Black Oxide Finish

POSTED BY , Manufacturing Processes

Black oxide is a common coating typically applied to iron and steel. It is created by immersing the part in an oxide salt solution at approximately 285 degrees F. While mostly applied to iron and steels, it can be applied to nonferrous metals such as aluminum under suitable conditions. It cannot, however, be applied over plated parts (e.g. chrome, zinc, nickel, etc).

Black oxide on steel provides only marginal corrosion resistance. However, when applied to stainless steel or brass alloys, it will provide exceptional corrosion resistance even in harsh environments. Black oxide will not provide a smoothing effect like painting or painting. Any surface imperfections present in your substrate will still be present in your black oxide coated part.

A supplementary coating can be added after the black oxide process is performed. This coating, called an “after-finish”, will dictate the appearance and corrosion resistance of the coating. Without the after-finish, black oxide has poor corrosion resistance.

Advantages to black oxide coating include the following:

  • No dimensional, physical or mechanical changes to material properties: black oxide changes the color of the surface metal – it does not add or remove any material from the metal
  • Dark black color: can be a matte or shiny black depending on the surface finish of the substrate, and the type of after-finish applied
  • Additional coating for increased protection: normal after-finishes are Oil, Wax, Lacquer, and Chromic Seals. These can improve the appearance, abrasion resistance, and corrosion resistance of the part
  • Improved lubricity and anti-galling characteristics: an oil or wax after-finish is used to achieve these properties
  • Weldable: black oxide does nothing to diminish a metals weldability, and does not produce noxious gases when welded
  • Will not chip or rub off: must be removed mechanically by abrasion or chemically by etching
  • Innexpensive: one of the least expensive methods of corrosion resistant or decorative coatings

Rapid Prototyping

POSTED BY , Manufacturing, Manufacturing Processes, Prototyping

The climax of any new product design is actually making the product. In the development phase, this can be scary for a number of reasons. Perhaps you’re undecided between several different features or combinations of geometries, or maybe your manufacturing capital is limited. Manufacturing costs, especially in prototype quantities, can add up quickly. Luckily, a technology has developed over the past decade or so that makes prototyping quick and downright affordable. It’s called rapid prototyping, or just “RP”.

The field of rapid prototyping (or RP) has grown tremendously over the past 10 years. RP is essentially a 3D printing process in which a thin slice of your product (typically between .001″ and .005″ thick) is created, and then another layer on top of that, and then another layer on top of that, and so on until your entire part has been built up. This provides you with a geometrically accurate part that can be handled and evaluated. No matter how many views of the product you see in CAD on the computer screen, actually holding the product in your hands is essential to evaluating its form and function.

There are limitations to RP parts, however. Arguably the biggest limitation is the fact that RP materials are much weaker than production materials such as hard plastic or metals. However, the relative speed (usually a couple of days) and low cost (anywhere from $50 to several hundreds of dollars, usually) are such huge advantages over traditional prototyping methods such as soft tool casting or machining that they outweigh the shortcomings of material strength. Besides, RP parts are not meant for full production uses, but rather as a preliminary step to verify your design is accurate and functions properly.

Pipeline has developed strong relationships with local and out-of-state RP vendors and works with them on a regular basis to provide quick prototype to its customers. Contact us here to discuss your project and how RP technologies can help you quickly validate your design.


Predicate Devices for New Product Inventions

POSTED BY , Manufacturing Processes

One of the ways Pipeline helps its customers is by providing an understanding of the vast array of manufacturing processes, and pairing the appropriate process with the design intent of a particular product. Many inventors like to do as much work as they can on their own before handing the reigns over to us. We encourage this, and work with inventors to facilitate it. One of the best tools an inventor can have when developing the high level concepts for their product is an understanding of common manufacturing processes. But how does one learn about these processes and which is most appropriate for a given design?

One of the best ways we’ve found for those interested in matching their product to an appropriate manufacturing process is to look at competing predicate devices already on the market. When you’re talking about spending thousands of dollars to develop your product, it makes a lot of sense to spend $50 or $100 to purchase an existing product that is similar to what you want to develop and deconstruct it to understand how it was manufactured. This will help you understand what process might be the most cost effective for the type of product you’re working on: plastic injection molding, machining, welding, thermoforming, etc. Each of these processes has tell-tale signs that can be derived from a cursory inspection of the parts made through the process.

For a good book on learning more about common manufacturing processes, check out Manufacturing Processes for Design Professionals.


Low Cost Tooling for Plastic Injection Mold Parts

POSTED BY , Manufacturing, Manufacturing Processes, Prototyping

Those who are making their first foray into product development are often shocked at how expensive it is to develop and manufacture even a simple product. Plastic injection molding is one of the most common manufacturing methods used for mass production of physical products. While the engineering and product development of these products can easily cost $5k – $10k, these development costs can often be just a small fraction of the manufacturing costs. High grade steel is typically used as the material of choice for production-quality plastic injection mold tooling. It is expensive and difficult (read “time intensive/$$$”) to machine. The image below illustrates what a common set of tooling (referred to as the “core” and “cavity” halves) looks like:

Hard Steel Tooling for Plastic Injection Mold

As you can see, the innards of the tools are filled with a variety of features necessary to create the required geometry of the part being molded, and creating this geometry is labor and time intensive, costing anywhere from the low $10ks to more than $100k. The savvy product developer will be reluctant to spend this much capital on tooling for a product design that may not have been fully tested and validated yet. Often times rapid prototyping can be exploited to produce general evaluation parts, but these parts are not as strong as their production-grade parts would be, nor do they have a clean, finished, production-quality appearance. So how do you bridge the gap between cheap, crude “RP” parts and finished, expensive production parts? There is, in fact, a third hybrid approach many people don’t realize exists. It’s called soft tooling (see image below).

Soft Tooling for Plastic Injection Mold

Soft tooling gives you the strength and appearance of production parts without the high tooling costs. Since soft tooling is typically made out of silicone or urethane, the raw material cost is dramatically reduced and the core and cavity geometry is much simpler to make. A set of soft tools can run between $500 to a few thousand dollars depending on the complexity of the part. Your part prices will be higher than the injection molded counterparts since soft tooling typically employs manual labor to pour the plastic resin, but if all you’re looking to do is make half a dozen parts for evaluation or presentation purposes, this will save you A LOT of money.

Pipeline Design & Engineering works with several companies who can provide soft tooling molds that produce production-quality parts. Contact us today to evaluate your project and see how soft tooling can save your project money.


How Strong Are Welds?

POSTED BY , Manufacturing Processes

A common concern of engineers when designing parts intended to be welded together (weldments) is how strong the welded joints will be. Performing computer simulation (FEA) on beams or other structural entities is relatively straightforward, however, it can be more difficult to get reliable simulation results on welded joints due to the many variables (weld thickness, skill of welder, type of weld and process used, etc). The short answer is, assuming your joint is designed properly and you have an experienced welder performing the work, your welded joint will be as strong as the base materials it is joining.

There are two main types of welding: MIG (Metal Inert Gas) and TIG (Tungsten Inert Gas) MIG

MIG welding creates an arc between a continuously fed wire filler metal and the workpiece. Shielding gas protects both the molten metal and the arc from the atmosphere. This process is suitable for most metals and alloys, such as the following:

  • carbon steels
  • low-alloy steels
  • stainless steel
  • 3000, 5000, and 6000-series aluminum alloys
  • magnesium alloys

Other alloys that can be MIG-welded via special methods include the following:

  • 2000 and 7000-series aluminum alloys
  • high-zinc-content copper alloys
  • high-strength steels

TIG welding produces an arc between a nonconsumable tungsten electrode and the workpieces. Inert gas is used to shield the arc and the work; filler metal is optional. Like MIG, TIG can be used to join most metals and alloys, but produces higher quality welds because of the absence of weld spatter. Unlike MIG, TIG can be used to produce fuse-welded joints without filler metal, resulting in minimal eruption above the base metal. Welds can be made in all positions, but the process is considerably slower than other welding processes. Compared to MIG, TIG typically takes a minimum of twice as long to complete the same type of weld.

Keep in mind that the strength of a weld will be determined in part by how clean the base materials are before the weld is created. Make sure your workpieces are free of foreign contaminants, oil, grease, etc. Typically, cold-rolled steel parts require little cleaning, while hot-rolled steels may require special cleaning. Aluminum alloys require wire brushing or etching before welding to remove oxidation and produce the highest quality welds (which increases total costs).


Laser Cutting for Product Development

POSTED BY , Manufacturing Processes

As its name implies, this manufacturing process is a cutting technology. There are many fabrication methods to cut materials, and laser cutting is one of the most commonly used. There are no tooling costs, and unit costs are typically relatively low. Many materials can be cut with a laser: wood, paper/card, marble, textiles, rubber, ceramics, and a variety of plastics and metals (steel is especially suited to being laser cut, although other metals such as aluminum can be cut, as well).

One advantage of laser cutting is its ability to create small and precise cuts, so that intricate patterns or details can be made in the material. Like most manufacturing processes these days, laser cutting can be performed via CAD/CAM software: simply send the manufacturer a 2D format (commonly a .dxf file), although including a 2D engineering drawing, as well, is good practice to convey critical dimensions/tolerances or other important notes. While the process is very effective for thin materials (down to ~.008″), thicker materials can be cut, as well (up to ~1.50″). Cutting thicker materials can greatly increase processing time, however, which in turn increases costs.

Pipeline Design & Engineering works with several laser cutting vendors in Arizona and out of state. The process is one of many that allow us to provide superb product development services.

Here are a few images of laser cutting in action.