Case Study – Railroad Car Motor Suspension Bracket 

Investment casted motor suspension bracket surpasses quality expectations for Pennsylvania railroad.

At Waltek, our customers in a wide range of industries rely on our commitment to high quality investment casting. In this project a Pennsylvania railroad company required a casted suspension bracket strong enough to keep the traction motor of a railroad car stable. Traction motors are an electric motor which provides the primary rotational torque used to convert linear motion. They are often used in electric locomotives or any vehicle, elevator, and conveyor with electrical transmission systems. Backed by over 30 years of high quality investment casting experience, our team was able to plan, design, and produce the part in less than 8 weeks according to the customer’s specifications.

Our company has a broad range of experience in investment casting for the industrial marketplace. We offer a service-oriented methodology that’s flexible; working with our customers during the entire production process. To meet the stringent quality control requirements necessary for railroad parts, our team worked with customer specifications to design a suspension bracket capable of resisting vibration and stress forces associated with railroad motors. After working with the customer’s specifications and CAD design, a master wax impression mold was created. Hot liquid paste was injected into the die, hardening and forming a pattern of the part. The wax pattern is dipped in ceramic slurry, covered with sand stucco, and allowed to dry. Once hardened, the part is placed in our autoclave which removes or burns out all traces of the wax, leaving a ceramic mold. The mold was placed in our pre-heat oven and filled with molten alloy 4320 steel, creating the actual metal casted part. Our team post processed the part with a series of cutoff, deburring, heat treatment, and painting processes. To ensure accurate dimensioning, the final 29 lb. part underwent a series of tests using in-house measuring equipment to ensure proper metal content, mechanical strength, and structural integrity. The suspension bracket ultimately measured 250 mm long x 102 mm wide x 192 mm tall.

Our Investment casting process provides greater design flexibility, higher tolerances, and better part reliability when compared to traditional sand casting. The suspension bracket surpassed our customer’s expectations for quality and dimensional accuracy. Depending on the complexity of your design, our team can rapid prototype and produce a cast in as little as 3 weeks. If you’re interested in learning more about this project or the processes involved to complete it, please refer to the table below or contact us.

Product Description: The part is a suspension bracket that holds the traction motor used in railroad cars.

Capabilities Applied/Processes: Primary: Investment Casting
Secondary: Heat Treat, Machining and Painting

Equipment Used to Manufacture Part: Wax Mold
Melting Furnace
Pre-heat Oven
Cut-Off and Deburring Equipment
Heat Treat Oven
CNC and a Painting Line

Expertise: Investment Casting

Overall Part Length: 250 mm

Overall Part Width: 102 mm

Overall Part Height: 192 mm

Tolerance (±): .075 in

Material Used: Alloy 4320 Steel

Finish: Painted

In Process Testing/Inspection Performed: Spectrometer
Viscous Equipment
Testing for Tensile
Yield Strength
Reduction of Area
Metal Content

Industry Focus: Rail Road

Weight: 29 lb

Delivery/Turnaround Time: 8 weeks

Delivery Location: Pennsylvania

Standards Met: 2D CAD Drawing
Customer Specifications

Product Name: Suspension Bracket