Circular Connector Rectangular Connector Industrial Connector Optoelectronic Connector Hangzhou Yunshi Technology Co., Ltd.
Circular electrical connectors come in many varieties – they may be circular or rectangular in cross‑section, but their manufacturing processes are broadly similar. In general, the production of these connectors can be broken down into the following four stages:
The process begins with selecting the right materials, based on the customer's contract specifications. This step is critical: if the material choice is wrong, everything that follows is wasted effort.
For the shell, the selection depends on the intended operating environment – including requirements for shielding, sealing, and environmental compliance (e.g., RoHS). Common shell materials include aluminium, copper, stainless steel, and Kovar alloy. The insulator is typically made from PTFE (polytetrafluoroethylene), and its temperature rating and vibration resistance must be taken into account. In addition, the mechanical structure and the physical dimensions of the materials must be considered.
After the contact pins are stamped and the shells are machined, the parts are sent for plating. In this stage, the electrical contact surfaces are coated with various metallic finishes – options include silver, gold, anodised colour finishes, military green, chromium, nickel, and stainless steel passivation, each corresponding to different technical requirements and processing methods.
However, for many machine vision system suppliers, plating remains a "blind spot" when it comes to quality inspection. Connector manufacturers would like inspection systems to detect inconsistencies on plated contact surfaces, such as fine scratches and pinholes. While these defects are relatively easy to spot on flat products (e.g., aluminium can lids), the irregular, angled surfaces of most connectors make it difficult for vision systems to capture images with sufficient detail to identify such minute flaws. This is an area where the plating industry still seeks improvement.
The insulator of a circular electrical connector is typically produced by injecting molten plastic into a metal mould, followed by rapid cooling to solidify the part.
Common defects at this stage include partially or completely blocked insulator cavities – these holes must remain clean and unobstructed to allow proper mating with the contact pins during final assembly. Burrs may also form around the edges. Fortunately, the post‑moulding quality inspection is relatively straightforward: vision systems can be used, and if needed, manual re‑inspection is also feasible. Operators can remove burrs, hold the parts up to a light to check for blockages, and even pass a pin through each hole to ensure it is clear, thereby guaranteeing quality.
The final stage is product assembly. After assembly, insertion‑withdrawal tests are performed. There are two approaches: individual mating (engaging one pin at a time) or gang mating (inserting multiple pins into the socket housing simultaneously). Regardless of the method used, manufacturers must verify that all pins are present and correctly positioned.
Once the pin‑to‑socket engagement has been confirmed, the overall fit between plug and receptacle is checked – ensuring smooth operation and that the locating rivets function as intended. Finally, the finished connectors are visually inspected for scratches, uneven screw lengths, or any other basic defects, before they are sent for final quality acceptance.
