Cord grips are used to pass a cord or cable into an enclosure, through a bulkhead or into a control device like a switch. They are used in industrial and commercial settings to control arc of bend or prevent a cable from being pulled out of a system. They also prevent cable damage and failure.
They seal an electrical connection from dirt, oil, moisture, dust and other contaminants and thus can be used in both dry and wet applications. Some common applications include motors, pumps, machine tools, processing and material handling.
Although standard products are available, many cord grip designs are custom. To specify a cord grip, consider the following selection criteria:
- Size — including outside diameter of the cable (to ensure a tight fit), whether single or multiple terminations are required, and size of knockout or threaded opening
- Thread type — NPT, Pg or ISO Metric
- Style and attachments — either straight, 45° or 90 degree style and whether wire mesh is required for attachment to prevent pull-out from the enclosure
- Materials of construction — usually driven by the application
Standard cord grip materials of construction include:
- Aluminum: The most common material of construction, aluminum offers excellent machinability, durability and performance.
- Nickel-Plated Aluminum: Provides a lightweight and lower cost alternative to higher-priced stainless steel. Ideal for applications requiring exceptional corrosion and wear resistance
- Nylon: Grips made from nylon are lightweight yet durable for use in marine, high-moisture and corrosive environments.
- Steel: Offering better tensile strength than aluminum, steel grips are usually zinc-chromium plated for enhanced rust-resistance.
- Valox: This material provides superior corrosion-resistance and is suitable for use in FDA washdown environments. However, it is expensive and offered in limited sizes.
- Stainless Steel: These designs feature exceptional tensile strength and durability in severely corrosive environments but can be costly.
- Diecast Zinc: Not commonly used, this is best for residential and commercial applications but not recommended for industrial.
Most cord grips come with the following standard options:
- Wire mesh
- Multiple hole bushings
- Tapered or straight threads
- Internal or external conduit threads
- VitonR, BunaN, Silicone or and Neoprene grommet materials
- Slit bushings
- Ability to accommodate either round or flat cable
Understanding all these options will keep you cord or cable safe and secure within its proper system orientation.