The Team at Keystone Threaded Products shows us that “Precision” doesn’t necessarily mean “Tiny” as they thread the ends of some 20 foot long, 10 inch stainless steel bars for a Metalworking press. The thread is a 10-1/4″ : 4 UNJ RH applied to each end of the 3 and a half ton bar.
At Keystone, they roll the thread form onto the material which makes for a stronger thread. Alignment and following the process is critical to assure a good thread.
Multiple passes are needed to build the thread up to the proper dimensions.
Obviously it takes knowledge, skills, and experience to apply half million pounds to produce precision work.
Here’s another look at a finished bar. Precision does not necessarily mean tiny!
Thanks to Betsy Minnick and the Team at PMPA member Keystone Threaded Products for showing us that “Precision” is not a synonym for “Tiny.”
Tag: Keystone Threaded Products
Because the steel grain structure is cold forged, rather than cut, rolled threads are up to 30% stronger…
While the strength of a thread is a function of section thickness, a thread rolled rather than cut thread is usually superior in mechanical properties, all other things being equal- here are 6 reasons why:
- The flow of the material by cold work during rolling reinforces the shape.
- The cold working strain increases mechanical properties, Surface Hardness,Tensile Strength, Yield Strength, and the Yield Strength / Tensile Strength ratio.
- The surface finish of the thread flanks is usually smoother due to the burnishing action of the rolls.Smoother finish means better fatigue life and fewer opportunities for stress risers.
- There is more material (section thickness). This results in material savings*, since the diameter of the blank will be between the major and minor diameter of the thread, rather than greater than the major diameter for a cut thread.
- The compressive stresses on the threads resulting from rolling improves the fatigue life.
- The root of the thread has a smoother radius, improving fatigue life.
Pictures courtesy PMPA member Ray Industries
Click here for a video of the thread rolling process in action from PMPA member Rolled Threads Unlimited LLC.
*I got my first “learnin” on rolled threads at my customer Keystone Threaded Products back when my hair was not silver and B.K. (Before Kids): “Why do you always buy funny sizes Jim?” I asked. That was a great first lesson on how engineering can add savings: