HSS lathe tools

Hi all, having succeeded in cutting my first screw thread here is the next question. To date I have gone for indexable lathe tools but the finish isn't always as good as I would have hoped so I am going to try my hand with high speed steel tools and all that this entails in terms of sharpening and profiling. Is there anything I should avoid when purchasing a set of say 8 in a box from any of the usual suppliers? Any words of wisdom will be most welcome. Thank you , Iain Pailing

First, if you just want better threads cut at lower speed, buy specific threading tools not a set.

Second, if what you want is an HSS tool to give fast stock removal and good finish, just buy one Diamond Tool holder from Eccentric Engineering. It will do 99% of all your turning jobs, and is very easy to shape and hone the tool. You can also shape the tool for threading. Look at EE's advert to the right.

+1... Have one myself, initially expensive but worth it, alternatively make one, there are a few posts within this forum where you can get a dwg.

George.

Some people are dead against sets, usually because a set will contain one or more tools that are rarely used. Of course if you already know what you need, then it's possible to avoid wasting money. But for a beginner feeling his way I think a set is very good place to start. You get a selection of tools to experiment with and more learning opportunities.

One thing to watch out for is the usefulness of the tools you actually get in the box - some selections are more sensible than others! I own this HSS set from ArcEuro and others and found it very useful with one exception. Being metric I've used all the tools apart from the 55 degree thread. Note that the internal threading tool is 60 degree metric only and this set would waste two tools in an Imperial only workshop. The right and left knives are easily re-sharpened.

John Haine mentions usefully that the diamond tool 'will do 99% of all your turning jobs'. This is well worth considering. However, even though the Eccentric tool has an excellent reputation, I've not bothered with one! The reason is I happen to do a high percentage of grooving, parting, chamfering, threading and boring. The mix of work makes inserts attractive, though as you've noticed, it can be tricky to get a good finish with carbide!

Dave

Personally I wouldn't buy a set from the usual suppliers. Instead I'd buy HSS blanks from a professional supplier. That way you can grind exactly what you want/need. While the various angles to be ground aren't critical they do vary significantly with the material, so a set will always be a compromise. it's perfectly possible to mill HSS with a carbide cutter, so if a lot of material needs to be removed you don't need to spend ages at the grinder.

While I mostly use insert tooling on my manual lathe for general turning I exclusively use home ground HSS tooling on my repetition lathe for production runs with an acceptable finish:

Andrew

Another vote for the Tangential Tool. As a hobbyist as others have said it does 90% of my turning. It is so easy to set to centre height, see the picture in my Album.

I do use carbide for some jobs though without any problems, what tip radius do you have on your inserts?

HSS blanks are cheap enough to play around with and easy to grind for thread cutting 55* and 60* [Even I can do it ]

With a sharp tool,low speed and plenty of lube,you cant go too far wrong.

Give it a try,you might be surprised !

As someone who has succumbed to buying THREE sets of tools over the years (two carbide tipped and one HSS), only to find that there are some tools which are never used, and that the HSS set is still wrapped up and has never been used, spend your money on a double ended grinder and a few HSS blanks. You will learn a lot more, your HSS blanks will last "for ever", and you will save money as well.

Also, may I suggest that you consider the size of tools you need. Although it might seem a good idea to buy the largest your lathe can handle, it just means more material to grind away whether on initial grinding or when re-sharpening. Someone, somewhere, has suggested that 1/4inch or 6mm along with packing are probably adequate for most amateur turning.

I find that the right hand knife tool does the majority of my turning, followed by an internal boring tool (of which I have three - all different sizes, and a homemade narrow parting off tool. I find that the parting off tools supplied whether in sets or not are too wide for my lathe and cause chatter. Occasionally I might use a left hand knife tool. The vast majority of my thread cutting is metric, for which I use a homemade 1/4 inch silver steel tool, and very occasionally larger tools in both metric and imperial.

Good luck,

Peter G. Shaw

As with everything there is cheap HSS and there is good HSS so you may not get the best results playing with poundland blanks, there is a reason Eclipse toolbits cost tens times or more than Bangland ones.

Thanks for the replies to my query. I should say that the thread cut has an excellent finish and the lathe was used on the slowest speed possible. My opening line was merely a comment on the generous assistance given when I was having problems initially.

The replies indicate the sensible way ahead is to get individual tools as they are needed rather than a set which will contain tools which may be an unnecessary waste of space. I envisage using the purchased items as patterns for making my own from hss tool blanks. At least that way I will have a baseline to start from as I have only used indexable tools so far.

The radius of the inserts may be partly to blame for the less than ideal finish as those currently fitted are not classified as 'finishing/polishing' grade.

Although the EE tool looks very interesting, I can't justify the purchase for the amount of use it would get - however that is not necessarily set in stone!

My wife is presently buying the diamond tool holder from EE as one of my Chrissie prezzies.

If the reports on the forum are true - as I strongly suspect they are - I am expecting that a whole bunch of my current cutters maybe surplus to requirements! I definitely prefer to sharpen a blunted cutter than buy another tip.

I made a 'L' section support that allows me to use 1/4" square-section HSS toolbits, sized so that a 10 thou or so grind on the top surface will be on centre height. So I can grind interchangeable toolbits with tips of various shapes and rake angles - inside and outside rads, thread forms, angles, left- and right-hand knife profiles. I've found the HSS sets have only one or two tools I'll use in unmodified form - I end up grinding them to something I do want. And I have to say that in at least one case I've found their HSS suspect - it wore very quickly in a sort of crumbly, crystalline fashion that I've never seen in a simple square-section blank, wherever it may've come from.

Concerning tool size, the only part of the tool that does any useful work is the bit actually in contact with the material. The rest of it is just there to hold it in place. It follows that for most amateur use where cutting depths are quite small you only need a small tool blank - 1/4" or less most of the time. With the Diamond tool holder people report taking giant cuts with a 1/4 tool bit. Though it's pricy to buy, it's quite easy to make one - look at the Mike's Workshop page for an easy design.

+1 for the Eccentric Diamond Tool.

made a couple of lookalikes using 1/8 and then 5/16 toolbits, and ended up buying the Eccentric version for 1/4 toolbits.

Sharpening is an absolute doddle. Just one face to grind, and setting to centre height, with a centre height gauge is simple. A good surface finish, and freshly ground will take a cut of 0.0005".

Now, only use replaceable tips for roughing or boring. MUCH cheaper and less chance of dropping the tiny Torx screws!

Howard

The OP mentioned screwcutting. How easy is it to get the 55 or 60 degree angle on a toolbit for the Eccentric Diamond? At first sight it doesn't look straightforward, and might require quite a lot of material to be ground away owing to the depth of the front face in this configuration.

The main point I think is that we all come to our own solutions over time, and circumstances and work type are at least as important as toolmaking techniques and purchasing decisions in determining which shortcuts - if any - work well for us.

HSS sets are not hugely expensive, no more than buying a grinder and a handful of HSS blanks.

I think it's worth a beginner getting such a set as (1) they can get started straight away, (2) it eliminates one possible source of problems, (3) the tools are generally easily resharpened, (4) they provide a guide to the required angles when you do come to grind your own tools and (5) they are a source of HSS for grinding your own tools - you can start by grinding tools at the 'back' of them.

I wouldn't advise anyone NOT to learn to grind their own tools in the longer term.

Neil