Todays daft question

If the usual way of using these is to cut using the flutes(i.e. on the side), why are they called "End Mills"

Ours not to reason why, ours just to cut and die !

To distinguish them from slot drills which will plunge cut. The end can only be used for milling hence end mill

Unless you have ctr cutting end mills

They can be used for facing and edge milling. Most people don't use the flute edges enough. As said, they won't plunge or drill unless they are centre cutting.

They can be used as End Mills, or as small diameter slab mills by cutting on the flutes.

The only thing to take care over is not to exceed a safe depth of cut.

The usual rule of thumb is no more than a quarter of the cutter diameter.

The feed rate should be based on a feed per tooth of about 0.002" (0.050 mm) . The actual feed rate will then be determined by the number of teeth and the rotation speed.

A worn or blunt cutter will need to be treated with more respect and care.

Since the machine will have backlash, it is not advisable to climb mill, for fear of the cutter snatching and pulling itself into the work, to the detriment of both! You might get away with partially locking the travel on that axis, but better to be safe than sorry. Industrial machines will have backlash prevention built in, but not on the machines that we can generally afford!

The work should always approach the cutter so that it is head on to the approaching cutter teeth.

Overdo things and you might be in market for a new cutter!

HTH

Howard

Unlike Howard I always use the cutter diameter as DOC and 1/4 diameter as maximum stepover, feedrate to suit material and spindle rpm available.

Emgee

Possibly to distinguish them from side and face or slab cutters as used on horizontal milling machines.

Andrew

I've long since given up expecting engineering terms to be logical or correct within the rules of ordinary English.

'End' is wrong because End Mills usually cut on the side, though they can cut on the corner and base as well.

'Mill' is wrong, because it's not a mill. Nor is a milling machine!

'End mill' is jargon in my book, but I like jargon - it's the most efficient way for experts to communicate! Pass me a 10mm end-mill is much less waffle than 'pass me that 4-flute Titanium Nitride coated High Speed Steel milling machine cutter', which is still not right either. Jargon gets the job done, provided the code has been learned.

Dave

I tend to just call them 2, 3 or 4 flute milling cutters as there are so many variants these days unlike when you just had the choice of screwed shank slot drills or endmills.

Same with the 1/4 dia rule of thumb which is a bit outdated now, look in any manufacturers cutting data charts and Ap (Vertical DOC) will be 1 to 1.5 x D and Ae (horizontal DOC) typically 0.1 to 0.1`5 x D

The photo does not show the end of the cutter to determine whether it is end cutting or not. The way to tell is that an ordinary non end cutting mill has a central plain portion, probably with a centre hole in it. An end cutting mill has one flute extending right to the centreline so that it can plunge, which can be useful for counterbores, or to then move sideways. The end of the hole produced by any end cutting mill or slot drill is slightly conical, shallower in the centre, which does not matter most of the time, but is a factor to be remembered.

Please don't worry too much over what things are called. If you do, you will never be able to cope with brushes made of solid carbon blocks, points which are flat, etc etc.

I suspect they were called end mills, originally, to distinguish them from milling cutters which look like circular saws but thicker.

Cheers, Tim

Agree and because they have cutting edges on the end. They probably developed from spot face cutters which are intended to cut only on the end but someone thought that with a little extra filing they could make it cut a bit sideways to increase the area of the spot face.