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Joined: Fri Jan 20, 2017 4:42 am
Posts: 21

Post Posted: Wed Jul 26, 2017 3:56 pm 
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Hi everyone,

Mill finally arrived at the shop after a long delay due to house remodel work and am cruising through the MSC catalog looking at mill bits and cutters. Is there a general consensus on brands to go with and ones to avoid? I see the prices vary wildly even within HSS and Cobalt cutters so I'm looking for some education from the masses here.

Thanks!

/r

Josh

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Joined: Fri Nov 30, 2012 9:40 pm
Posts: 224

Post Posted: Fri Jul 28, 2017 12:42 am 
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I like the Cobalt cutters for finish cuts. Cobalt is not nearly as tough as carbide but will give you a smoother finish cut. These normally run at a lower speed than carbide. I know very little about the newer carbides, micro-grain. They are suppose to have a longer life/use and have a sharper cutting edge. Most of these were developed for high speed CNC's machines. I buy very little HSS end mills unless it's 2/3 flute for machining Al.

Sorry I can't add any more. But I'm just getting back into after being away from it for 20 yrs.

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David

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Joined: Wed Mar 16, 2011 4:45 am
Posts: 284

Post Posted: Fri Aug 04, 2017 11:20 am 
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Carbide is hard and more rigid, but the edges chips easily or the cutter will break if the set up isn't rigid. It's somewhat like glass, very hard but brittle. Of course to be successful at making nice cuts you need the part held sufficiently and the machine to be rigid enough, but going through the learning curve can be more expensive if you are damaging much carbide. Steel cutters are more resistant to breaking and edge chipping, but the edges will wear faster. HSS cutters need to run at a lower surface speed, if they are run too fast the edge will go away in an instant. If they are run with a conservative surface speed they will cut most steel well enough if it's not too hard and give a decent service life.

Generally with CNC mills and perhaps high end manual mills that have good ball screws carbide tooling is more economical in the long run. If there is backlash in the lead screws you need to feed the work piece into the cutter edge rather than climb mill, or you run a high risk of chipping or breaking a carbide cutter and it's not good for steel tools either but the don't break as easily. The reason is climb milling will pull the work into the cutter and any slack in the lead screw will pose the risk of suddenly overloading the cutter which can break it and give a poor finish, so "conventional milling" is usually best for manual mills. Even if you use conventional milling a carbide tool can chip easily if the speed and feeds are off or if the part is not rigid, any chatter is very hard on carbide.

So what kind of tool material is best will depend heavily on the machine it used on and the type of material being cut, as well as the skill of the operator.

MSC's house brand is AccuPro and would probably be a good value for you. Higher priced end mills like some from Niagara and OSG are usually more consistent in the grinding and may perform better in higher rpm CNC machines but for a manual mill the differences probably aren't worth it. Probably more important than a particular brand is to buy cutting tools that are best suited for the material you are cutting. In general end mills that have 2 or 3 flutes and a higher helix usually work better for aluminum and end mills with 4 flutes or more and a straighter helix work best in steel. Often there are more differences than just the number of flutes and helix, the grind angles on the cutting edge are tailored to different materials.

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Joined: Sat Feb 26, 2011 2:48 am
Posts: 619
Location: Northern Virginia

Post Posted: Fri Aug 04, 2017 11:54 am 
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Good to see you post Mike, Welcome back. And good advice to boot!
Joe

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Joined: Sat Jul 28, 2012 11:48 pm
Posts: 156

Post Posted: Sat Aug 05, 2017 2:41 am 
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I sublease a machine shop and the owner has been in business for 35 years. He turned me onto IMCO carbide end mills because the have super long life. I purchased mine through a Machinist supply store. When I went over to purchase the IMCOs, the store clerk exclaimed that these were the most popular brand they had because of their longevity. And the pricing was very competitive against other top manufacturers. It's been over 2 years since I purchased them and I have yet to get them resharpened after cutting quite a bit of 303, 4140, and 1018. My next fixture I'm making is made from 1018 and will allow me to trim the radius back on a Stan Chen 2 magwell/MSH in order to blend it into the frame and checker the MSH. It will attach to my rotary table. I hope my 3/8" IMCO makes it through and I didn't jinx myself! :-) I'll post pics once I'm done...

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Joined: Tue Jun 24, 2014 4:13 pm
Posts: 243

Post Posted: Sun Aug 06, 2017 7:59 pm 
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Please do! I'd like to see a MSH fixture. I've been drawing some stuff up minimal success. I tend to over complicate things though

Sent from my SM-N910V using Tapatalk

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Joined: Fri Jan 20, 2017 4:42 am
Posts: 21

Post Posted: Mon Aug 07, 2017 4:44 pm 
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Thank you everyone for the input! I had a change in finances occur with my work (active duty back to reserve) so I had to scale back the machinery I wanted to go with. I'm rolling with a Grizzly G0759 which I know isn't the most rigid machine but good reviews for what it's worth. Filling the base with concrete to build up some bottom weight but the bit selection I was told was going to play more of a part with everything due to said machine rigidity.

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