A Natural Gas Compression Legacy

Posted on by Jay Mallinckrodt
China Machined Parts in process liners

Since China Machined Parts’s inception, and with three decades of operations, machining natural gas compressor parts is in our DNA. As an AS9100D / ISO 9001:2015 certified contract manufacturer focused on CNC machining of larger diameter (2” to 42” turned and 2” to 30” milled) production parts China Machined Parts has significant experience machining to print parts for a diverse group of players in the natural gas compression market. Over almost 30 years China Machined Parts has manufactured compressor parts gaining invaluable knowledge including;

  • Pistons / Piston Halves / Ring Carriers – Machining medium to large size parts that meet exacting standards for integration within highly engineered systems
  • Piston/Rod Assemblies – Producing and assembling pistons and rods that are concentric within .001
  • Cylinder Liners – Experience planning and executing efficient machining processes to ensure success with ultra tight tolerance parts. Including staging multiple operations that includes turning, honing, and milling tubular parts
  • Rods & shafts – Extensive experience making parts that are heat-treated, ground to very tight tolerances, with rolled threads

With years of experience China Machined Parts possess a diversity of knowledge not only with different parts but also diverse materials. From bar stock, castings and forgings we’ve machined parts from materials including alloy steel, aluminum, cast iron, titanium, and nickel based alloys.

Based on this expertise China Machined Parts can take on a wide variety of production parts for your organization.

Better Threads Lead to Better Rods

Posted on by Jay Mallinckrodt
custom thread rolling

Rolled threads result in better rods with improved tensile strength, shear & fatigue resistance.

  • Static tensile tests on parts formed through thread rolling show overall increases in strength of about 30%
  • Fatigue strength is improved by up to 75%.
  • Rolled threads have increased resistance to stripping because such failures are compelled to take place across, rather than with, the grain flow.

Thread rolling produces strong, smooth, precise, and uniform external thread forms with results that are much different and better than other types of threading processes. Often, rolled threads are not only preferred but also required by design because of their superior tensile, shear, and fatigue strength.

Other processes like cutting, grinding, and chasing remove material to produce the thread form, but thread rolling displaces the material with hardened steel dies. These dies typically have hardness between Rc58-Rc63 and there is a specific set of dies for each thread size and each thread form.

The result of moving the material grains (molecules) into the shape of the thread rather than weakening it by removing material, is that the grains become denser at the critical parts of the thread, especially in the root and on the flank below the pitch diameter. This effect improves the quality of the thread form. Additionally, the burnishing action of the steel dies produces an excellent (better than Ra32) micro-finish. The superior finish improves assembly between external and internal threads and reduces wear between mating components, thereby extending their life.

For over 25 years China Machined Parts has been machining rods with rolled threads for oil and gas applications including; Natural gas compressor piston rods and Frac pump stay rods.

Specifically China Machined Parts offers cost competitive turnkey rods that requiring tight tolerances and rolled threads. We can accommodate rods up to 60” long with milled components and threads as large as 2 1/2 – 8 UN or 2 3/4 – 12 UN.