I have a Colchester Bantam lathe and carry out fairly basic machining for which I grind my own tools in HSS. However as I am not particularly good at grinding tools I am contemplating moving over to indexable lathe tools. I have found a few sets ranging in price but do not really know what I should be looking for.
The materials I am working with are free cutting mild steel and ally.
Does anyone have any recommendations based on what they have used or know someone has used?
An option I was looking at is this 9 piece 15mm tool height set
You are using the right tools for mild steel and ally with the HSS Just keep at the grinding the more you do it the better you get. I am not sure were you are but if you are not to far from North Lincs I could help you.
I would give that particular set a miss.Assuming that like most people you are turning,facing and boring,you will find nothing in that set that can be used in the correct way for facing and boring and only one tool that is ideal for turning. Now some people may say that you can swing the toolpost to make some of the other tools usable,and it`s possible you could, but it would not be ideal. Look at the big tool company websites and see which tools can be used for different applications.They all have a little schematic with arrows at each particular tool showing in which direction they cut.That will give you a better understanding of what`s available. Look for Sandvik,Iscar,Seco,even Kennametal.Nothing wrong with Kennametal tools but their website is one of the worst to navigate.Carbide can be used ok on a small lathe like a Bantam alongside HSS. Mark.
I use indexable tip holders and inserts from Greenwood Tools on my Myford. If you're looking for cheap, this is not the place to go, but I've found them helpful people selling high quality stuff. I'm not very good at sharpening HSS, and I find the tipped tools work for me on almost everything. I can run faster than with HSS and once the centre height has been esablished, I can keep the same packing with the tool for perfect setting every time.
I have one tool for turning and facing, another that takes the same tips for boring, and a parting off one.
I marvel at friends who can take a lump of my HSS and sculpt it into a thing of beauty, with mirror-shine edges that cuts like a dream. I must practice more.
I would second Mark's comments regarding the above set. I made the same mistake on my Dad's behalf and although the tools work, they're not convenient. For a useful and comprehensive catalogue go here:
and download their 'turning catalog' (sic). It gives the standard designations of tool holders and tips
There was a comprehensive and well reasoned dissertation on the subject of carbide tips by Dave Baker a year or more ago, but the main element was that for our use, avoid coated tips (typically yellow coloured), use ones quoted for alloy, even when cutting stainless.
Yep, I followed Dave's advice on inserts for alloy and haven't regretted it.
Inserts for alloy make ordinary inserts seem blunt - as indeed they are, being designed to push through steel under high power with minimal wear rates, rather than the less powerful cutting we do where wear rates don't matter much.
Well worth a read if you can find it somewhere like
- in fact the whole thread is worth a read.
Another advantage of inserts-for-ally is that they are ground to complex shapes, with a a "hook", which is really hard to do on hand-ground carbide. For this reason I've pretty much given up on hand-ground carbide in favour of inserts, except for some boring bars.
I still prefer HSS for brass, bronze and mild steel, for stainless it's about even, but for copper, monels and inconels inserts-for-ally win hands down. That's on a minilathe.
One extra note for beginners to carbide, carbide is not like HSS - it's brittle, and not very strong. Interrupted cuts, banging into jaws etc (even when stationary) are all likely to cause a crunch where the carbide edge shatters.
You will break a few edges before you understand how this works, but after a while the rate of breakage does go down a lot :)
As a raw beginner myself with only a year or so's experience of turning I'm a bit puzzled that you find grinding HSS difficult enough to consider giving up and moving to commercial inserts. Usually it's fear of the unknown that creates premature failure (as others on this thread have eloquently ranted about), but as I understand it you've had a go and the tools have been unsatisfactory.
Can I suggest that the instructions on the Sherline website are worth trying?
This is what I used to dispel my initial terrors. After grinding the first couple of tools, I stopped worrying about Sherline's suggestion of setting the tool rest at an angle and just lifted the blank up "a bit" from the horizontal rest to set the rake.
Like you, I mostly work with Aluminium or free-cutting steel. Grinding my own tools from HSS blanks I've never, ever, made a tool that doesn't cut and produce a decent finish. I very much doubt this is because I am God's gift to machining. It seems much more likely that it's because lathe tool grinding isn't super critical, at least not for the stuff hobbyists do. Other things like having an adequately rigid machine (such as your Bantam), getting the speeds and feeds right within a factor of two, and so forth, seem to have more influence on the end results than whether the tool rake is 7 degrees or ten degrees.
Oh, and to the poster who suggested that using inserts avoided the need for grinding up HSS tools, I offer my last week's problem of needing to cut a circular channel in the base of an optical centre punch to contain
3/4 of a 0.1" dia O-ring (to stop the base skidding about on the workpiece and scratching it). Maybe there's an insert for doing this, but I bet you wouldn't normally have one in the box. Grinding an HSS tool looking a bit like a miniature parting tool took just a couple of minutes and had the job done in no time.
Richard Shute wrote: here was a comprehensive and well reasoned dissertation on the
I have replied elsewhere, but I missed one point: aiui, the meat of Dave's advice was not "avoid coated tips". it was "use tips meant for aluminium" - which are usually silver-coloured and shiny and look uncoated.
Whether they are actually coated or not isn't really relevant.
Tips for aluminium tend to have a sharp geometry, which is what we as hobbyists need.