View Full Version : Starting Over

02-26-2012, 03:23 PM
I'm just setting up a machine shop and could use some direction on my tooling. Do I go primarly the carbide insert route our primarly the HSS route.

I'm going to be doing a fair bit of 6061-T6 work and I see the Carbide will cut a lot faster than HSS, the down side is there is no resharpening. If inserts are the way to go which particular type(s) would you recommend.

Also I'm interested in knowing why you'd use a spotting drill in place of a center drill. While talking about center drills..are the cheaper ones OK or do I need a better grade to ensure concentricity or improved tool life. Any recommendations?

And last but not least for now....tool holder for the lathe, piston or wedge type and why?


The Artful Bodger
02-26-2012, 04:25 PM
Hi, my experience is only about two years since I set up a home shop with almost no earlier experience.

I started with inserts etc then 'reverted' to HSS as I can grind the tools myself and hopefully learn something in the process plus the price of inserts became quite impractical for me.

No doubts inserts are the preferred tools for serious machinists but for a home shop, especially for someone with little or no experience I highly recommend starting (at least) with HSS. Having said that there are doubtless many old hands and professional who use HSS where appropriate.


02-26-2012, 04:38 PM
I'm only repeating what I've heard, but it seems to hold true. If you have older machines they do not turn fast enough to take advantage of carbide tooling. Since I use quite a bit of scrap metal, carbide is good for cutting off the crusty stuff. I get much better finishes with hss, and have more flexibility with cutter profiles since I'm grinding my own.
The other issue, which I haven't seen discussed as much, is the QCTP's holders that are available commercially are usually set up for carbide. HSS needs more relief angle, and those holders aren't as easy to find. Easy enough to make; it's hard to have too many tool holders! I've got a wedge type Dorian tool post, like it alot, but see no reason why a piston type wouldn't serve you equally well.

Black Forest
02-26-2012, 04:47 PM
I'm only repeating what I've heard, but it seems to hold true. If you have older machines they do not turn fast enough to take advantage of carbide tooling.

That is not true with the modern carbide tooling.

Tyro 001
02-26-2012, 04:51 PM
Start with HSS. It's a lot cheaper and it seems like we home-shoppers are always needing a special cutter. HSS is a lot more newbie resistant; the inserts are easily broken. Inserts are great once you learn how to use your lathe, but they do work best with higher speeds and pressure than HSS.

I went with Dorian tool holders. Pricey, but almost indestructible.

Spotting drills are more durable. It's easy to break the little lubricant reservoir part of the center drill. However, if you're drilling a hole for use with a dead center, use the center drill; that's what they're for.

02-26-2012, 04:52 PM
I as well started out with the carbide inserts. I have since 'reverted' like The Artful Bodger. I have found manual machines are more accommodating to HSS. This is a result of not only speeds, but usually a lack of programmable feeds. Even with HSS, you can see a major difference if you are doing a set, defined operation a whole lot rather than onesie-twosies. Carbide's benefits are largely in the former. That said, don't discount that each has their place in a manual shop. I still keep some carbide around for things that it can only do---but the majority of my use nowadays is HSS.

[EDIT:] a response to Black Forest, yes, it is true. Carbide in 2012 is not the carbide written about in books from the 50's. That said, the material is inherently brittle. Even if the cutting edge can deal with much lower SFM or hold up incredibly under good conditions, as you lower the SFM on the cutting tool the brittleness becomes more of a factor, IME. All too easy to chip even if you are familiar with its properties. Unless you're working with a very hard material or other such, I see HSS offering more benefits than carbide in my own shop. Not least of which is price/performance ratio.

[EDIT 2:] Also worth pointing out that all the more likely purchased by a HSM, lower cost carbide-insert toolholders don't really perform that well (read: they don't support as well and exacerbate the chipping issue with carbide). The name brand ones are quite impressively priced in comparison. I guess what I am trying to say is that I found myself feeling like I was throwing money at a problem that was so simply solved--with so much more versatility offered--by switching to HSS for my primary cutting tools.

02-26-2012, 04:58 PM
I use HSS mainly, with carbide when its a tough job. Cutting though abrasive skins on hot rolled, roughing large quanitys of mild steel, Or trying to get a fulgy finish with a insert endmill so that I have a texture to make a clamp work better.

02-26-2012, 05:06 PM
I used HSS for ages, grinding my own all the time. When I got a larger lathe, I was never very happy grinding larger tool material.

Then I came across a complete kit of carbide inserts and holders. This worked very well with the larger lathe, and I use carbide for all bulk work.

I still use HSS for boring, and for special shaped cutters, but my goto tools are carbide inserts.

So I'd advise you to get a (wedge type) post, with a lot of holders. Get a basic set of HSS tools, for cheapness, and then look for some insert holders and inserts at your leisure.

Beware carbide spotting drills - they can chip easily IMO.

Black Forest
02-26-2012, 05:06 PM
I find carbide insert tooling is the most practical for me. I find the tooling I use from Walter to be very durable. The biggest plus for me is the repeatability. When HSS gets dull you take it out of the tool holder to sharpen it. Then you have esentially lost your place regarding distances. Inserts you just loosen the the insert rotate it to a new edge and go on. The only grinding I do is for the cutting tools for my shaper.

I have had no luck with brazed carbide tooling especially threading. I had much better results with HSS threading on the lathe than with brazed carbide. The inserts I bought for threading are great and give me repeatable results.

I use a Multifix tool post and think it is great.

02-26-2012, 05:06 PM
Actually the small diameter tip on a center drill is for the tip of the live or dead center to have clearance, it has nothing to do with lube. Buy a 1/4" and 3/8" spot drill and it will cover most jobs.

Your better off with HSS for turning aluminum. You will need about 15 deg back rake on the cutter for best results and front clearance can be 5 to 10 deg. the side clearance depends on the feed rate. You may be better off with a lantern tool post rather than a QCTP.

If you don't have one buy an older Machinery's Handbook, preferably a #15 to #24 issue because the older ones cover things more for manual machines.

02-26-2012, 05:29 PM
Those that think carbide is the "professional" choice, or that think they do not need to know how to hand grind a HSS bit bc they can plop on another insert need to sell their machine tools and quiet down a bit IMHO. Do not let anyone tell you either of these as they are proving themselves ignorant.

HSS is rather versatile as previously mentioned, in that you can "adjust" the cutting edges to your unique application (though you can too with brazed carbide). Moreover, it does not mind an interrupted cut or shatter/chip like carbide does. Even beyond that, it does not lock you into using a bulky holder of a specific size as with carbide inserts (brazed exempted). Tool holders = PITA when working in tight quarters, as do any of the "quick change/production" style tool posts, but that is an argument which most here argue with me on. When I worked in the prototype shop, and still today, I use HSS for 99% of lathe work. In the home shop, unless youre considering production (which you shouldnt be for a decade or two of machine tool ownership IMHO), you need versatility and not speed. Generally when learning, you also need to keep your tooling costs low due to having few tools to work with, and also need tools that might be a bit "forgiving." Not only is HSS significantly cheaper, its more versatile, and will take more abuse before becoming "trashed." Being that its slower, it will also allow for slower reflexes on your part before "oh crap" moments and crashes occur destroy your machine.

To answer your question of spotting vs center drill. Spotting drills are for starting holes, and center drills are for drilling for centers, spotting drills allowing the more precise positioning and less "wandering" of the drill. Its rather like using a prick punch vs a center punch when marking drilled hole locations.

For the others...my lathe was made in either 1958 or 9, and has no problems using the "old" carbide, though I do typically use brazed carbide over inserts as a matter of preference. Using the phrase "old" when referring to machine tools is rather vague though. Maybe a turn of the 20th century lathe wouldnt like carbide too much, along with the smaller and cheaper more modern machines, but carbide has been around since early? 1940s so I fail to see why what many consider an "older" lathe would have issues running it.

02-26-2012, 05:31 PM
I only use a lathe for hobby work. I use carbide almost exclusively. I have many different profiles and they last a long time. Insert holders are available with every rake imaginable. Don't count them out. I find them very easy to use on my 7x12 and 9x20

The piston style QCTP works fine, but the positioning of the tool is not as precise as the wedge style. The wedge style forces the dovetails to mate by forcing it backward against a fixed piece. The piston style pushes the holder away from the post, thus pushing dovetails into contact 90 degrees form the way a wedge does it.

The end result is that both tools will be easy to use, but one will go back to the same X and Y location while the other may be off by a thousandth or so.


Black Forest
02-26-2012, 05:38 PM
Justanengineer wrote, Those that think carbide is the "professional" choice, or that think they do not need to know how to hand grind a HSS bit bc they can plop on another insert need to sell their machine tools and quiet down a bit IMHO. Do not let anyone tell you either of these as they are proving themselves ignorant.

In my shop tell me why I would need to grind a HSS tool when I can select an insert to do anything I want to accomplish on my lathe or mill. Telling me I should sell my machines because I don't want to grind HSS is once again showing your lack of understanding of what is out there. You alway are spouting off about this and that as being absolute fact. Many time lately you have been proved wrong. You should read your own signature and think about what you write. At least you are amusing!

loose nut
02-26-2012, 06:33 PM
The simplest answer from the average HSM's point of view is that the cost of a half doz. good quality inserts will buy a lifetime supply of HSS in the sizes that most of us use.

02-26-2012, 06:36 PM
I have to side with BF and danlb on this. Unless the carbide being used is the crap collected from the yak dung-ridden parking lot at the Chinese factory or made in 1972 in upstate NY, there's the distinct probability that we may now enjoy:

* carbide that can take low speed interrupted cuts in flame cut crap.
* carbide that is ground so sharp you'll be re-attaching a finger if not careful.
* carbide inserts with an astounding array of geometries, grades and coatings.
* carbide inserts that can be found inexpensively yet offer long life.

It's not for everyone, and HSS will work just fine in almost any routine aluminum, non-ferrous and mild steel application. However, not every home shop guy is so flat broke that a couple of $10 inserts and a $80 holder is out of reach. I know I spend money on some tools I may not ever even use, so carbide insert cutting tools that go right into getting work done are a huge plus. Some people might choose to "plop down" a wad of cash and tool up once.

For me, for instance, I'm still working 50+ hours a week and the shop I share with my dad is a 15 minute drive away. That means every minute I can save by NOT removing a $2 HSS tool to regrind it helps, and the fact that I can get the job done at 2x to 10x the speed matters to me. I have some inserts that I've used over and over again and have yet to index them. It can be that good.

Having these choices and rationalizing for your own situation is empowering. Not being aware of the choices and the opportunities is where ignorance lies.

02-26-2012, 09:52 PM
In my shop tell me why I would need to grind a HSS tool when I can select an insert to do anything I want to accomplish on my lathe or mill.

You alway are spouting off about this and that as being absolute fact. Many time lately you have been proved wrong. At least you are amusing!

Glad you find me as amusing as I often do you. I believe this is the common "blind leading the blind" attitude that PM members often joke about (which has nothing to do with any specific tool or COO btw). I am not the one spouting off something as being "absolute fact." You are the one saying that there is one tool that works in EVERY situation. Also, I cannot remember too many times on this board being proven wrong, and certainly not as many as you yourself have been.

If the operations you do are very common, please feel free to continue to use whatever tooling suits your fancy. My father works on a lot of antique Farmalls. His 12" adjustable is like your carbide, it can do it all (except it cant in reality). Good luck fitting that wrench or using your carbide in EVERY situation. If you notice, I did not say that I use entirely HSS, just that it is used in most situations.

If carbide can truly do everything HSS can, riddle me this...Why is it that on multi-million dollar fully automated machining lines, I very often see HSS? At my own plant, these lines are designed by a team of engineers and tradesmen from both our company and others such as Ingersoll, Mazak, and quite a few other "names" big and small. I should hope they know a bit more about machine tools than you or I.

02-26-2012, 09:59 PM
I use either ,though carbide is about 70% compared to HSS, This wiil get me yelled at by some buy both can be ground to shape for one off cuts , insert holders can be modified or made to work in crowded areas.
It horses for courses , if there is a bit of free time and the material is soft enough hss will be fine , if it is some piece of "should be mild stel " supplied by a customer then I have a grade of carbide which will take some punishment from interupted cuts and alternating hard soft patches in the metal.
Yes inserts will soon add up to a tidy sum sitting on the shelf, however being able to pick one to get a job done so that you make money is better than arguing the pro's and cons of each type.
I am happy to say each has its place and 90% of machine will work with either , speed and HP only make a slight difference .
Keep the cutting tip sharp and both will give you the desired finish.

J. Randall
02-26-2012, 10:28 PM
I have seen it stated here several times that you have to take the HSS out of the tool post to sharpen it, I just don't see that unless you have completely trashed the grind. I just grab my little diamond hone and hit it a few licks and am good to go. I think there is a place for each, but I am glad to have both and use them according to my needs.

02-26-2012, 10:35 PM
I'm going to be doing a fair bit of 6061-T6... If inserts are the way to go which particular type(s) would you recommend.
100% recommend THIS (http://latheinserts.com/product.sc?productId=9&categoryId=88) type of insert. It is specifically meant for aluminum and performs admirably. All the manufacturers offer this type of sharper-edged insert for aluminum. That supplier is fine, but you can get them just about anywhere else too.

tool holder for the lathe, piston or wedge type and why?
Piston type has less accuracy in height. It only pushes out on the dovetail, which can lead to the holder not always seating the same. The wedge type forces the toolholder down and out, which seats the adjustment screw on the toolpost's top edge the same every time (in theory :)). Personally, I feel the price difference between the two types is so small as to not merit consideration. It is one of the most used tools on your lathe. Why not choose the more accurate option for such a nominal price difference?

02-26-2012, 11:16 PM
For what it's worth,not much I'm a newbie. I started with HSS then tried imported carbide & hated it. I'll take the HSS anytime. I turn mostly alum.

02-26-2012, 11:31 PM
I would recommend the wedge type QCTP over the Piston. I have made a complete trip around the "What kind of tool to use question." There is not a right or wrong answer. HSS is very versitle and usefull. You need to be able to grind the tools. I rough on a belt sander and finish on a Baldor tool grinder fitted with a good Alox wheel on one side and a medium Diamond on the other. If you use Brazed carbide you need a good Diamond wheel. You need some Diamond hones and some assorted Arkansas stones. To refresh/sharpen HSS I don't remove it from the holder. Grinding HSS tools is not difficult but there is some learning involved.
Inserts are nice and very usefull. For turning Al they last a very long time. If you don't have some guidance you will buy a lot of tools that you won't use that much. It was a sobering moment one day when I opened a drawer and realized that I had more invested in that drawyer than I did in my Lathe. I probably have 50 tool holders with tools mounted for quick use. I am coming full circle back to HSS for more of what I do. With the insert type tooling I find that there are a few holders that I prefer. I could probably get by just fine with about five holders. Nothing but experience will Identify which you will find most usefull.

Many advocate freehand grinding HSS. As I get older and the eyes dimmer and the hands shaker.... I cheat and use guides made from HDPE. I also do final finishing on a fine Diamond wheel which works good. Many don't believe that is a good idea.

That Aluminum insert referenced above looks good but $58 is out of my league.

02-26-2012, 11:52 PM
:rolleyes: this happens every time some one asks, "carbide or HSS". Most home machinists can get excellent results with HSS and HSS Cobalt. For some things they may want to get some brazed carbide and if they feel the need buy some carbide insert holders.

It's not likely you will see much difference using carbide or HSS as a home machinist. The advantage of HSS is you can grind it to any shape you want and it's cheap and easy to use.

I mostly use HSS, HSS Cobalt and brazed carbide because they can be resharpened easy. I use the insert holders for rough cutting mostly.

It doesn't really matter which you select as long as it does what you want and you can afford it. To say HSS is the only way or carbide is the only way is wrong. Each have their strengths and weaknesses and if you use them you will find out what they are.

All I can say is start with HSS and work your way up from there. What one person likes another will hate and another will like all of them.

If your going to buy a QCTP then buy the wedge type.

02-27-2012, 03:38 AM
IMHO, HSS is preferred to carbide for most turning for a beginner. I'm sure it is a matter of selection, but over half of the 8 or 10 holder insert combinations I have DO NOT WORK as advertised. I have wasted more $ on bad advise on carbides than I have invested in HSS tooling including the 5 full drill indexes beside the various machines in the shop. Before the "you get what you pay for" argument is trotted out, I have low dollar import holders that flat outperform the $150 set I bought at the old GEARS show in Eugene.

Annoyingly enough, the best insert I have found for my bigger lathe is a milling insert.:eek: :rolleyes:

My 0.02 NTL, YMMV

02-27-2012, 01:18 PM
Thanks for all your feed back. I actually got a new Shop Fox lathe and was amazed at the speed range (up to 2400 RPM). It's still in the shipping grease right now (I'm building a bench for it) but I have to say that initially I'm impressed with the apparent quality of it. I'll post more when I get it on the bench and try to get it aligned to my satisfaction.

The reason I was asking about the carbide is that I was looking at the turning speeds and thought for the 6061 when I'm turning wheel hubs I'll have a lot of material to remove and the rate would seem to be significantly higher with the carbide. I get the sense that the answer is both using each type where appropriate.

02-27-2012, 02:03 PM
Experimentation is your friend for that or anything else.

One time I was machining cast aluminum flanges so I got some rejects from them and experimented with different cutters and finally worked out the best approach.

02-27-2012, 02:07 PM
carbide versus hss: this is simple. does cleve have the equipment and know how to grind his tools from hss blanks? ready made tools can be bought, they cost quite a bit and will have to be reground too. (brazed carbide: will last longer, but the same applies.) if not, inserts are the way to go. who says they cannot be reground?

toolpost: well i have a multifix on the big lathe. in viev of the fact, that an original holder sets you back 200 bucks or so and you probably need a dozen of them i would switch to 4-way toolpost any time, if i knew where to get one that big. its faster than a quick change and whats the problem about keeping tools with their shims in some kind of rack anyways?

02-27-2012, 03:44 PM
I have some little Vardex DTMG21.52 inserts that have a high polish intended for aluminum. These things are freaking great. They also work very nice on titanium and if you are careful, steel and stainless. Mirror finishes.

I wholly recommend the D or V series inserts. Their narrow profile allows you to to get in close for detail stuff. The inserts can be used in standard tool holders as well as boring bars. And the profile allows you to turn and face with lots of side clearance without moving the tool which is nice for stringy aluminum.

02-27-2012, 05:40 PM
I use both, but strongly prefer inserts for the lathe whenever possible. My lathe doesn't go beyond 1000rpm, but it\'s a very powerful and sturdy Monarch. As for the Bridgeport, I don't use inserted tools very often. When needed, I may use inserted facemill or endmills, but it doesn't happen often in my hobby shop.

02-27-2012, 05:56 PM
The reason I was asking about the carbide is that I was looking at the turning speeds and thought for the 6061 when I'm turning wheel hubs I'll have a lot of material to remove and the rate would seem to be significantly higher with the carbide. I get the sense that the answer is both using each type where appropriate.

Metal removal rate is also tied to HP and machine rigidity. Some small(er) lathes lack the guts to use a carbide insert to its full potential. At $7+ per insert, the advantages of carbide over HSS sometimes becomes moot.

04-12-2012, 07:49 PM
I do not use insert tooling...damn expensive.Get some HSS blanks and a decent grinder.The best instructions I ever seen,believe or not are on the Sherline website.I have a China 7x12 lathe,its a good little bench lathe,got the 4 jaw,the mill attachment,tool post grinder.Been using this machine for prototyping,tool constructs,etc.Having used that holy of holys,a Hardinge toolroom lathe,these wee china machines work fairlly well with some tuning.Also lighter cuts.

04-12-2012, 10:29 PM
Metal removal rate is also tied to HP and machine rigidity. .

removal rates are mopre than just tied they that, they are determine by HP and rigidity and not much else. If I go half the speed, but 2x the DOC its the same removal rate.

If you're worried about covering overheads use carbide, if you want to control disbursements use hss. I use both but 80-90% of the time its hss. If you know how to grind it and put and edge on it, not sure why anyone wouldn't. up until a few years ago everyone who ever ran a lathe learned how, so its no more difficult than tying your shoes....that seem difficult at first too, right? :)

as for the spotting drill, its the right tool for the job....if you're locating a hole. Centre drills are for drilling centres for turning. The cone they produce is liable to chatter when you start a drill in it (its 60 not 118 degrees) and the pips can break off.

uncle pete
04-12-2012, 11:26 PM
Well I may not be 100% right because I've yet to try every brand of Chinese or Indian built cutting tool on the market. But out of the ones I have tried? Not one will compare to American, European, or Japanese built cutting tools. That goes for both HSS and carbide. Either braised carbide, Or the indexable tips. With cutting tools like anything else, You pretty well get what your willing to pay for. Cheap HSS and Carbide isn't worth buying IMHO. I'll never buy another dirt cheap cutting tool. I can't afford them. But I'll highly reccommend Chicago Latrobe M2 HSS, And Micro 100 braised carbide. Kennametal for replaceable tips, But there's many other good brands. In the long run the more expensive cutting tools last and perform far better. They are a better deal than the cheap crap.

Brand name companys have a real interest in maintaining good customers and do so by producing top quality products. The Wi-Du We Care Flung Dung, Sewage Werks and Precision Carbide producers don't. With cutting tools, There's no such thing as cheap and good quality.


04-13-2012, 05:12 AM
i`m one of those started with zero experience, el-cheapo everything guys.
first thing i got was a QCTP, and the infamous 5 pc. carbide insert set.
later i bought an older lathe from a retired tool and die guy. it came with a large box of lantern posts,holders, and lots of really strange looking HSS bits.

gradually i figured out what those strange shapes were for...

now i primarily use steel, and i have a few really nice indexable carbide tools. haven`t used the QCTP in a long time.

couldn`t be happier. and i`m still cheap.