stub acme

there is a relief at the end of the acme threads so i could thread half then turn it around and cut the other half, picking up the thread would be the same either way.Good idea, i may give it a try. also i could thread the other thread where it attaches while chucked that way. Will wires bottom out being a stub? havent figured the size yet but i could probably get away with some 3/8" drill rod and bridging the gap on the bottom with a piece of tool steel. thats how i do double leads. Thanks alot!
Also as a side note, I've been doing manual machining for 33 years.(same company,papermill) Never be afraid to ask questions!
 
Why 316 SS? Nothing about a lathe lead screw cries out for that. I'd buy a chunk of Stress proof long before I used 316.
 
Why 316 SS? Nothing about a lathe lead screw cries out for that. I'd buy a chunk of Stress proof long before I used 316.
this is a jack on the fourdrainer of a paper machine. its wet all the time, has to be stainless
 
Not familiar with paper mill operations that much. What I do know, the water used in processing can be very corrosive in some of the processes. That's the reason for using 316 SS. It's either this one or go to a duplex stainless steel. The 400 series is probably out of the question. The PH series may work, be a little bit easier to cut in the 2H1150 condition for 17-4PH. I'm sure the paper mill has gone thru all of the options of materials over the years and settled on 316 ss.
On the wire size to use, you may have to cut a flat on the wire so it will clear the root of the thread. 3/8" drill rod will be too big. Need something in the range of .3125 to .3440". Ken
 
Not familiar with paper mill operations that much. What I do know, the water used in processing can be very corrosive in some of the processes. That's the reason for using 316 SS. It's either this one or go to a duplex stainless steel. The 400 series is probably out of the question. The PH series may work, be a little bit easier to cut in the 2H1150 condition for 17-4PH. I'm sure the paper mill has gone thru all of the options of materials over the years and settled on 316 ss.
On the wire size to use, you may have to cut a flat on the wire so it will clear the root of the thread. 3/8" drill rod will be too big. Need something in the range of .3125 to .3440". Ken
i tried .3125 today and it bottomed out, i know i can grind a flat. I looked up the stub acme chart in the machinist handbook, and it gave a range of .318-.428 for wires on a 1 1/2 lead stub acme. I will just be doing a comparison check with the old shaft so i don,t think it would matter much. I do have a stop nut to check the threads. And yes the water is very corrosive. the fourdrainer is where they spread the slurry on the wire and start sucking the water out of it. Were a coated paper mill and everything is bleached and enhanced for brightness etc.
 
Another good selection for steel for high chloride and acidic environments is Inconel 925. You think 316SS is tough to cut, this grade is right there with it, too!
 
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