I bid a small job. It consists of a 50 units consisting of 4 parts. A 2" long union, made from ½" hex with 1½" of that length turned down to .437 using a 45º cutter, the inside of the union 5/16-24, half RH and the other half LH. Not a problem, whizzed right thru those. A locknut, which was just a standard hex nut, So I bought a bag of them. The other 2 parts of the unit are just threaded rods one 2.750" long with 1.750 of the rod being threaded RH and another rod 4 3/4" long and 1.375" of it threaded LH. I didn't have the chasers for the die head, so I used a 1" round die in a floating head in the tail stock of my manual 12 x 36 lathe. I machined the RH rods and only 5 didn't meet my QC, but it didn't take long to make the extra 5. All the threads are nice and burr free and a nice snug no slop fit.
I am using 4140 5/16" rod from McMaster Carr with lots of threading oil. I didn't have a LH die, so I bought one from M-C. When I got it in, it was Irwin brand, USA made. I figured since the die was new, and my RH die I have been using for 5 years or more and it cut perfect threads, this new LH die would do the same., so I started using it to do the 50 LH rods. The threads are horrible. Lots of burrs and undersize threads, especially at the beginning of the cut, so my question to y'all is, what could be causing this? I looked at the teeth inside the die and all appear to be intact (not chipped or broken, etc.) and a nut fits the threads decently at the end of the cut, but why all the galling,burrs and undersized threads? Thanks for any advice one can give. I got to finish this job ASAP if not sooner !!!
I am using 4140 5/16" rod from McMaster Carr with lots of threading oil. I didn't have a LH die, so I bought one from M-C. When I got it in, it was Irwin brand, USA made. I figured since the die was new, and my RH die I have been using for 5 years or more and it cut perfect threads, this new LH die would do the same., so I started using it to do the 50 LH rods. The threads are horrible. Lots of burrs and undersize threads, especially at the beginning of the cut, so my question to y'all is, what could be causing this? I looked at the teeth inside the die and all appear to be intact (not chipped or broken, etc.) and a nut fits the threads decently at the end of the cut, but why all the galling,burrs and undersized threads? Thanks for any advice one can give. I got to finish this job ASAP if not sooner !!!
