Do HSS End Mills still serve a viable purpose for the home machinist?

[ltlvt]

Mine does not move at all in the lowest position. There's a certain amount of inertia that must be overcome, so the size of the table, tightness of the gibs, the stuff sitting on the table, probably all contribute. To go slowly I usually turn the power feed on at it's lowest setting and then dial up until the table starts to move. Once the table is moving I can turn it down a smidge, but if it stops I have to start over. I'm sure that on a smaller table it'd move right away.

GsT

I can relate to the same with my Align on my PM 833-T mill. However I have abused it in the fact that by mistake I plugged it into 220volts and had to replace the board. It works but seems to be really fast. I have a brand new potentiometer for it just have not installed it yet. I keep getting myself into trouble with the power feed on the PM 833-t mill Leaving the table locks locked is my downfall. Just recently I took some red Dykem and painted the lock handles and also labeled and painted the controls of the power feed. I hope the new Potentiometer will help reduce the speed.

 

[dabear3428]

Please identify "Aluminum inserts"

same as normal inserts but sharper (and more fragile) work like HSS on mini lathe.

 

[ChazzC]

Please identify "Aluminum inserts"

Shorthand for “inserts designed for cutting Aluminum,” like these for example:

https://a.co/d/h2Y6Wep

Highly polished, sharp edges and significant rake.

 

[Growley Monster]

I started out using HSS exclusively and then I bought something or another that came with a holder and some triangle carbide inserts. I went a long time without using them because I assumed that my Vevor 7 x 12 wouldn't have the power or rigidity to use them. When I finally decided after sharpening a tool like 3 times cutting a feature on a big piece of SS, I thought I would try the carbide. I was rather pleased by the job it did. I bought a couple sets of holders and boxes of inserts, and started using them a good bit. I like the nice shaping of carbide inserts. Whatever you want to do, there is a profile that will gitter done. If you blow out a point, just loosen the screw and rotate the cutter to the next point. For most of the stuff I do, the cheapies from amazon and fleabay are good enough, and very cheap. I still really like the flexibility of grinding a point on a piece of HSS, though, and tailoring the angles for the particular cut, and I love the surface finish I can get with HSS on aluminum or bronze or brass, or mild steel. But I like the durability of the cutting edge of the carbide, and the fact that they are sharp and ready to go right out of the box. I am still learning about all the different specs for different cutters and I am sure I am sometimes using the "wrong" one, but they always do a decent job if I am patient and I manage the cut properly. So yeah, I use both. I like both. And I can get by with just one or the other, for tthe most part, if I have to.

 

[m1kemex]

Carbide is superior in every way compared to HSS. The problem is, there are many grades of carbide, many ways to use carbide in a tool, and hobby machinists usually can't tell the difference. Stuff you find in places like eBay is exactly the kind you shouldn't get: mostly surplus from production runs that are often focused on wear resistance to keep tolerances in check. That stuff is super fragile and chips just by looking at it. It's meant to be used only in very strict conditions.

Don't ask me how do I know. Let's just say I began hoarding stuff I shouldn't.

In broad terms, the finer the grain of carbide, the tougher the tool. The higher the cobalt binder, the tougher the tool. Also, steel grades often contain carbides of elements other than tungsten, such as tantalum or niobium (steel reacts chemically with WC). And coatings to improve things like lubricity, or shield them from heat.

Carbide is very hard and it snaps rather than bending. However, it's also MUCH harder than HSS, and FAR less sensitive to temperature. Meaning that it will hold an edge for much longer. A sharper cutter works with less pressure which, in turn, makes it harder for you to break the cutter (this is knife wisdom: often a dull knife is more dangerous than a sharp one because you're more likely to lose control of the blade).

The best cutter is an hybrid / composite ("carbide tip") cutter: the body is made of regular steel and the tips are brazed carbide. Basically a lathe cutter on an helix. It's much cheaper than a solid carbide mill on larger sizes. I still wonder why those aren't more common.

 

[Freenet]

Overall, on my machines, I prefer carbide. Because it is expensive, I use a mix of all sorts of HSS and carbide brazed/solid/indexable tooling.

The conclusion I came to: HSS works on all machines, from tiny to large but carbide works only if the machine can handle it (power and rigidity). For me as a rule of thumb, carbide is the way to go for cast iron, tough steels or stainless and any weld that needs machining. HSS yields good results on non-ferrous alloys and steels. HSS is quite forgiving, carbide is not.

Not all carbide tooling is equal, as not all HSS is. HSS will greatly vary from lowest quality to HSS-E, HSS-PM.
Another important aspect of choosing the right tool for the job would be the presence of cooling.

 

[Batmanacw]

I feel I should mention that I get inserts stupid cheap and use them as much as possible on both the lathe and mill. I don't find insert tooling to be fragile at all. I've never had issues with interrupted cuts.

I'm still an 'all of the above" guy.

 

[dabear3428]

I feel I should mention that I get inserts stupid cheap and use them as much as possible on both the lathe and mill. I don't find insert tooling to be fragile at all. I've never had issues with interrupted cuts.

I'm still an 'all of the above" guy.

I find inserts and HSS to be fragile, but that is a personal problem, not the fault of the tools.

 

[gard]

For solid end mills, I have a lot of sizes in HSS and a few in carbide. My impression is the sharp carbide does not need higher power and rigidity. When I am cutting steel I can use a larger cutter and/or higher speeds with carbide than HSS so it gets the job done quicker with better surface finish. The carbide is taking smaller chips and lots more of them. Not as much of a difference with aluminum. This is just my hobbyist experience with old underpower Clausing mill.
The price of carbide end mills seems to be coming down so I expect to be buying fewer HSS at least in the common sizes.

 

[Batmanacw]

I find inserts and HSS to be fragile, but that is a personal problem, not the fault of the tools.

Anything we can help with? You have a huge bunch of guys here who are very happy to help.

I have a terrible time with carbide threading tools on my little lathe. It just doesn't have the power or rigidity for larger threads. If the belt slips the tip of the insert is gone.