Can you make a parting tool using HSS blanks?

[mikey]

I have a parting tool and parting tool holder, but it won't stick in my QCTP well. I got the blade at least. I just need to find a way for it to stay in the QCTP and stay parallel to the chuck.

You can grind parting tools from square blanks but it is a lot of work. You need about 5 degrees of relief on both sides and 5-10 degrees of front relief. Best way is to rough it out with a tool grinder and then use a fixture to accurately grind the side relief with a surface grinder. Assuming you don't have the equipment to do this, using the parting tool you say you have is probably the best bet.

I am unclear as to what you mean by "... it won't stick in my QCTP well." Perhaps you can clarify what kind of tool you have and what your problem is in more detail. Seems to me that sorting this one out will be easier than grinding a tool from a blank.

Just an aside but if you are not using a P-type parting blade, you should try it. I use a P1-N mounted upside down in a rear mounted parting tool holder on my Sherline lathe to part stock up to 2" OD at high speeds with no chatter or dig ins. This P1-N blade is only 0.040" thick and I've never broken or bent one. It has parted everything from Delrin to 4140 to O-1 steel without a whimper. I use a P1 or P2 on my larger Emco lathe and part from the front, again without issues, so I happen to favor these kinds of blades. I also have an Aloris inserted carbide parting tool that works well but it has a 1/8" thick insert - wastes a lot of material.

 

[pdentrem]

There is uneven wear on the ways. The majority of the wear is usually in the first 6-10” closest to the chuck plus the width of the carriage. If one adjusts the gibs to tighten at the chuck end the tail stock end ends up being tighter to too tight. Have to compromise on the gib settings.

As for making parting tool, if only using HSS blank, I would use a 1/2” blank not a small 1/4” one.
Post a picture of your tool post set up please.
Pierre

 

[bfd]

you don't need to grind the sides perfectly parallel in fact you need to add some clearance on the sides front to back and clearance on the sides top to bottom but this tool will have limited depth of cut. I have seen some parting tools on this website made from cutting up an old woodsaw blade ( like a table saw blade this gives you a carbide tipped parting tool worth a try I have never done it. looked interesting bill

 

[Asm109]

You grind with a bit of relief so the tip is the widest part of the cutter.. If you are parting off the exact width of the cut is irrelevant. Free handing is plenty accurate.
If you are trying to cut a groove for an oring where width is important you do one of two things.
Make cutter narrow, plunge then move the carriage over and plunge again OR
grind the cutter slowly and measure the width frequently with a micrometer. grinding is slow and it is easy to just take a thou or two at a time.

 

[royesses]

I have a parting tool and parting tool holder, but it won't stick in my QCTP well. I got the blade at least. I just need to find a way for it to stay in the QCTP and stay parallel to the chuck.

does your parting tool holder look like this?

This is the parting blade I use $7.95 from LMS. It works fine.

That hoder is flat from top to bottom and the P1X blade it a t shape so the blad only makes contact with the holder at the top of the tee. When tightened up it will stay in place. You can also shim up the bottom so it will stay at the proper distance from the holder. I milled a groove in my holders so the whole blade sits flat against the holder and the T sits in the groove. I had to use a carbide end mill since the LMS holders are hardened. It burned up a HSS end mill.

Roy