paul. I for one totally missed that bit...doh

DR
01-05-2010, 04:25 PM
Why bother making your own cutters? The shape is fairly complex for an involute gear, not the easiest thing to make.

I've seen third world gear cutters at very reasonable prices. Obviously, they aren't the best, but will certainly be better than a home-made one.

davidwdyer
01-05-2010, 04:26 PM
Everybody is right!!!

I bought some tool steel to make cutters and some 1045 to make gears.

But really I want come larger diameter stock for an eventual try at making some involute cutters following Ivan Law's book.

Here in Brazil, this stuff is absurdly expensive.

McMaster has a chunk I can get while in the U.S. and bring down.

BUT, it weights a ton. Well, not quite a ton but a 3" dia. by 1' piece must weight quite a bit, so I was thinking if there was something I can find here which would substitute. I'm imagining this in my carry on bag and going through airport security with it, ha ha. Maybe I should try carrying it in my underwear.:rolleyes:

So my ideas are mutating as time goes on.

Thanks again for any and all help.

Carld
01-05-2010, 04:40 PM
Can you buy it here and ship it UPS to your home or shop in Brazil?

Can I get it for you and ship it to you by UPS?

davidwdyer
01-05-2010, 05:00 PM
Can you buy it here and ship it UPS to your home or shop in Brazil?

Can I get it for you and ship it to you by UPS?

Thanks for offering. I really appreciate it. BUT, if done in that way, the customs duty is about 60% plus shipping. I will be in AZ soon and think I can find a way of fitting it in luggage. With the right airline, there still is a 70# limit per bag to Brazil.

CountZero
01-05-2010, 05:01 PM
But one question remains to be answered, can 1045 be casehardened? Either with box carburising or some case hardening compound. Guess I will have to find out myself some day..

Here 'proper' tool steels are readily available, but not usually too economically if buying small quantities. Steel similar to 1045 is plentiful OTOH... and for a special cutter for a few times use case hardening would be sufficient I think(sometimes perhaps even without the case hardening).

Carld
01-05-2010, 05:09 PM
C 0.42 - 0.5
Fe 98.51 - 98.98
Mn 0.6 - 0.9
P Max 0.04
S Max 0.05

That is the properties of 1045. You will notice it is .43% carbon and can be hardened better than just a case hardening. You can case harden it if you want but the rest of it will be hard from the case hardening process.

It you weld it and try to machine it you will find out how hard it can get.

Allan Waterfall
01-05-2010, 05:13 PM
Brief heat treat linky here: http://www.westyorkssteel.com/en8.html

Peter
Thanks for that link,I've bookmarked it.First time I've seen a supplier that can do 2" Silver steel.

Allan

Carld
01-05-2010, 05:17 PM
What if I ship it as a gift? I think I can get it free from someone here.

Oldbrock
01-05-2010, 05:40 PM
You are correct, I didn't want to get into too many details. Peter

Evan
01-05-2010, 05:50 PM
You can case harden 1045 just fine. It will harden the interior and the surface at the same time. The surface will be harder of course. 1045 goes harder than the carbon percentage would seem to indicate because it is a low manganese steel. Low in this case means not high manganese instead of no manganese. Anything up to 1% is considered a low manganese steel.

In the instance of gears there is no reason to case harden at all, normal heating and quenching will do fine. I harden 1045 frequently and it will easily go file hard. For most purposes I draw it back to blue unless I am making a cutter like a gear hob. It's low enough carbon that it doesn't crack even with a brine quench and distortion is minimal if it is quenched right.

To quench it needs to be plunged and simultaneously agitated for least distortion. When making a hob I leave the piece long and chuck it in a hand drill to hold it. To quench I run the drill while I plunge it which ensures that it is evenly quenched.

davidwdyer
01-05-2010, 05:52 PM
What if I ship it as a gift? I think I can get it free from someone here.


Naturally, that is an interesting possibility. We would have to check shipping costs. The piece I am thinking about ordering is $89.34 and would probably weigh about 15 pounds (just a guess).

Gear cutters here are about R$500.00 Reais each, which translates into about $300.00 at today's exchange rate.

No doubt its just an obsession (just like the rest of this tool/metal addiction) but being able to produce my own gear cutters is intriguing me.

Having read and still trying to assimilate Ivan Law's book, it seems that there is a fairly simply way to approximate an involute curve. He uses round hardened buttons to cut. I am imagining that by cutting drill rod at a slight angle, therefore producing a slight oval shape, you could come even closer to this curve. According to him, his method with round buttons is well within typical tolerances.

lazlo
01-05-2010, 06:01 PM
http://i164.photobucket.com/albums/u15/rtgeorge_album/saw2.jpg

lazlo
01-05-2010, 06:03 PM
But one question remains to be answered, can 1045 be casehardened? Either with box carburising or some case hardening compound.

The question has been answered several times already :) Carburizing adds carbon to the surface of low-carbon steel: you heat low carbon steel packed with a compound that liberates carbon. That turns the surface of the low carbon steel into high-carbon steel. Then you heat to hardening temperatures and quench, and get a case-hardened skin with a low-carbon core.

1045 is medium carbon steel, with .45% carbon. It doesn't need additional carbon to harden it. So carburizing is unnecessary for heat treating 1045. If you want to harden the skin, just heat it with a torch as Brockley recommended, and quench with water.

davidwdyer
01-05-2010, 06:04 PM
The question has been answered several times already :) Carburizing is where you heat a low carbon steel packed with a compound that liberates carbon. That turns the surface of the low carbon steel into high-carbon steel. Then you heat to hardening temperatures and quench, and get a case-hardened skin with a low-carbon core.

1045 is medium carbon steel, with .45% carbon. It doesn't need additional carbon to harden it. So carburizing is unnecessary for heat treating 1045. If you want to harden the skin, just heat it with a torch as Brockley recommended, and quench with water.

I'll certainly give that a try. Thanks so much. There is a lot for a beginner to learn in this field.

Evan
01-05-2010, 06:05 PM
Can you buy it here and ship it UPS to your home or shop in Brazil?

Can I get it for you and ship it to you by UPS?

Shipping overseas via courier is breathtakingly expensive. I just ran a quote through UPS shipping from Berkeley to Rio the cheapest way for an 8x8x4" 10 lb package. Prepaid and dropped off at the retail counter, no pickup, no insurance, $100 declared value.



UPS Worldwide Expedited SM
shipped 5:00 P.M. Tuesday January 5, 2010
Delivered By End of Day Monday January 11, 2010 - Guaranteed

279.91 USD*

*fuel surcharge included

davidwdyer
01-05-2010, 06:08 PM
WHOAAAH!!!! That's expensive.

I think it will be better to try smuggling it in my underwear.:D

Its got to be possible if I keep the other heavy iron tooling content of the luggage down (a hard job) to get it in some bag or other.

Evan
01-05-2010, 06:21 PM
If they search your baggage and find it whatever you do don't tell them you are making gears with it. They won't believe you. Say it's a part so your machinist can repair the engine on your boat. Also, don't even think of mentioning cutters. :eek:

CCWKen
01-05-2010, 08:46 PM
A chunk that size is going to weigh nearly 24 pounds (23.9). USPS Flat Rate to Brazil would be about $56 but it's 4 pounds over the maximum. Best try to ship it in your luggage and hope it hasn't absorbed any radiation. :)

Forgot to mention: Plain old Priority Mail International for 24 pounds would run $105.75.

lazlo
01-05-2010, 09:07 PM
I want come larger diameter stock for an eventual try at making some involute cutters following Ivan Law's book.

McMaster has a chunk I can get while in the U.S. and bring down.

BUT, it weights a ton. Well, not quite a ton but a 3" dia. by 1' piece must weight quite a bit

FYI: commercial involute cutters are quite a bit smaller than that. I just measured some 1" bore involute cutters in my drawer, and they're 1.7 - 2.4" diameter, depending on the DP. The 7/8" bore cutters are even smaller.

But since you only need thin slices, you might consider Ken's suggestion of a flat-rate box: just slice them into manageable 20 lbs chunks.

davidwdyer
01-06-2010, 05:21 AM
FYI: commercial involute cutters are quite a bit smaller than that. I just measured some 1" bore involute cutters in my drawer, and they're 1.7 - 2.4" diameter, depending on the DP. The 7/8" bore cutters are even smaller.

But since you only need thin slices, you might consider Ken's suggestion of a flat-rate box: just slice them into manageable 20 lbs chunks.


Hey, that's a good thought! My arbor is 1" but if I don't need 3" then a piece with 2.5" dia. will be very much lighter and cheaper too. I was just guessing on the dia. since I didn't have anything here to compare it to.

lazlo
01-06-2010, 09:48 AM
David, here are a couple of measurements to get you started:

7/8", 24 DP cutter, 1.75" OD x .180" thick
1", 24 DP cutter, 1.75" OD x .180" thick
1", 16 DP cutter, 2.11" OD x .20" thick
1", 16 DP cutter, 2.45" OD x .20" thic

...and I did find one giant 6 DP cutter: 3" OD x .565 thickness.

I'd bet those cutters are a lot thinner than you were thinking.

davidwdyer
01-06-2010, 09:54 AM
Lazlo,

Thanks again. It looks like 2.5" would be plenty. The giant one I will probably never need. Sounds like it's for a gear size that might not fit well on the mill.

Also, you are right, they are much thinner than I expected. It is going to be a little tricky machining the second side on something that thin. Possibly the mill will work instead of the lather for the second side after sawing. Probably have to make a fixture of some kind.

vpt
01-06-2010, 10:01 AM
How does heat treating compare in harness to cryo treating?

Carld
01-06-2010, 10:39 AM
davidwdyer, you have a PM.

davidwdyer
01-06-2010, 10:49 AM
davidwdyer, you have a PM.


OK. I think I replied.

Carld
01-06-2010, 11:14 AM
Yep, and I replied back that I am glad you found what you want. It's a shame that things are so expensive in Brazil.