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Hukshawn
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That I know.
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4GSR
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As I said above, it's a alloy steel. Fits between medium carbon steel and tool steel.
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4GSR
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300 to 600 SFM is a good range using a coated insert with C-6 - C-7 base grade for soft (annealed) alloy steel.
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4140 has several hardness availabilities. Fully annealed, about 10 to 12 RC, Half hard, about 25 RC, and fully hardened and ground, 52 -55 RC. The half hardened is really great to work with if you accept that it's hard. High speed will cut it with little trouble, run about 2/3 of 90 FPM. I can't give a surface feed for carbide, but 200 to 300 doesn't sound bad. There's another version, the mfgr calls it ETD 150, its a drawn cylindrical steel, twice the yield strength of CRS, 150,000 psi. Its workable with HSS, too.
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The pre-hardened (or work hardened) material is where I see most of the sparks, in my limited experience, with higher carbon steels. With steels like 4140, you must maintain a depth of cut and feed rate that lets the tool get under and stay under the material as it hardens. That means that the tool will be traversing the material fairly quickly in relation to the diameter. Nothing to be afraid of, just keep your focus on the cut and the cut only while cutting in tighter places.
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It amazes me the different ranges of hardnesses 41xx material comes in.
I only work with two hardness ranges that relate to yield strength. This is how my industry operates in.
10-22 HRC that carries 80-105K yield, also in the same hardness range 65-105K yield, just depending what the design criteria wants. Generally Q & T, but have used annealed as long as it had a stress relieving cycle prior to physicals performed.
last 26-36 HRC that carries a 110-140K yield range. This is a Q & T grade. There are a couple more yield ranges I design with that get little more detailed with certain alloy steels like 4330 and 4340, I won't even bring up here.
I agree with fully annealed being 10 - 12 HRC, probably more of a range of 4 to 14 HRC. Never heard of half hard in steels, but a mid range hardness, depending on the steel vendor preference, 24-32 HRC, which with most is their Q & T HT grade. Full hard and ground, never heard of. And this varies depending where you live. Oh, ETD150 is solid bar, made by the old Bessemer process. Has a 125K miminum yield and 150K tensile. I used to cut a lot of it over the years, good old tough steel that cut relative good, even with HSS.
I only work with two hardness ranges that relate to yield strength. This is how my industry operates in.
10-22 HRC that carries 80-105K yield, also in the same hardness range 65-105K yield, just depending what the design criteria wants. Generally Q & T, but have used annealed as long as it had a stress relieving cycle prior to physicals performed.
last 26-36 HRC that carries a 110-140K yield range. This is a Q & T grade. There are a couple more yield ranges I design with that get little more detailed with certain alloy steels like 4330 and 4340, I won't even bring up here.
I agree with fully annealed being 10 - 12 HRC, probably more of a range of 4 to 14 HRC. Never heard of half hard in steels, but a mid range hardness, depending on the steel vendor preference, 24-32 HRC, which with most is their Q & T HT grade. Full hard and ground, never heard of. And this varies depending where you live. Oh, ETD150 is solid bar, made by the old Bessemer process. Has a 125K miminum yield and 150K tensile. I used to cut a lot of it over the years, good old tough steel that cut relative good, even with HSS.
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The manufacturer of the inserts will likely have printed a guide to speeds and feeds on the package, start there and work up or down as required, I have never seen a multi insert facemill running at recommended speeds that did not spark a good deal in steels when used dry as intended.
The heat goes with the chips so they should be a nice skin burning shade of deep blue, do this in an enclosed machine when possible.
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Hukshawn
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Lol. So much of this has been straight up chinese for me. I don't understand anything to do with yeilds and hardness, etc.
I'm gonna try 400 sfm tonight, like mentioned, and see how it goes.
I'm gonna try 400 sfm tonight, like mentioned, and see how it goes.
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Hukshawn
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I did one jaw. Way thicker than I planned. But, I bought the most reasonable sized stock I could find on the shelf without spending more and having them cut something. And I hogged off as much meat as I was willing. So, ya. The jaws will be 1" thick. Which is fine I suppose. Doesn't make much difference. But, it's square within .0015" over 6" which seems to be the best I can get with the equipment and tooling I have. I have two vises on the table right now cause I'm a smart ass and think I really need two vises... Well, it turns out that trying to run near the edges of the tables available length is causing me problems. The wollow in the in the dove tails is showing up as run out. I think for the second jaw I'm going to move one vise back into the center and try the second jaw. See if I can get more accurate.
So, it's running much slower than what seems comfortable. I'm at 600 rpm. No more sparks, it runs smooth enough, but the flaws in this face mill are rearing their ugly mugs... There's one tooth that's lower than the rest by a thou or whatever. You can see it in the finish and I can hear it when it cuts. I've played with different inserts but it doesn't make a difference. I tried remedying it by just grinding that insert down a touch. Helped. But, I'm finding these chinese eBay inserts to be junk. I'm running through them like underwear. I've gone through 4 already and one side of these next 4 are already dull/chipped.
I could go to my local tool shop and order better ones, but I'm not sure it's worth it with this face mill.
Can you even correct that one tooth being lower? Would I always just have to compensate by grinding that insert? Face mills are expensive! But I hate when things don't work how I want them too! Bah.
So, it's running much slower than what seems comfortable. I'm at 600 rpm. No more sparks, it runs smooth enough, but the flaws in this face mill are rearing their ugly mugs... There's one tooth that's lower than the rest by a thou or whatever. You can see it in the finish and I can hear it when it cuts. I've played with different inserts but it doesn't make a difference. I tried remedying it by just grinding that insert down a touch. Helped. But, I'm finding these chinese eBay inserts to be junk. I'm running through them like underwear. I've gone through 4 already and one side of these next 4 are already dull/chipped.
I could go to my local tool shop and order better ones, but I'm not sure it's worth it with this face mill.
Can you even correct that one tooth being lower? Would I always just have to compensate by grinding that insert? Face mills are expensive! But I hate when things don't work how I want them too! Bah.