Material

[Greg_J]

Hello,

I am trying to find a comprehensive way to determine speeds and feeds based on material. I find discrepancies between many sources, and rightly so there are many factors that determine speeds and feeds.

 

We deal with about 12 different materials and I would like to find the "general" SFPM and FPR. Would the harness of the material be the more accurate way to determine that?

 

Here's an example I look on the box of inserts and it gives me a SFPM and FPR for stainless, but what type of stainless. The feeds they give might work well on 304 but not on 316.

 

How do you go about using the most efficient speeds and feeds?

 

Thanks,

Greg

[Ron Branch @ Verisurf]

quote:

---

Would the harness of the material be the more accurate way to determine that?

---

Yes we have one material here we deal a lot with that has 6 different heat treats depending on the part we are making. I always use the hardness as my rule for sfm and feed rate. I however always go by chip load per tooth never a IMP as my base. Huh, well what I mean is my feed rate per in is done by my chip load per tooth, not just so feed rate that sound good.

 

HTH

[Greg_J]

I go by feed per tooth.

 

I find that the depth of cut and pecentage of tool engagement has big factor on feed.

 

4140 is one of the ones that has many different hardesses for us. Initially when some one says 4140 I think no big deal to machine, but we have one material called 4140 HTSR 28-32 HRC(HTSR=heat treated stress relieved) and it's very hard to machine. It's also called 4140 L80 18-22 HRC I guess that's a oilfield name.

 

I have some Titanium G5(6AL 4V) and Hasteloy C276

in the next few weeks to machine.

 

Material we machine.

Titanium G5

Hastelloy C276

4140 HTSR

4140 L80

4140 annealed

17-4 DH 1150

6061 T6

7075 T6

316 ss

Maganees bronze

Bearing Bronze

Brass

Inclloy 925

Inconel 718

[Greg_J]

So would it be wise to figure out all the SFPM for these materials and add them to the material libary that MC has, then I can grab a tool and click calculate speeds and feeds button?

[Bruce Caulley]

Personally I never use MC's SF calulation. I work out what works best fo a tool and save to a separate library.

 

Bruce

[Greg_J]

You'll set up a tool library for each material?

or

Do you just keep a chart with the SFPM for each material and change the speeds and feeds on the tool for that material?

 

I've been doing the latter, I've been too busy to spend the time on it as well as dealing with post issues and machine def's. Now that things are slowing down abit I can get that all done.

[fro_matt]

4140 HTSR 28-32 HRC sounds an awful lot like 4140 PHT (pre-heat treat, that is also 28-32 HRC) If so I run PHT 400-500 SFM W/coolant for inserted cutters. ( I know coolant) We have handy little slide charts from mitsubishi that i use for SFM, they also do FPT, IPM, MMR and some other stuff i don't use, if you can't figure FPT and IMP by hand...

 

JM2C

[Dave.L]

If you want the best results, always, always, get the S & F from the manufacture of the tool you are cutting with based on the perameters for the particular material. Also, if you have performance problems, the manufacture will help and if their good, will stand behind what they tell you.

 

It's way too hard to have general parameters unless it's just aluminum and even then you can have issues.

 

For this reason, I wish MC had a material table under each tool with parameters that one could enter for that tool. So, when it's 1/2" ABC endmill cutting 4140, the speed & feed are what the table states or when cutting 1018 it's different. (All user defined)

 

To specify paramters from the tool or from the material will never work well, it needs to be from both. Because of this, we adjust the S & F each job based on the material. It's a pain, but it works well for the best cutting results.

 

-Dave

[Bruce Caulley]

quote:

---

You'll set up a tool library for each material?

or

Do you just keep a chart with the SFPM for each material and change the speeds and feeds on the tool for that material?

---

A little of both. As an example I have a "general steel" library that has cutting parameters for each tool that are at the bottom of the manufacturers recomendations for carbon steels as default. I then alter to suit condition and actual material. This way if I forget to check my speeds and feed the worst that happens is a longer cycle time, not a smash. I have other libraries for Ally and plastic, etc, etc.

 

Bruce

[Tim Pruett]

I've been studying this as well, and if I'm understanding everyone here and from the search I did on the forum, the general consensus is to set up tool libraries for each material and plug in the correct sfm and chip per tooth that each tool manufacturer tells you for that material. It seems like this would take a while. Is this the best way to come up with a good starting point for each material/cutter combination? Sorry I didn't mean to hijack a thread but I didn't see any point in starting another one with the same subject.

[Greg_J]

There's no hyjack.

 

I can learn from what ever questions you might have as well. I did search the forum and I didn't see to much on this topic specifically.

 

One of the problem is we have sooooo many tooiling suppliers too get the info from them will take a long time.