How to choose a high quality end mill cutter?

[Tim StevensParticipant @timstevens64731]

hello SoD

As an ex-quality engineer, and a quality conformance engineer, I am sure I remember what quality means to an engineer. It means 'Compliance with the specification'.

Of course, the term is used without any reference to a spec, and therefore is a very useful term for marketing. Whether marketing ever uses terms which are useful to anyone else is not borne out by my experience.

Cheers, Tim

[SillyOldDufferModerator @sillyoldduffer]

Posted by David Hogg on 29/03/2022 22:20:03:

…

Not 'pussy footing' or taking cuts that are too light needs some getting used to! In all other forms of craftsmanship I've experienced it's always been that you can never be too gentle with tools / machines … but here it seems it's actually detrimental to the tool to be too gentle!

I certainly hear what you're saying about internet videos, and there's definitely a huge variety out there, from great to really poor … although that said, I'm sure you also get a variety in the quality of books depending on who's written them, although the variation probably isn't as pronounced.

I think the Blondihacks tutorial videos I've been following deserve credit, …

Blondihacks is much better than most!

The advantage of technical books is they're usually reviewed repeatedly and rely on written references that have also been reviewed. Technical authors try to get their facts right and keep the work consistent. Books are usually a notch better than magazine articles, and magazine articles are a notch better than web material. The difference is the amount of review put in before publication. Ideally, a talented author with access to a technical library and plenty of practical experience sends the draft to a peer group, and once they're happy, the final draft goes to an wide-awake Editor. A good editor will make many improvements.

Internet videos are often put together by unqualified inexperienced enthusiasts and then put on the web without being reviewed at all. Mistakes are often left in without comment. Worse, unlike books, videos inadvertently expose bad practice, like leaving keys in the chuck, polishing work spinning in the chuck with a rag, loose clothing, wrong tool-settings, dodgy electrics, clearing swarf by hand, gloves and rings, no eye-protection etc etc. Workshop practice books often list "don'ts", unfortunately many internet videos have them in the background as if they were perfectly OK, accidentally creating bad-habits galore…

On the not pussy-footing side, it is counter-intuitive, and on top of that HSS and carbide are a bit different. Although both are blunted by rubbing, when HSS fails to produce a good finish, it makes sense to slow down and back off. Conversely, carbide probably needs to go in harder and faster – the exact opposite. I have a suspicion HSS fans who don't get on with carbide may be applying the wrong technique. (Though not having fast powerful machines doesn't help either.) Boils down to picking up information from whatever source suits you and trying it critically in the workshop. Don't expect buying 'quality' tools to de-skill anything – learning how to get the best out of what you have is vital. Practice and adapt.

Dave

[Nigel Graham 2Participant @nigelgraham2]

"Quality" cutters?

As others have explained, the adjective alone is not really sound technically. At worst it is no more valid than that semi-illiterate advertising slogan, "It just got better" . (Was it BT's?).

Yes there are tools and materials available that would give you nowt but trouble; and these days cost is not always a good guide to intrinsic quality by specifications.

So unless you are engaged in some very high-performance engineering in which case you'd not be asking as you would be able to quote to us material, work-piece and tool Specifications to the nth degree anyway, do what most of the rest of us do:

– select the appropriate cutters for material and purpose,

– buy them from the established suppliers such as those who advertise on this Forum and in the two magazines (retailers generally purchasing from professional-engineering wholesalers, not dubious sources in the nominatively riverine or coastal markets),

– and think about how you use them!

Over-think not!

[Mick B1Participant @mickb1]

^ Top-quality advice throughout, Nigel !

Edited By Mick B1 on 30/03/2022 14:23:16

[JasonBModerator @jasonb]

Though the problem with that is most of the suppliers that have these adverts all do a basic range to suit those with deep pockets and short arms so you will be getting cutters that may not be that good, and none of them get their cutters from Professional engineering wholesalers.

The likes of W***o, A*c, C*****s, A*******r and R*g to name the main players all import direct and have budget cutters particularly ones in sets and often with a very strongly coloured TIN coating. Just take a look at sat the TiN coating on a Dormer and compare that with the "TIN" coating on these budget cutters and its no wonder one cuts better than the other

As the OP wants as step up from this "quality for the price" then it is better to look at suppliers that supply the smaller industrial, commercial and educational markets such as APT and Cutwel as well as the premium range from ARC. It is then upto the OP to decide if he wants their run of the mill own brand range which I feel will do the job or to go for the higher performace name brand and spec cutters which are unlikely to give much of a difference in cut and certainly not proportional to the price increase on hobby machines.

[Tim StevensParticipant @timstevens64731]

I am loth to query a statement by a moderator, but here goes:

Jason – I wonder if it would help reduce confusion if the coating used on lots of cutters were referred to as TiN, rather than TIN? Tin is a soft metal, used for coating copper pans in the kitchen, and no use at all in resisting the pressure and friction of machining.. Titanium Nitride is a much tougher material. Using the term in this way also encorages people to realise how chemical formulae work.

Regards, Tim

[JasonBModerator @jasonb]

Tim that is why I said TiN for the Dormers and "TIN" for the not brilliant cutters as who knows what it's makeup really is. I'll take a photo tomorrow and show how different the two coatings look.

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