Copper nuts are mainly classified into several types based on their structure, application, and processing method, including embedded round nuts (through-hole type A/blind-hole type B), knurled copper nuts, injection-molded copper nuts, self-locking copper nuts, and hexagonal copper nuts. Embedded nuts are the most commonly used for injection molding of plastic parts.
Embedded Round Nuts (GB/T 809 Standard) Specifically designed for pre-embedded plastic parts, conforming to the national standard GB/T 809, and divided into two basic types:
Type A (Through Hole): The thread minor diameter tolerance includes the centerline +0.1mm, facilitating punch insertion and preventing glue seepage into the threaded hole during injection molding.
Type B (Blind Hole): The bottom is closed, effectively isolating injection pressure and high-temperature molten glue, avoiding glue seepage problems, suitable for unilateral pressure scenarios.
Knurled Nuts: These nuts often feature straight-knurled surfaces and a central groove design to enhance the grip with plastic and prevent rotation. They are typically made of H59 brass, lead-free copper, or stainless steel.
Knurled Copper Nuts (Flower Nuts): The outer circumference is embossed with a grid pattern, herringbone pattern, chevron pattern, or diamond pattern to improve the bonding strength with plastic parts. Processing methods include knurling the raw material or simultaneously tapping and embossing during production. They are widely used in electronic product casings, automotive components, and medical equipment.
Injection Molded Copper Nuts: These specifically refer to copper nuts that are directly embedded into the plastic part during the injection molding process. High-temperature melting integrates the copper part with the plastic. Careful cooling control is necessary to prevent loosening or cracking at the joint due to temperature differences.
