Click to enlarge Flames heat a die on the 35K hammer to bring the equipment up to forging temperature.

In an industrial area not far from the Los Angeles skyline is California Drop Forge, Inc. (CDF), a subsidiary of Ohio-based HBD Industries, Inc. Established in 1901, CDF boasts a long and rich history of producing precision, quality forged components. Early in its history, CDF forged metal parts and drilling-related components for the burgeoning oil industry. The company’s reputation as a supplier of high-quality precision parts soon spread to other industrial sectors such as the western railroad industry, which helped fuel the company’s growth.

California Drop Forge has been in the same Los Angeles location since its founding in 1901.

In the 1920s, CDF’s metal-forging expertise helped the company maintain its steady growth through the production of forged locomotive support parts. From its base as a metal-forging supplier to the railroad industry, CDF expanded into producing structure and support components for the growing U.S. aviation industry in the early 1930s. As commercial and military demands for strong, durable aviation parts steadily grew after the U.S. entered World War II, CDF established itself as a company that could produce quality closed-die forgings and machined components for aerospace, commercial aviation, military and defense applications.

With the passage of time, CDF continued to expand its markets. Today, the company produces metal forgings for use in power generation, marine and some specific medical applications, including orthopedic implants. It has established itself as a supplier of quality closed-die, net and near-net forgings, and fabricated components for these end-use applications as well as other custom applications.

The shaping of metal into precise forgings is an art form requiring a high level of craftsmanship and experience. CDF and its sister company, Precision Metal Parts, Inc. (to be profiled in the October issue of FORGE), claim more than 150 years of combined forging and metalworking experience. From their early beginnings in shaping iron and steel into forged parts to forging today’s exotic metals, both plants continue this tradition of craftsmanship in metal forging and fabrication. The plants’ combined capabilities and expertise at forging and machining components have led to an impressive customer list that includes companies like Airbus, Biomet, Boeing, Bombardier, General Electric, Hawker Beachcraft, Honeywell, Hamilton Sundstrand, Lockheed Martin, Pratt & Whitney, Raytheon, Rolls-Royce, Stryker, Zimmer and others.

Expertise in Precision Forgings

Click to enlarge The open-air 35K hammer forges parts up to 600 pounds.

With more than 110 years of metal-forging craftsmanship and manufacturing experience, CDF and its employees offer considerable expertise in forging lightweight, but extremely strong, metal and exotic alloys such as titanium, nickel-base, stainless steel, aluminum and various special-alloy steels. The company has earned a reputation around the world for its craftsmanship and the precision of its forged products, which include rotary engine parts, hubs, discs, aircraft structural parts, auxiliary power unit (APU) components and a range of landing-gear components.

CDF has played an important role as a supplier to both the commercial/private aviation business sectors as well as the U.S. military. The firm’s forged structural parts and components have been used on many well-known and long-serving military and commercial aircraft, including the McDonald Douglas/Boeing C-17 Globemaster; Lockheed C-130 Hercules; Apache helicopter; Airbus A320; Airbus A380; the Northrop B-2 bomber; Boeing’s 737, 747, 757, 777 and 787 commercial jets; the Tomahawk cruise missile; the C-5 Galaxy military transport jet; the Air Force’s F-14, F-15 Eagle, F-16, F-18 Hornet and F-22 Raptor fighter jets; and the latest U.S./NATO joint-strike fighter, the F-35.

Plant Capabilities

Click to enlarge A forklift operator removes heated parts from the furnace to move them to the final forging operation on the 35K hammer.

CDF operates six steam hammers ranging in size and mass from 2,500-35,000 pounds as well as two forge presses. This production equipment allows the company to manufacture a diverse array of parts and components varying in weight from less than 1 pound up to 600 pounds. The plant is a large manufacturing facility complete with its own mold/die shop, fluorescent die-penetrant testing capabilities, magnetic-particle inspection, layout inspection stations metallurgical and quality-control departments.

Additionally, company engineers offer customers product-design assistance using the latest in 3-D computer-modeling programs and techniques to help streamline the forging process, minimize material waste and deliver the most cost-efficient and strongest structural products possible.

CDF’s deformation and simulation computer-software programs enable the company to calibrate and accurately predict the reaction of the metal to be used in a finished forging by depicting grain flow, determining metal strain rates and calculating the required metal temperature at the finishing stage. Using these deformation/software programs, potential problems can be avoided and minor process adjustments can be made as the situation warrants. This flexibility ensures maximum efficiency in the design of critical or near-net forgings and establishes the proper flow of materials and mechanical properties throughout the entire forging process.

The company’s metallurgists work closely with their colleagues in engineering and quality control to develop and refine manufacturing processes so that performance-critical products made for aerospace/aviation applications meet or exceed the ever-changing safety and precision standards required. When forging critical components for use in jet engines, aircraft or any other purpose, CDF employees believe there is simply no margin for error or substitute for experience. CDF is an AS9100-accredited manufacturing company with quality certifications from Nadcap, and it is registered with the U.S. Department of Defense as a certified U.S. Military Parts Supplier.

Design, Simulation and Production Cycle

Heated bar stock is prepared for forging on a hydraulic press.

Through its decades of experience, the company has become proficient in overcoming customer design challenges by creating streamlined process solutions for complex production components. For example, it recently received fixed process approval on a new production forging for an APU propulsion system. The part had a unique configuration that required multiple simulations during the design stage. Using deformation technology, CDF was able to combine material data and variables such as transfer times and hammer energy to create simulations. These allowed the company to adjust their design and correct potential problems prior to running a tryout, saving time and cost. As a case in point, when the simulation showed that material was cooling too quickly, engineers redesigned the forging. Then engineering reran the simulation to demonstrate that the potential issue was remedied and that proper cooling rates would be attained.

Having completed a successful simulation, CDF performed a successful tryout. This particular part runs on the 12,000-pound hammer, which permits the achievement of ideal properties. After parts came off the hammer, they went through a round of processing. For this, CDF partners approved vendors for heat treating, sonic testing and production testing. CDF is also Nadcap-approved to perform nondestructive testing on this part and many others.

This specific component is produced out of 6-2-4-6 G2 Titanium, one of the many metals that CDF specializes in forging. The material type and part configuration meant that the final forging had a unique microstructure that required additional testing. Tests on the part included microstructure, grain flow and fatigue testing. Substantiation results were then submitted to the customer for approval. By maintaining close and open communications between CDF’s technical team and its customer, the company was able to successfully qualify this part and launch it into production.

Moving Forward

An NDT inspector sprays parts during fluorescent-penetrant inspection.

The steady growth of the aerospace/aviation business sector and industry predictions for expanding future business has shown CDF that it must develop even closer working relationships and pay increased attention to its aerospace customers. CDF’s employees can use their skills and expertise in metal forging to help customers avoid costly problems in planning, engineering and designing aerospace/aviation structural parts and components. The company’s extensive metal-forging expertise will enable it and its aerospace customers to develop and forge newer, lighter and even stronger aerospace component parts to meet future industry requirements.

For further information on California Drop Forge readers may call 323-221-1134; fax 323-222-6768; email sales@californiadrop.com; or visit www.caldrop.com. All photos by Ian Grant at Ian Grant Photography, LLC, ian@distinctphoto.com.

SIDEBAR: CDF's Role in the Miracle on the Hudson

During the Hudson River emergency water landing of US Airways Flight #1549 in January 2009, California Drop Forge aviation components performed a vital, but hidden role in helping save the lives of the 155 passengers and crew aboard the plane. Captain Chesley Sullenberger, the now-famous pilot of Flight #1549, engaged and was able to use the plane’s auxiliary power unit (APU) to maintain flight control over the aircraft even though both main jet engines had ceased to function. Using the power generated by the small APU, Captain Sullenberger was provided with enough critical electrical and hydraulic function to give him sufficient flight control to safely glide Flight #1549 into a soft-water landing in the Hudson River. The APU in this plane is manufactured by Honeywell International, and two of its most important metal components are forged by CDF.