Screws

Answer:  Rolled screws are produced using a cold forming process; therefore, the steel must be relatively soft (<222 BHN).  Rolled screws have minimally higher tensile strength, shear strength, and fatigue resistance compared to machined screws because the natural grain structure is free of interruptions.  In addition, the thread finish is higher due to the burnishing effect [...]

Answer:  Yes, 4140 HT lead screws have excellent uniformity of hardness, resists creep in temperatures up to 1,000 0F (538 0C) and have good wear resistance and toughness. Relatively speaking, materials with high surface hardness levels exhibit greater wear resistance. In lead screw applications equipped with metal nuts, this translates into longer operational lifetime. Nut materials are [...]

Answer:  It depends on the type of screw, as follows: Single-Thread ACME Screws:  1-4-ACME-4C-LH x 144 indicates a centralizing class 4C ACME thread of 1-inch major diameter, 4 threads-per-inch, single-thread, left-hand thread and 144 inch overall length.  The hand designation is not required for right-hand threads. Multiple-Thread ACME Screws:  1-0.25p-0.5L-ACME-4G x 144 indicates a general [...]