Thread: Carbide

They both look like rubbish, to me. Grab yourself half a dozen bits of HSS and do some grinding.

Thanks for the info, I'll learn as I go along...
I am still new to this so the more input/link/direction the better

Gday Jackaroo

It might help if you let the forum know what type and size your lathe is. Also tell us what you are turning in the way of materials.
The size and horsepower of the lathe indicate what the tooling requirements are needed to be to a certain extent .

Those shown are carbide tipped tools ie:silver soldered to the tool shanks.Chip one and you have to fluff around finding a replacement and get it silver soldered back on and then re ground.

Also something to note is your center height relative to the toolpost.Even if the gap in the toolpost fits the tool shank it may well be too high for center height.( an undersized shank can be shimmed up to center height,but one too big -too high-wont fit without grinding to gain center height).

I believe carbides(indexed or soldered) is not something a beginner should necessarily start with. Article 99 is correct in saying that HSS is better for you to start with .HSS is heaps more versatile and pretty forgiving if you make a stuff up.
Carbides do not tolerate you accidently reversing the spindle direction-the pointy bit breaks off.If you blunt or break the pointy bit on HSS -no worries just sharpen it and go again.

Does this help you ?
Grahame
not a Guru

Hi Jackaroo,

Like you, I too am a novice, and posted a similar question re carbide tipped tools.

Refer to post Carbide tipped tool holder, dated 24th Aug, this year.

I successfully made my own, but with issues. With the correct tip now fitted, it works like a charm on my mini Unimat 3 lathe.

I will be posting a detail drawing and more pics very soon. It was easy to make and gave me a lot of satisfaction in doing so.

HSS steel is also fine, but it's nice to keep up with the latest technology.

Regards,

Ken

Hi All,

Thanks for the tips. My dad just bought a Hafco Al-960B (300mmx925mm) and he is not a machinist himself. and as you said, I broke a few insert tips on reserve!
http://www.hareandforbes.com.au/sample_2/home.php
I am not too sure the HP but I think its 1.5 or 2HP, I'll check on the weekend.

I'll see if I can get a machinist handbook.

I have been mucking around with it. I am building the go kart for my son (so far I made rear axle, bushes and front axle) I am not machine anything that hard yes, just mild-steel, brass, Alu do far)

Hi Zac, I tried to pm you but yor mail box is full. Thanks again

Cheers
Trong

Hi Ken, I just went though your other thread and learned some more. I think I should do some reading on tool geometries first.
One day I'll be there...

Cheers
Trong

I foolishly bought a set of these once, and found they were hopelessly prone to chipping (not good to learn with). You can sharpen them like a regular HSS tool if you have a green wheel for your grinder, but sooner or later you run out of carbide. I use HSS most of time now.

Hi

Yes, they are really a waste of money. However there are good reasons why you could (and sometimes should) use carbide tipped tools.

IF you do purchase such tools it may cost you the same price for ONE GOOD tool as it does for this package of tools. This is good value and if you review the Hafco cataloge you will see some tools at a good price.

If you intend to use these carbide tipped tools on a 1.5/2 hp lathe they should work well. You can take very heavy cuts, ie remove a substantial amount of material with carbide tipped tools as they can handle the high tip temperatures, whereas HSS will easily lose its temper. (no, not get angry ).

When I bought my (now) 58 year old lathe it came complete with a few carbide tipped tools. I use them more or less exclusively for everything (too lazy to change the tool for every job ) If the inserts (NOT BRAZED) tips are sharp they do a good job on most materials. I have even cut some specialised plastics and still managed to retain a good finish.

With my lathes 3/4hp motor I can manage about 0.075-0.090 deep cut in mild steel before the belt slips - I need to replace the motor and adjust the belt arrangement to improve this

This lathe can handle the load, it's just that the motor is too weak. The lathe was originally powered by a 3ph motor - probably 1.5-2hp.

Hi gurus,
Are these the one you are talking about? The lathe is taking 16mm carbide holder so what is the best size of square hss should I use?
http://cgi.ebay.com.au/5PCE-3-L-3-8-...QQcmdZViewItem

What about these? Are they HSS as well?
http://cgi.ebay.com.au/Ten-5-8-Squar...QQcmdZViewItem
Cheers,
Trong

Yes. Those are tool steel blanks. For most work around 13mm and under, a piece of 5/16" properly ground to shape will do just fine. As you get larger diameter jobs, you go up in the size of tools. Using smaller steels on a chunky toolpost is no drama, you just need to make yourself up a tool holder.

Thanks Zac, I'll get some to try out. For the tool holder, is it just something to bring the tip to the center of the work piece?

Its really just a block of steel milled or ground square with a slot in to suit the size of tool steel. Drill and tap a couple of holes to hold it in there and you're laughing. Basically you make the thing so as it sits as close to centre height as you can get it when it's put in the tool holder on the lathe.

Will post a pic of one (after work) I made a while back for holding 5/16" when screw cutting. Much the same kind of thing.