Im looking for info/advice on hard threading. I have some parts that I'm going to have to hard thread out of powder metal, they will be around 50RC. the thread size is 3/8-24. Threading before hardening is not and option as we were given a written set of instructions on how to make the parts (they are for test samples). They will be done on an Okuma Genos L400 and are about 3 inches long when completed, threaded area is abou 5/8 long. Thanks
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Largest Manufacturing Technology Community on the Web
Stay Connected:
Hard threading
- Thread starter mrdeeds50
- Start date
- Replies 10
- Views 1,497
ChipSplitter
Titanium
- Joined
- May 23, 2019
- Location
- Maybe
Keep the SFM down. Make sure you keep taking enough of a chip to keep the part from workhardening, but not so much that you chip the tool. There can be a fine line between hard/tough carbide grades in this application. I would personally lean toward tougher with lower SFM and a heavier chip load.
Good Luck!
Good Luck!
gregormarwick
Diamond
- Joined
- Feb 7, 2007
- Location
- Aberdeen, UK
Sandvik make CBN threading inserts for hard threading, they work well as long you don't overload the point.
266RG-16VM01A001EE 7015
266RG-16VM01A001EE 7015
Shop Supply Guru
Hot Rolled
- Joined
- May 3, 2016
- Location
- Ohio USA
The CBN might not be bad but I think you can get away with Carbide. Carmex makes laydown threading inserts with a HBA coating that is rated for up to 62 HRC. Here's the price I would charge on them. Part # 16 ER 24 UN runs $12.85 each comes in box of 5. PM me if interested.
gregormarwick
Diamond
- Joined
- Feb 7, 2007
- Location
- Aberdeen, UK
I haven't done a huge amount of powder metal turning, but I have done some.
My experience with it has been that the hardness is only a part of the equation, while abrasiveness is a huge factor.
A box of your Carmex inserts is cheaper than a single Sandvik CBN insert, but I'd still go with the CBN.
Shop Supply Guru
Hot Rolled
- Joined
- May 3, 2016
- Location
- Ohio USA
Did you try carbide first? What was your results? Like a part an edge type? Trouble holding size etc? i'm curious.
Worrying about "work hardening" something that's already hardened is an unnecessary redundancy. (Waiting for the grammar police...)
R
Jashley73
Titanium
- Joined
- Jan 24, 2013
- Location
- Louisville, KY
Powdered metals do act different in regards to hardness, at least in theory. The idea being that the "overall" hardness of the parts may be 50HRC. But, the particles/carbides are much, much harder, thus the description that they're 'abrasive'.
As a general rule, sometimes you can go with an alternating-flank infeed, to spread the wear along both edges of the insert. Personally, I'd try a hard carbide grade with a PVD coating first. (I don't even know if you can find CVD coated threading inserts
) If you can't get acceptable tool life, then CBN
As a general rule, sometimes you can go with an alternating-flank infeed, to spread the wear along both edges of the insert. Personally, I'd try a hard carbide grade with a PVD coating first. (I don't even know if you can find CVD coated threading inserts
) If you can't get acceptable tool life, then CBNgregormarwick
Diamond
- Joined
- Feb 7, 2007
- Location
- Aberdeen, UK
Main problem with carbide was rapid flank wear. CBN might not be always necessary, but it just makes the job go smoothly.
