Critical to Quality All The Way Out the Door

CNC machining liners

In a typical production machining operations the quality focus is generally on the process and procedures that occur while parts are being produced. But, the quality management system doesn’t end there. Ultimately the shipping department is the final line of defense in the quality process ensuring great parts that have been produced are delivered safely and on-time. While machining custom parts that meet exacting customer specifications is Heartland’s core functionality our dedicated shipping team is responsible for the following steps, right up to loading parts on trucks, that are critical to quality;

  • Deburring – Sharp edges are dangerous and unacceptable on machined parts. Our shipping department is the gatekeeper ensuring parts are appropriately deburred before they are shipped. This ensures that parts are received safely at the customer location ready for sale, integration into an assembly, or the next machining operation.
  • FOD Prevention – A final review for Foreign Object Debris (FOD) ensures parts are shipped without articles or substances on / in them which could potentially cause damage. While FOD prevention is critical for aerospace applications it’s also applicable for any finished parts regardless of the industry.
  • Assembly – Most multiple component assemblies, based on customer required, are completed within our shipping department.
  • Stamping, Marking & Identification – Heartland ensure that all customer required information per their specification is stamped onto individual parts. Our shipping department utilizes dot peen direct part marking which provides the following advantages;
    • Permanent marks
    • Good marking depth
    • Highly visible mark
    • Low-stress marking

Upon completion and prior to shipping the stamping content is double checked by our quality team.

  • Individual Part Packaging – Preparation and packaging of each piece always meets customer requirements that may include; rust prevention, individual packaging, sleeving parts, wrapping in specialty wax paper, etc.
  • Packing – Parts are packed as efficiently as possible to meet customer specifications. We ensure that each box / crate is sturdy and durable with cardboard protection inside to ensure parts do not come in contact with each other during transit. Heartland has a full woodshop that enables us to produce custom packaging for the secure transit of diverse sized parts.
  • Loading – Safe transport from the shipping area to the loading dock and onto awaiting trucks is critical. Securing the load in the carriers trailer can reduce any unnecessary transit damage.

While shipping is a prerequisite for any manufacturer it’s taken to the next level at Heartland. We take pride in ensuring that the parts we produced arrive at our customer’s facilities on time and in the same high quality that they left our facility.

Heartland Honing for Cylindricity

precision metal honing

At Heartland Enterprises, we have extensive experience operating honing equipment that improves the geometric form and surface texture on pipes, tubes, cylinders, and liners.  In honing operations, a rotating tool carrying abrasives removes metal from the interior surface of a bore or cylinder. The main purpose is to finish the surface to a particular diameter and geometric cylindricity. It’s almost always a secondary machining operation that finishes a part or relieves stress. A typical production cycle is to rough turn the OD, bore the ID, hone, finish turn and complete any required mill work. The honing operation typically removes from 0.001” to 0.010″ (0.03-0.3 mm) of material.

Although the honing process can be applied to any surface, it is most commonly done on internal cylinder walls using a combined rotating and reciprocating motion. Low cutting pressure, low velocity, and relatively small amounts of material removal characterize it. Typical speeds are around 250 fpm (76 m/min). However, unlike conventional machining, higher speed is not always an advantage. Each application has a honing abrasive chip load which is a limiting factor. With abrasive honing stones, the proper choice of bond and coolant optimizes stone performance and cost per part.

We typically utilize abrasive stones that are used along a controlled path to remove minute amounts of material in order to attain almost perfect cylindricity on parts. Unlike conventional machining, the accuracy of a honing process is not entirely dependent on the machine. The tool and abrasive are the keys to accuracy. Another difference from conventional machining is that it needs no chucking or alignment. The part aligns itself with the tool because the tool or the part is floating in most applications. Often, the part is placed in a specially designed honing fixture that provides floating action.

Honing machines allows precise size, surface finish, roundness, straightness and consistent surface texture to be achieved. And with our equipment we can achieve surface finishes between 6-8 RMS with tolerances as tight at +/-0.001″ or meet virtually any customer specified requirement.  Our facility is equipped with a Sunnen Model HL 80 precision horizontal hone that handles diameters from 3″ to 22″ with a 60″ stroke.  We also have a Sunnen Model MBC-1805 hone with auto sizing and power stroke capability; accommodating diameters ranging from .160″ to 3.5″ with a 6″ stroke.

A Natural Gas Compression Legacy

heartland in process liners

Since Heartland’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 Heartland has significant experience machining to print parts for a diverse group of players in the natural gas compression market.  Over almost 30 years Heartland 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 Heartland 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 Heartland can take on a wide variety of production parts for your organization.

Better Threads Lead to Better Rods

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 Heartland has been machining rods with rolled threads for oil and gas applications including; Natural gas compressor piston rods and Frac pump stay rods.

Specifically Heartland 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 ½ – 8 UN or 2 ¾ – 12 UN.

Heartland Enterprises Now ISO 9001:2015 + AS9100D Certified

precision machining capabilities

We are ecstatic to announce that Heartland Enterprises has upgraded to ISO 9001:2015 and added the AS9100D certification. The achievement of this milestone was a team effort driven by our quality assurance manager.

While there are many reasons we decided to pursue the additional AS9100D certification the primary reason simply is that it will make us better. Heartland’s primary objectives have been and will continue to be;

  • Taking care of our customer
  • Taking care of our employees.

AS9100 widely adopted and standardized quality management system for the aerospace industry will propel Heartland to the next level as a leader in the machining of highly engineer parts. The new standard will help up better achieve our primary objectives of continuously meeting the needs and objectives of our customer and employees in the following ways;

  1. Increased customer satisfaction: The AS9100 standard requires a focus on understanding customer requirements so that we can better meet their needs.
  2. Raising the bar: AS9100 is the internationally recognized standard for Quality Management Systems for aerospace companies and it is the default expectation for customers.
  3. Improved decision-making: AS9100 embeds our top management into the Quality Management System, and champions making decisions based on evidence and data rather than vague attitudes.
  4. Increased efficiency: AS9100 is based on the process approach to understanding how we provide products and services, and emphasizes understanding how these processes interact.
  5. Engaging employees: By defining and mapping the processes, and involving the people within those processes in the activity, we will not only ensure that our processes are functioning as expected, but we can engage our workforce towards the goals of process improvement and customer satisfaction.
  6. More robust supplier relationships: By focusing on mutually beneficial relationships with suppliers, we will find ways to work together in order to improve customer satisfaction.
  7. Habitual improvement: One of the principles that is ingrained into the AS9100 requirements is the need to find ways to make the management system incrementally better over time, a process called continual improvement. By making improvement a part of our daily business, we can harness the power of our engaged workforce and focus them on finding ways to make the processes that they are involved in better, faster, and cheaper to run.

As one of only ~10,000 certified organization world wide Heartland looks to expand on our past success while taking care of employees and old and new customers alike.

Overcome the Fear of Nickel Superalloys

large diameter shaft turning

Challenges and Methods for Machining Advanced Superalloy Materials

The conventional wisdom that nickel superalloys are difficult to machine, whether by cost or failure rate, is rooted in a flawed approach.   Overcoming the difficulties in machining nickel based superalloys is important since they exhibit beneficial characteristics including excellent mechanical strength, resistance to thermal creep deformation, good surface stability resistance to corrosion or oxidation, and their application in extreme, typically high temperature, environments.

Inconel, Hastelloy, Rene, and Waspaloy are nickel superalloy materials utilized as load bearing structures across a number of industries. Example applications include; pressure vessels in petrochemical plants, parts for downhole shafts and wellheads in oil and gas production, biomedical applications and rings, discs and shafts for the hot section of turbine engines. The preeminence of superalloys in aerospace is reflected in the fact that they currently comprise over 50% of the weight of advanced aircraft engines.

Challenges Machining Nickel Superalloys

A flawed approach is that stakeholders including machinists, engineers, designers, process planners, etc. treat these advanced materials like high strength, heat-treated alloys. While similar in physical properties nickel superalloys and heat-treated alloys are fundamentally different at the literal cutting edge. Heat treated materials have a higher tendency to chip and break away under shear forces, like those used by the cutting tools in machining processes. Challenges associated with machining nickel superalloys that all stakeholders should be aware of include;

  • High nickel content leads to work piece hardening.
  • Compressive and shearing forces attack the cutting edge resulting in tool wear and deformation.
  • Frequent tool changing reduces productivity.
  • Removing outer scale from nickel superalloy forgings that are not uniform creates interrupted cuts.
  • Roughly twice as much machine power is needed compared to cutting low-alloy steel.
  • Drilling large diameter deep holes is slow and requires lots of machine power.
  • Material movement, including warpage or dishing, demands machining in multiple operations.

Using nickel superalloys as a manufacturing material requires stakeholders to understand the issues nickel presents. The material does not weaken or deform at higher temperatures, as observed with other types of alloys, therefore nickel is more difficult to deform using typical high precision machining processes. This has kept some from utilizing nickel superalloys even though they may be superior materials depending on the application.

Methods for Machining Nickel Superalloys

Nickel superalloys strength qualities are more uniform with shear, tension, and compression forces resisted. There is no weak point that can be taken advantage of for the cutting process. Simply put, nickel superalloys require higher quality tools that are rigid enough to handle the material. With this in mind, the following tactics can be applied to successfully machine these advanced materials;

  • Consider ceramic tools that are extremely heat resistant.
  • Maintain tool edges to minimize heat buildup, excessive tool wear, and plastic deformation.
  • Optimize cutting speeds to the maximum surface feet per minute (SFPM).
  • Counter work piece flex using rigid setups between tool and work piece.
  • Use the maximum quantity of cutting fluids for heat removal.
  • Operate without coolant to remove forging scale. With the correct grade of ceramic insert this strategy can anneal the material in front of the cutting tool.
  • Optimize a robust, rigid steady rest to support longer nickel superalloy shafts.
  • Rushing nickel superalloys cycle times will result in wasted insert edges and potentially ruined tools.

Approached with the right plan, nickel superalloys can transform the strength profile and heat resistance of a part without incurring excessive costs. Overcoming the stereotypes surrounding these sometimes frustrating materials requires preparation to understand the material specifications, budgeting appropriate job time, and selecting CNC machining service providers with extensive nickel superalloy experience.