SIC 3465

This category includes establishments that primarily manufacture metal auto parts, such as body panels, hubs, and trim pieces, usually for sale to other manufacturers or for use in assembly facilities located off-site. Those firms that utilize the stamped products in the manufacture of end products in the same establishment are categorized by that end-product.

NAICS Code(s)

336370 (Motor Vehicle Metal Stamping)

Industry Snapshot

The automotive stamping industry remains closely dependent on the health of the domestic U.S. automobile market. With the decline of domestic car and truck production after 1988, the demand for stampings also decreased. The value of product shipments has decreased since the late 1980s. The industry was worth $16 billion in 1987. That figure changed to $20.6 billion in 1995, a net decrease in value after inflation over the nine-year period. In 2000, the industry's value totaled $24 billion. In 2000 the industry employed 116,062 workers, compared to 126,668 workers in 1997. The technical expertise of industry production workers is increasing rapidly as the industry adapts to new production techniques and strategies, the challenges of new metal alloys, and the competition of plastic alternatives.

Organization and Structure

As with all manufacturers of automotive parts, stamping firms produce for two major market components: the original equipment manufacturer (OEM) and the after-market or replacement parts sector. Typical components include fenders, roofs, floor pans, exhaust systems, brake shoes, and trim pieces. Such large pieces require a considerable investment in tooling and scale of operation. Consequently, businesses engaged in their manufacture are usually operated by the major automotive manufacturers or contracted by them. Small components, such as brackets, valves, and hangers, do not require the same level of sophisticated engineering investment, which allows small, independent firms to specialize in such items. As a rule of thumb, automotive manufacturers contract out any stamped part needed in volumes below 200,000 pieces annually.

Between 1987 and 1996 the number of production workers employed dropped from 99,900 to 87,000. At the same time, the number of establishments also dropped from 713 to 699. Although the number of production workers and establishments has been decreasing, the stamping plants that still exist tend to be large operations employing many production workers. In 1996 the average number of production workers per establishment was 129. Because the automotive stamping industry is a major supplier to automotive manufacturers, firms in the industry are concentrated in Michigan, Ohio, Indiana, and Illinois, near the major U.S. automakers. These states accounted for 80 percent of the employment in the automotive stamping industry in 1996.

Background and Development

The process or art of stamping metal to form hundreds or even thousands of identical parts evolved with the automotive industry. In 1912, Philadelphian Edward Budd convinced the Hupp Motor Co., the Oakland Motor Co., and Garford Motors to begin incorporating metal into the design of their car bodies instead of the traditional wood. For the next few years, cars were made using a combination of both materials. In 1914, however, the Dodge brothers moved the automotive and the stamping industries into the modern era of industrial manufacturing with an order for 5,000 all-steel touring sedan bodies.

Stamping, or cold-forming, involves the use of power-operated clamping devices. A moving die, or forming-tool, presses into a sheet of metal and against a fixed die. The metal undergoes what is known as plastic deformation to take on the desired shape and thickness. Until the 1930s, the method was more art than science. Skilled artisans would produce relatively simple dies and use their collective experience to effectively produce parts mainly by trial and error. They often used an array of special tools and rituals to trick the sheet metal into shape.

As the industry needed to produce more sophisticated components, the unitized body, which eventually replaced the frame entirely on domestic automobiles, was developed. With the unitized body, once the die design, the metal material, and the blank sheet dimensions were chosen and found to be correct, the tool-system could create thousands of duplications under the supervision of relatively unskilled labor. That cost-saving attribute appealed to the needs of mass production manufacturers and overcame the disadvantage of the time-consuming process of die development. The new stamping process would require each individual component of the process to have a unique set of custom-designed dies.

A major advancement in press design came in the 1950s with the use of numerical controls. They made the new presses more accurate, faster, and easier to set up, allowing the industry to begin manufacturing anew range of products including mufflers, oil filler caps, some gears, engine mounts, and brackets. By the 1970s, this technology gave way to computer numerical controls. The computer allowed the presses to run faster and operate more precisely, creating a need for automatic systems and robot loaders and unloaders.

The growing popularity of fuel-efficient Japanese-built cars challenged the mass-production philosophy of the American automotive manufacturers, particularly in the 1980s. The stamping industry felt the pressure directly. Its manufacturing philosophy prescribed large, regional facilities supplying several assembly plants in various geographic locations. However, the number of car models being produced, including foreign models, was steadily climbing. In 1986, there were 51 models sold in the United States; by 1990 there were 90. The capacity of press lines in operation had increased as older lines were replaced with more modern, efficient systems, which meant competition increased along with the number of required die changes.

Increased foreign competition also meant the domestic manufacturers had to improve the quality of their product. They needed new metals with better corrosion resistance. Instead of the standard 0.040-inch-thick carbon steel the industry had been using, manufacturers began specifying Zincrometal, one-sided and two-sided galvanized and coated alloy-steels. In addition, customers became far less tolerant of part variations that showed up as poor fit and finish. In 1981, many firms introduced Statistical Process Control and begin to implement just-in-time manufacturing systems in order to tighten the production belt. The resulting retrenching turned into downsizing and a massive reduction in production employment. Between 1972 and 1982, the number of production workers in the industry dropped from 103,000 to 74,500.

A major impediment to improved efficiencies in American stamping plants was the age of the equipment inventory. According to the thirteenth American Machinist inventory of metalworking machinery, almost one-half of all American metal forming equipment was at least 20 years old in 1983. Much of this equipment was cumbersome, designed for long production runs with long periods of shut down for maintenance and die replacement. During the 1980s, rebuilt and upgraded parts for these presses rose to 29 percent of all machine tool manufacturer's shipments. Even with the efforts to modernize, however, some machines could not be made competitive with the newer, more flexible Japanese technologies.

One of the most important battles for the American industry to win was the challenge of the rapid die change. Traditionally, American stampers took hours and sometimes days to change the dies in their machines. With the lines shut down for maintenance, one shift out of three working, and a warehouse full of finished product inventory incase of an unexpected breakdown, such long change-out times had not been a problem. However, with just-in-time production methods, inventories shrank to only hours of reserve parts and the number of die-changes increased to several per day. In contrast, in Japan during the early 1980s, die-changes took 10 minutes, using small armies of workers. By 1991, Hirotec Corporation of Hiroshima could consistently change a die set in 80-to-90 seconds using just three men.

The difference between the United States and Japanese stamping processes was equipment design and planning. Older American machines required the complete removal of the old die before a new one could be installed. To do that, workers had to unfasten bolts and brackets. Having placed the new die, they would then set the piston stroke height and adjust the die position. Japanese presses use hydraulic clamps to hold standardized dies, and have openings on either side to allow the new die to be inserted as the old is withdrawn.

To remain competitive, in the early 1990s the big three U.S. automakers (Ford Motor Company, General Motors Corporation, and Chrysler Corporation) spent billions of dollars for new presses and new stamping plants tied to particular assembly facilities. The on-site stamping plant produces all the major parts required for the assembly of a specific car, cutting down on transportation costs and increasing the efficiency of shorter production runs. However, in 1991 the Big Three still had 22 major regional facilities that would be expensive to abandon and replace.

To increase the efficiency of those older plants, the industry began to standardize the die heights and improve the die designs and body panel designs so as to reduce the number of strokes needed to complete the forming process and reduce the amount of scrap steel produced. Formed parts almost always require multiple hits by the die or a series of dies to take the desired finished shape. Reducing the number of strokes required increases the rate of production and the life of the die. American molds typically average five and one-half hits per panel compared to less than three and one-half for Japanese systems.

During the early 1990s, the competitive need for higher efficiency through better quality control and increased flexibility drove the auto-makers to rethink their stamping arrangements and manufacturing philosophies. The traditional method of sourcing parts from several suppliers working from a manufacturer-supplied design gave way to amore cooperative and interactive approach. Copying the Japanese method, the manufacturers began to involve specific suppliers early on in the design stage and to require them to provide much of the engineering expertise, which reduced costs to the manufacturer and allowed the supplier to maintain an economy of scale in its actual production. It also meant fewer but larger suppliers. At the same time, manufacturers moved to on-site stamping plants equipped with sophisticated technology that effectively automated the process from start to finish. The increased efficiencies allowed the industry to compete effectively with foreign firms and to resist pressure from other materials like aluminum and plastics.

Current Conditions

Industry shipments increased in the late 1990s, growing from $23.6 billion in 1997 to $24.7 billion in 1999, before falling to $24.0 billion in 2000. The cost of materials increased from $12.67 billion in 1997 to $12.79 billion in 2000. Employment decreased steadily throughout the late 1990s, falling from 126,668 in 1997 to 118,695 in 1999. The total number of employees declined further in 2000 to 116,062. Payroll costs, however, increased from $5.6 billion in 1997 to $5.98 billion in 2000.

Industry Leaders

The largest stamping firms in the OEM portion of the industry remain the automotive manufacturers themselves, but those firms outsource about 25 percent of their new car stamping requirements to independent firms. In 1999, the largest of the independent stamping firms was Minneapolis-based Tower Automotive, Inc. Founded in 1955 and lead by CEO Dugald K. Campbell, Tower took the lead in the stamping industry for the first time in 1999. Tower employed almost 9,000 people in 1999 and generated approximately $1.2 billion in sales. Although Tower's headquarters are in Minneapolis, the company has a number of subsidiaries throughout the United States and is involved in various aspects of the automotive industry in addition to stamping.

The second largest independent metal stamper in 1999 was The Budd Company of Troy, Michigan, a subsidiary of Thyssen AG of Germany. Budd employed 10,000 workers to produce more than $1 billion in sales in 1999. Founded in 1912, the company pioneered the development of metal stampings throughout the early part of the century, racking up such firsts as the first four-door, all steel sedan body (Dodge), the first all-steel unitized body (Nash), stainless steel "streamliner" trains of the 1930s, the Navy's Conestoga RB-1 stainless steel cargo plane built during World War II, the prototype for the French Citroen, and the all-plastic-bodied 1954 Studebaker Coupe.

Metal stampings make up more than 50 percent of the company's sales, but it also manufactures fiberglass and plastic composite body panels, truck brake and wheel components, iron castings, and cold weather products like engine block heaters and interior car warmers. The German steel manufacturer and stamping firm, Thyssen AG, bought Budd Co. in 1978. The American firm had extended itself into many nonautomotive areas like aerospace and nuclear energy, reaching an employment high of 21,500, but it was loosing money. Thyssen propped up the company with influxes of capital, trimmed company operations, and limited operations to the automotive business to help it through the recession of the 1980s.


Traditionally, the large stamping plants, using large quantities of relatively unskilled workers, have operated with union labor. The main unions are the United Auto Workers (UAW) in the United States and the Canadian Automobile Aerospace and Agricultural Implement Workers (CAW) in Canada. However, many transplant operations have tried to use non-union labor throughout their operations including the on-site stamping plants.

With the shift to advanced automation at the newer plants, the traditional union stance of clearly defined job descriptions and classifications is giving way to more flexible arrangements like Ford's Modern Operating Agreement at its Wayne, Michigan, on-site stamping facility. Under that agreement, only one category of production worker exists. Each worker receives training on the entire manufacturing process to produce a teamwork approach. Displaced by sophisticated automation, the number of unskilled operators continues to decline. In their place, skilled tradesmen and craft-workers design and maintain the complicated production machinery and its robot servers.

Manufacturers and a growing number of labor leaders see automation as the key to preventing manufacturing facilities from relocating in Mexico with the advent of the North American Free Trade Agreement (NAFTA). Without the competitive edge of tireless automation, the lower wages accepted by Mexican workers would force manufacturers to relocate to stay competitive.

America and the World

The American stamping industry in the 1990s played catch-up with their European and Japanese counterparts. American plants typically wasted twice as much material, used more press operations, and ran presses at half the speed of foreign plants with production runs five times as long. Body panel sets costing $300 in a Japanese plant could cost $700 in its American counterpart. By building newer, more flexible plants and up-grading old presses where possible, American manufacturers began to slowly overcome their impediments.

Research and Technology

Modern stamping plants are using advanced technology to redefine themselves. Once the labor-intensive blacksmith shop of the auto industry, stamping now taps the skills and ingenuity of its workers to produce machines and computer monitoring systems to do repetitive work. At a fully automated plant like Ford's $600-million Wayne, Michigan, stamping plant, for example, human operators are used only to load raw steel into the plant and to remove the finished product at the end of the production line. Automatic guided vehicles follow roadways of wires embedded in the factory floor carrying barcoded metal to the correct storage area or the next press that needs that particular type of material. Transfer presses pass the metal down lines of six or eight similar machines to form complicated components. The completed parts exit the production area, and enter the transfer area where operators manually check them and rack them on a conveyor. Their next stop is the assembly facility.

Transfer presses need less production floor room, but often achieve only 25-30 percent operating efficiency because of their complexity. Simpler, easier to repair robot systems may become the technology of choice where the need for flexibility dominates. Robot systems appeal to small-batch producers like Budd Company. A "hard-tooled" automation system like a transfer press line may need expensive retooling every few years, but a "soft-tooled" robotic system can be upgraded by reprogramming and minor physical relocations.

The computer has also improved new die design and raw material usage, reducing both the production costs due to wastage and the design time needed for the evolution of a new car. Such programs can reduce the skilled man-hours needed for die face design by 50 percent, die face manufacture by 30 percent, and die tryout and corrective modification by 30 percent. Such improvements went a long way in reducing the traditional domestic car manufacturers'five-year new car design period, putting it in line with Japanese design periods of two or three years.

Further Reading

D&B Million Dollar Directory. Dun and Bradstreet, 1999.

United States Census Bureau. 1997 Annual Survey of Manufactures. Washington, D.C.: GPO, 1999. Available from .

United States Census Bureau. "Statistics for Industries and Industry Groups: 2000." Annual Survey of Manufacturers. February 2002. Available from .

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