Buying a set of end mills? Which ones?

[Lumencraft (Matt)]

Hi everyone,


I am looking to buy a set of end mills, but I am not sure exactly what I need.

All I really want to do is bore a hole with a flat bottom. I will be using these for Delrin plastic, and aluminum.

I want to get a set that has a wide range of size like 1/8" to 1" or so.

What dont understand is what all the different types are for. Does it matter if I get a 2 flute or a 4 flute? I have seen several words in the description of the items that I dont know what the use is. I am guessing square is what I need to do the job I want?

Also if I could find a set that will bore large diameter holes that have a 3/8 or 1/2" shank would be nice, since I dont have any thing capable of chucking a 1" bit at the moment.

Any help is great, thanks.

 

[Th232]

Can't help you too much, but I believe what you're looking for are some centre cutting end mills. Two types, centre cutting and non-centre cutting, the latter can only go sideways and not down. I believe that they're most commonly 2 flute, 3 and 4 flute centre cutting mills are possible, but a fair bit rarer.

Since you just want a flat bottomed hole, those would be regular end mills. Pretty sure that if they're ball nosed or bull nosed cutters then it'll be explicitly stated in the description somewhere.

 

[PEU]

Don't buy a set, long time ago I purchased a set exactly like this one http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=170461459724 (from other seller)

To put it in mild words... its a piece of cr@p

Purchase the endmills you need in solid carbide and enjoy the tool for a long time.

The number of flutes determine the finish on the piece, but also not all materials are happy with more than 2 flutes, aluminium is one example because if the clearance between flutes is not large enough chips tend to stick to the endmill thus not allowing it to properly cut.

For plastics a 2FL endmill will do the job.


Pablo

 

[wquiles]

... Purchase the endmills you need ...

That is what I do as well. Better to spend on a quality endmill in the few sizes you will use most often, than getting a crappy "set".

 

[KC2IXE]

I'll Nth - don't buy a set, buy what you need

BTW, end mills will NOT make a truely flat bottomed hole - they are slightly higher in the middle, as an endmil is SLIGHTLY "fishtail" shaped - It's NOT much, and for most purposes can be considered flat, BUT...

 

[Lumencraft (Matt)]

Ok so it sounds like so far the consensus is for get the sets. Get a few quality mills in specific sizes.

I'll Nth - don't buy a set, buy what you need

BTW, end mills will NOT make a truly flat bottomed hole - they are slightly higher in the middle, as an endmil is SLIGHTLY "fishtail" shaped - It's NOT much, and for most purposes can be considered flat, BUT...

For the plastics this will be a non issue. I guess for the aluminum I will just have to see. One of the primary reasons for me getting an end mill is I want to bore out a larger flat surface for a P7 emitter. I was unable to get a surface flat enough using a jig with a burr on the end.