Carbide inserts for steel usually have a negative rake hone on the edges. It does not perform well at low speed or for light cuts. If one must use inserts buy those intended for aluminum. They have a positive rake and polished surface. It is unfortunate that so many opt for carbide right from the beginning. HSS is more versatile in that the cutting angles can be optimized for the job at hand. Is it a matter of being afraid to mess up grinding a tool? Are they to lazy to learn about tool angles?

I started using HSS on my 10K South Bend then switched to carbide inserts. Now I am using HSS in tangential holders for much of my turning. On the larger lathe with 6 hp. I use mostly carbides.

I would tend to agree with John. Restricting yourself to insert tools depending on what you are making restricts what you can do, for example trepanning a small recess in a face, turning small radius curves (too small for a radius attachment), machining a groove with a semi circular root, the list goes on. The ability to grind up a tool for a specific purpose on the off hand grinder including form tools will save time, money and frustration in either trying to find a suitable insert, buying it and waiting for it to arrive!

All tooling has its place, HSS, brazed carbide, inserts and holders etc. Reliance on pre shaped and ready sharpened throwaway tooling is undoubtably restrictive.

Dont forget that the advantage of the ability to grind a tool is not limited to the lathe alone! It opens up possibilities for fly cutters on the mill, tools for a shaper and you can even make your own spot facing tools for pennies and not be restricted to proportions available off the shelf.

Paul.

I do, but nobody wants to hear that lol, they fall in the etc category of my post.

Paul.

Yes; all these cutting tools are made from carbon steel:

I don't know why people get so partisan about cutting tools. I use insert tooling, HSS and carbon steel as appropriate to get the job done. But then again I'm an engineer, not a modeller, so I'm happy to buy/grind/make tools as needed without fervour.

Andrew

The right tool for the job is the one that provides the required end result.

As already said, if a tool is needed that is not one of the standards available, you have to make your own, so HSS or CS become essential.

They are invaluable at 8:00 pm on a Saturday night when the last carbide insert chips!, on a VERY urgent job.

Don't know of a 1/8" dia Carbide rod, but a short piece of 1/8" diameter HSS cut a 4 mm pitch semi circular thread when I needed one.

Older machines, being designed before the advent of Carbide, are not really suited to get the best out of carbide (Lack of speed or rigidity, or both )

My favourite for much work is a HSS tool bit in a Tangential Turning Tool. (Have 1/8, 1/4 and 5/16 versions ).

EASY to sharpen using a simple jig.

Carbide inserts get used for roughing, boring or radius work, Especially if the steel is hardened. Lovely to see the blue /brown, or red hot chips coming off!

Horses for courses

Howard

I disagree.

Some low carbon steels are better with bigger DOC, but by no means all. Speed often has more of an effect, faster is better. I rarely run coolant with inserts. Although I have flood coolant available it gets thrown everywhere at high spindle speeds, and in most cases doesn't help the finish. For 1" diameter low carbon steel I would be running around 800rpm. This post, with quantative results, may be of interest:

Turning Trials

Andrew

There was a time when the Chinese bucket shops advertised everything as High Carbon Steel because it sounded good. Unfortunately, poor quality control made it synonymous with shattering under load. Now they call everything carbide. Carbide suggests Tungsten Carbide but it could also refer to iron carbide, aka high carbon steel.

Call me Mr Suspicious. Fortunately, this does not keep me awake at night