CWM adds value to die castings: with capabilities to prototype, machine and assemble diecast components, Chicago White Metal Casting caters to customers by adding value from start to finish.

Some casting firms know how to keep up with their markets. Others know how to stay ahead. From increasing its customer-base to implementing new capabilities, Chicago White Metal Casting Inc. (CWM), Bensenville, Ill., is one that leads the diecasting community by focusing on adding value to its components.

A custom production firm, CWM does more than simply diecast components. It stays involved in the total production process from start to finish by integrating operations--prototyping, machining and subassembly--that draw CWM's customers again and again. Although the expansion of these non-diecasting capabilities is relatively recent in the company's history, it has helped to significantly broaden CWM's customer and market base as well as its revenue.

Even during the recent economic slide, CWM has maintained production by supplying to a variety of markets and providing these value-added options before and after the diecast parts are created.

A Humble Birth

Founded in 1937 in a downtown Chicago loft as Chicago White Metal Ornamental and Mechanical Products, the diecasting firm has kept its business strong with consistent expansion into new markets, new alloys and facility space. Originally founded as a maker of zinc ornamental products, such as lamp bases and door handles, CWM saw a growing market for aluminum parts in the mid-1950s. By 1970, the company had increased its capacity to four separate buildings within a tight city space, and management knew they had to relocate.

In 1977, CWM decided to build a new, modern plant and brought its operations under one roof at a five-acre site in the Chicago suburb of Bensenville. A year later, the company became the first custom producer in North America to establish a hot-chamber magnesium diecasting department based on the faster-cycling machines.

Since then, in-house prototyping, CNC machining and complete product assembly has been added to augment diecasting, allowing for more customer interaction, accelerated production and lower project costs.

CNC, FDM Prototyping

To gain a better grasp at the early phases of product design and production, CWM saw a competitive advantage in advanced prototyping techniques. The company honed its expertise with CNC machined prototypes in the early 1990s. Although these prototyped parts are machined from billet stock, they can closely approximate a potential diecast alloy's performance in a range of functional tests. With dimensional accuracy replicating the future cast part, multiple CNC prototypes can be produced to tight time schedules at reasonable costs.

To gain a greater competitive edge during the bidding stage of a project, the company took prototyping a step further in the mid-1990s and added fused deposition modeling (FDM) to its capabilities.

When CWM quotes selected projects, it can create an FDM copy of the part from a customer's CAD file in less than a day. "We can make an FDM model prior to a meeting with a prospective customer," said President and CO0 Eric Treiber. "When that prospect enters the meeting and sees a prototype of the part on the table, they are impressed." When a project goes forward, these FDM prototypes allow CWM engineers to mark up an actual model for critical tolerances and draw its parting lines and ejector pin locations, with suggested minor feature modifications that could significantly reduce production costs. Once the final design is approved, CWM will create multiple FDM parts for their toolmakers, production engineers, quality assurance department, and the post-casting finishing team.

During the toolmaking process, this results in eliminating errors and shortening leadtimes. Using the FDM models, production of trim dies can begin without waiting for first-piece production, as can construction of fixtures for post-casting machining and masks for surface finishing, if such operations are required. These secondary operations now can begin immediately when the first volume production run is completed.

Before FDM, Chicago White Metal outsourced prototypes as stereolithography (SLA) models, but this proved inefficient--both more costly and time consuming. But a substantial investment in the FDM equipment has paid off tenfold, according to Treiber.

Alloy Selection

CWM diecasts aluminum, magnesium and zinc components in the most widely used alloys, with automated cold- and hot-chamber processes.

The aluminum department (which accounts for 40% of the company's sales) features a 30,000-lb. (13,607-kg) and 10,000-lb. (4,535-kg) gas reverberatory furnace, fed by molten metal truck delivery. After incorporation of internal reclaim, the alloy is transferred into a bull ladle that is brought by conveyor to any of the 10 cold-chamber machines ranging 200-800 tons. The main alloy cast is 380, with 360 holding a small percentage of the business. The company can produce aluminum parts measuring up to 24 in. (61 cm) in volume and weighing up to 10 lbs. (4.5 kg).

When the tools are in place and the parts are cast, a robot will remove the solidified part from the die (for aluminum and zinc machines), or the die will automatically eject the component (for magnesium machines) and let it slide down a conveyor where it will go through a manual trim die finishing station at each machine before it is placed in a bin for additional machining, painting, etc. (if needed) and final cosmetic audits. Average casting run sizes are 1,000-2,500 parts, with runs up to 30,000 possible.

From 1995-2000, CWM invested in the rebuilding of all 10 aluminum machines, which included new hydraulics, shot-end systems, electronics, etc., at half the cost of purchasing new machines. "Many of the parts we produce have very tight process parameters, and we are focused on achieving consistent machine operation to allow us to manufacture at optimum efficiency," said Treiber.

A new addition that is expected to increase part quality with faster cycle times is the installation of vertical rotation extractors for the aluminum casting machines that remove the castings from the die while simultaneously spraying the die for the next casting. If this initial test proves positive, the automated units will be placed on all aluminum machines, followed by expansion to the magnesium department. It is expected the extractors will increase cycle times by 20%.

The company's zinc operations (20% of its business) utilize Zamak 3 alloy ingot and reclaim melting in a 10,000-lb. (4,535-kg) central furnace and also utilize the bull ladle conveyor delivery of metal to each hot-chamber diecasting machine. The zinc machines, all refurbished, range from 150-500 tons. Zinc components can be cast up to 20 in. (50.8 cm) in volume and weigh up to 8 lbs. (3.6 kg). In a move to broaden its markets, and spurred on by the demands of current customers, CWM also is in the early stages of casting miniature zinc parts. To expand zinc production capabilities, CWM began offering miniature zinc and ZA-8 zinc alloy components and sales have grown steadily over the last five years.

CWM operates the largest custom hot-chamber magnesium department in North America. This department (40% of its business) produces parts to the same size and weight specifications as its aluminum department. Since no magnesium reclaim is used, only high-purity AZ91D magnesium alloy ingots are fed into 1,000-lb. (453.5kg.) furnaces at each of the 14 hot-chamber magnesium machines. These machines, ranging from 80 to 650 tons, include three 650ton Frechs, among the world's largest hot-chamber magnesium units.

Machining and Subassembly 

Once produced, castings that require finish machining operations are delivered directly to CWM's conventional machining or CNC machining departments. The 35 conventional machining centers are used on high-volume components with medium-level complexities. Here, fixed spindle heads machine multiple points of a casting at the same time.

Looking to offer more machining capabilities and flexibility, CWM expanded into CNC machining applications in 1992. Currently, 25 CNC machining centers are used for parts with higher complexities and to perform operations on lower-volume cast components. CWM, which also performs precision machining for many non-diecasting customers, plans to replace the oldest CNC machines at regular intervals during the next several years.

The addition of comprehensive product subassembly capabilities also has proven to be advantageous. Begun in the mid-1980s, CWM management foresaw future customer interest in single-source responsibility for the assembly of mechanical and electromechanical products. CWM's subassembly operations began as a limited service to existing customers, but have grown over the last 10 years into a separate company division, with equipment investments totaling $500,000.

To meet the requirements of a complete assembly, CWM offers customers total responsibility for the custom production of components in any process, the procurement of all stock parts and the completion of all assembly steps through final packaging.

"Today, many more of our diecasting customers are asking CWM for services that allow them to concentrate on their core competency and focus on lean manufacturing," Treiber said.

"For example, a company that has us cast a housing for a new wireless device may not wish to gear up for the efficient procurement and assembly of the related mechanical parts required to complete the final housing. They prefer to receive the casting assembly, ready to go directly into their final assembly line and have a circuit board laid in place." Treiber also stated that the firm can offer an OEM reduced time to market and lower costs, and the subassembly operations have increased the company's revenue by 50%. "It is a proven way to increase sales without putting all the burden on the individual diecasting departments," he said. "We strongly promote that aspect of our business."

Hitting the Market

Telecommunications, electrical-electronics and medical firms have been key CWM customer segments, but Treiber said market categories now tend to intertwine with the pervasive use of electronics in a wide array of products. Telecommunications products and medical devices actually are just a combined 15% of the company's business, as CWM's market-base has expanded. This helped the company significantly after the decline of the telecommunications boom in the 1990s, when many OEMs found themselves with sharply reduced demand. This was followed by many of CWM's customers in that industry outsourcing to foreign diecasters. Today industrial and commercial products represent the largest share of CWM's sales at 23%.

The company has controlled its revenue through recent tough times because of its job-shop philosophy and its 300-plus customer base. "There are a few--projects we lost overseas," Treiber said. "Fortunately, many of the markets we serve have been less susceptible than others. As a custom producer we strive to make sure no single industry and no individual customer is ever a dominant portion of our business."

In a given year, one customer will entail at most 8-10% of CWM's sales base, and 30-40% of the company's products are shipped to international customers. Treiber said this is the result of adhering to a business approach of not relying on a single market. "You have to achieve balance," Treiber said. "If revenues are aligned strongly with one market, and that segment declines quickly, the results could be fatal."

Setting the Path Ahead

Currently, CWM has plans to tap into new markets for castings as well as promote CNC machining to customers whose quantities are too low for die castings. Within the last five years, the company also has explored offshore tooling capabilities to serve domestic customers who face implacable competition and demand minimum tooling costs to sustain their customer base. CWM will continue to utilize the skills of their outstanding domestic toolmakers. Despite concerns from some of their domestic tooling sources, most have agreed with CWM's new sourcing evaluation procedures, which give preference to domestic firms for all improvement work on existing dies.

"If we do not consider building a mold offshore, we may never get that bid from the customer who requires a minimum cost tool." Treiber pointed out. "And as a result, the domestic toolmaker will have no opportunity for possible retooling work on a future design change."

With expected business expansion, the company's operations could soon outgrow its present facility. However, foresight five years ago led the company to purchase 110 acres of land west of its current location. Although no construction has taken place, CWM is planning the design of an entirely new building on this site when the time comes to expand.

"Every day we are looking for ways to do our job better, smarter and faster" Treiber said.

Chicago White Metal Casting Inc., Bensenville, Illinois 

Year Founded: 1937,

Metals Cast: Aluminum--A360 and A380; Magnesium-AZ91D; Zinc--Zamak 3.

Casting Processes: Diecasting.

Melt Capabilities: Gas Reverbatory and Electric.

Size. 136,000 sq. ft.

Key Markets: Telecommunications, Electrical, Electronics, Industrial, Commercial and Medical.

Employees: 150.