Decent cut-off tool

You didn't comment on your lathe. Won't help much if it's a light duty machine. Parting is a very difficult operation, requiring good rigidity.

Harold

It's an 11x26" lathe from Grizzly, a G9972Z or Zangzhou Supermachine Company Bench Lathe CQ6128A×660

1HP motor.

The only way to go on light hobby machines is to fabricate a rear toolpost, and then mount a cutoff tool upside down. It works really well, but it's quite a bit of effort to do it. I did it on my 9" SB with two kits from Metal Lathe Associates - the T-slot cross-slide table, and the rear toolpost.

GWE

Pardon, but what is a "light" or "hobby" lathe? I can vividly remember getting the bed down into the basement.

Also, Aloris does make a reverse holder for T blades.

Grant Erw>

Having looked at the link, I'm of the opinion that you will have some trouble with parting----likely considerable chatter, and perhaps even the part climbing the tool. It's hard to say with certainty. Not trying to discourage you in any way, just to put you on notice to use caution to avoid crashing. Keep everything as short and as close to the chuck as you can when attempting parting. Light feed tends to be worse than coarse feed where chatter is concerned------and lubrication is mandatory. Do not attempt parting dry---not even with a rigid machine. Few materials will part dry successfully. Spindle speed is likely be quite critical---too slow isn't good, nor is too fast. If you start out too slowly, you're likely to have a ton of trouble, especially with hand feeding. As dangerous as it may sound to you, if your cross slide has feed, learn to use it for parting. If you select a good rate, it will be constant and provide a continuous,uniform chip that won't yield any surprises. Best thing you can do is work a little with the operation and learn what works for you on your particular machine.

A word of caution: Avoid parting mild steel if possible, assuming you do have problems with parting. It is one of the worst materials you'll ever encounter because of its propensity to tear. Leaded steels (or any of the free machining grades) will point out the differences immediately. They are an excellent choice if your application doesn't demand they can't be used.

Grant's suggestion of installing a rear parting tool isn't a bad one to consider, for more than one reason

Luck!

Harold

for what it's worth, I have a 12 inch X 48 inch Logan Powermatic - I don't know if that's light duty as you suggest or not, but it's certainly not a heavyweight industrial monster - it seems to part off fine using the Aloris BXa7 parting blade holder - I haven't tried the carbide insert blades (yet) - the trick, for me, seems to be getting the blade truely perpendicular to the axis of rotation, and learning what speeds work on the lathe - but I can part off 2 and 3 inch stuff (aluminum and steel) ok, though of course aluminum and even brass are a lot faster at least than steel. And I found that hand feeding using a constant pressure seems to work well for me, but then again, this is a sample of 1

Anything under 1200 lbs.

I think my smallest lathe..the Hardinge HLV-H, which is only

9x18...weighs something like 1500 lbs

Gunner

Make that 2. I have a worn 10" South Bend, a good lathe but no heavyweight. I part with a hand-fed Enco HSS blade at whatever (low) speed cuts smoothly, with pipe threading oil from HD fed into the cut with a needle oiler.

303 SS, cold and hot rolled steel cut pretty well as long as there's a little oil flowing but if I stop the oil the blade will jam within about 10-20 Seconds. I keep the belt loose and use low-inertia collets instead of a big chuck if possible so the blade rarely breaks and I can back off and feed in slowly until the rapping noise stops.

I hold the blade vertical when grinding to get a concave surface which is easy to touch up with a hand stone.

I rarely use power crossfeed only because gear train noise blocks out the sound of the tool.

Jim Wilkins

That is light. Carbide part-off-tools are a waste of money for this lathe. You'll ruin more carbides than you want to know.

Get HSS tools and a coolant pump, that will make you happy.

Nick