Roughing Steel

[Alex Westling]

I have a job coming soon where I will have to do alot of slotting in .5" thick 4340 annealed plate. I dont have alot of experiance in cutting steel so I am looking for some advise picking the best end mill to purchase for the job. I have to cut 50 2"x3" parts out of a .5" plate. I will slot around the profile of the part .25" and then flip the part and slot the other .25". I will most likel use a 3/8" or 1/2" EM.

My mill is Fadal TRM 5hp, 4000rpm max spindle speed, no coolant just an air blast.

I looked around a bit and found some good reviews on variable flute endmills from SGS and Hanita. How would these compare to a solid carbide rougher in terms of depth of cut and speed? I have not used either style so I have nothing to compare them to. I am not conserned with the finish since I will make a finish pass with a different tool. I am more curious which tool will remove material faster a variable flute EM or a Roughing EM. Any help would be appreciated.

[chrisryn]

Personally I would look at a multi master tool from iscar. Since its an insert it will be cheaper than a solid carbide and with the iscar tools I use I scream through steel and cast iron.

[dertsap]

hanita verimill would be my top choice of endmill
as far as comparison to regular endmills there is no comparison , hanita blows them all away

[Alex Westling]

Originally Posted by dertsap hanita verimill would be my top choice of endmill as far as comparison to regular endmills there is no comparison , hanita blows them all away

Thanks. I have heard lots of good things about Hanita Verimills. But will they actually remove more metal than a carbide rougher in a given amount of time?

[dertsap]

yes
like i said look at their website and you should be able to get all the facts in reguard to depths of cut , speeds and feeds ,
they are a tough and fast tool

[little bubba]

Alex, I would go with the variflute. You can probably move about the same amount of material(haven't used a carbide rougher in a long time), but you can just finish the part with the variflute, without having to change a tool.

A 3/8 is plenty beefy for what you are doing, if you get after it, you will be able to stall out your 5hp spindle.

Derstap may like the Hanita's, but they aren't my favorite by a long shot. Several reasons, they aren't cheap. Second, I had J&L send me some 1/2" varimills to put up against the variable flutes/helix that I was using, even with the discount, the varimills were $53, and I was paying $38 for the no names. 70 parts with the nonames in annealed 4140, 450sfm, .020 per rev, about .375 depth, .375 stepover. 70 parts on the noname, started getting dull, put in the Hanita, 3 parts and snap, put in a second Hanita, 1/2 part and snap. Put back in a noname, finished out the last 60 parts. Hanita told me I was running it too hard and too fast.

I've run them a few other times just to see, what I think is, first, the Hanita is not very beefy in the center. When you snap one and look at the cross section, they take out a lot of the carbide, leaving not a whole heck of a lot of backbone in the center. The other thing I don't like is the chamfered corners, they seem to start breaking down on the 135 degree corners. A radius seems to hold up a lot better.

Check out some of the smaller carbide grinders, I think you will get more bang for the buck(the Hanitas aren't bad, I just think there is better value out there). Lakeshore carbide makes some really nice endmills, and you can buy just one without taking it in the shorts. He also recently introduced a variable flute carbide rougher, which I am very curious about. <---- that might be your ticket.

[DareBee]

Not quite a direct answer to your question BUT - I would have the parts plasma cut out of the plate (couple bucks each) and just do the finish machining. This will cost you half the money for the run (time + tooling).

[5axisguy]

Just a little tidbit of info about verimills. The Emuge version will outrun the Hanita by a long shot. They are expensive, I just ran a 3/8 dia. and paid about 75$ for it. But it's worth every penny, what's nice about the emuges' is you can also get different rake angles for different hardness and types of material. I used a negative rake on my test and it just smoked the hanita.