KH-A42002-03A Wire-to-Board Connector: A Reliable Solution for Stable Connections with 4.2mm Pitch and 1×3P Straight Pins

In electronic equipment design, connectors serve as the “capillaries” that enable signal and power transmission between cables and PCBs. Although they may seem like small, insignificant components, they directly affect the long-term operational stability of an entire device.

Kinghelm introduces the KH-A42002-03A, a classic single-row, straight-pin header from the 5557 series. Featuring a standard 4.2mm pitch and a 1×3P through-hole configuration, this connector combines reliable current-carrying capacity, broad compatibility, and convenient assembly. It provides a proven wire-to-board connection solution for industrial control, power supplies, lighting, home appliances, and other applications.

Kinghelm KH-A42002-03A Product Image

1. Precision Structural Design for Compatibility with the Established 5557 Series

The KH-A42002-03A is a through-hole, straight-pin wire-to-board header featuring a standard 4.2mm pitch and a single-row, 3-pin configuration, with a board-mounted height of 12.8mm.

Its dimensions are precisely controlled, with strict tolerances for pin positioning. It is fully compatible with matching housings and terminals in the same 5557 series, allowing engineers to integrate it into existing designs without having to modify the mechanical structure. This provides significant compatibility advantages during component selection and product development.

The product is supplied in bag packaging and supports two mainstream production methods. It can be used on automated through-hole assembly lines for large-scale manufacturing, while also being suitable for manual assembly and debugging during the R&D and prototyping stages.

The same product series covers multiple pin-count options, including 02A, 03A, 04A, 05A, and 06A. Designers can standardize connector components across an entire product platform, simplify the bill of materials (BOM), and reduce inventory and procurement management costs.

2. Solid Electrical Performance for Low- and Medium-Power Applications

Electrical performance is one of the most important factors in connector reliability. The KH-A42002-03A features a rated current of 7A and a rated voltage of 600V AC/DC, making it suitable for low- and medium-power supply connections as well as control signal transmission.

The conductive contacts are made of brass with a tin-plated finish, providing excellent electrical conductivity. Maximum contact resistance is controlled within 20mΩ, helping minimize heat generation and abnormal voltage drops during long-term operation.

Its insulation performance is equally reliable, with a minimum insulation resistance of 1000MΩ and a dielectric withstand voltage of 1500V AC for one minute. These characteristics help reduce the risk of leakage and electrical breakdown under high-voltage conditions.

With an operating temperature range of -25°C to +85°C, the connector can withstand temperature variations caused by internal equipment heat and low outdoor temperatures, maintaining stable connections even in environments subject to significant temperature fluctuations.

3. Flame-Retardant, Durable Materials and Secure Mechanical Locking

The insulating housing is manufactured from PA66 nylon and meets the UL94 V-2 flame-retardant rating. It offers good aging resistance and dimensional stability, helping prevent softening or deformation at elevated temperatures and reducing potential short-circuit risks caused by plastic deformation.

The straight pins feature an integrated design, ensuring that the terminals remain straight and properly aligned. This allows smooth insertion into PCB holes during through-hole soldering, reducing the likelihood of bent or misaligned pins and helping lower PCB assembly defect rates.

The housing also features an integrated locking structure. When mated with a compatible connector housing, it forms a secure locking connection. Even in equipment exposed to continuous vibration or movement, the wire harness is less likely to loosen or disconnect. This mechanical retention helps address common problems such as wire harness detachment and signal interruptions in electronic devices during long-term operation.

4. Versatile Applications Across Industrial Control, Home Appliances, and Lighting

Thanks to its broad compatibility, the KH-A42002-03A can be used in a wide range of mainstream industries.

In industrial control applications, it can provide power and signal connections for sensors, small motor drives, and PLC control boards.

In consumer electronics and home appliances, typical applications include water heaters, small appliance control boards, computer case fans, and high-power LED driver modules.

It is also suitable for security equipment, access control power supplies, and low-voltage lighting modules.

In many devices, the connector handles both power supply and signal transmission. Its standardized specifications make it a practical alternative to comparable imported connectors, helping manufacturers optimize material costs without compromising required performance while reducing dependence on overseas component supply chains and minimizing delivery uncertainties.

Kinghelm KH-A42002-03A Datasheet

5. Reliable Supply for a Stable Electronic Connection Chain

As the electronics industry continues to evolve toward lightweight and modular designs, many engineers are looking for connectors that offer sufficient current-carrying capacity without the high tooling costs and long development cycles associated with customized components.

Standardized 4.2mm-pitch headers such as the KH-A42002-03A are well suited to these requirements.

Kinghelm leverages its established supply chain and quality control system to implement comprehensive quality management throughout the manufacturing process, from incoming raw material inspection and injection molding to terminal electroplating and finished-product testing. These procedures help ensure consistent product specifications across mass-production batches and support reliable, long-term supply.

Overall, the KH-A42002-03A is not designed to pursue extreme miniaturization. Instead, it is a practical, high-performance basic component that strikes a balance between performance, cost, and versatility.

Its mature 4.2mm pitch, 7A current-carrying capacity, flame-retardant and heat-resistant housing, stable electrical specifications, and comprehensive product series make it an ideal choice for power and signal connections in a wide range of electronic devices.

About Kinghelm

According to Mr. Song Shiqiang, Kinghelm (www.kinghelm.net) was established in 2007 in Huaqiangbei, Shenzhen, and has since focused on the development and manufacturing of BeiDou/GPS antennas, various connectors, electronic interconnect components, RF components, and customized special-purpose components.

With its modern manufacturing base in Luzhai, Guangxi, and intelligent, flexible production lines, Kinghelm has established comprehensive, one-stop development capabilities covering product design, mold development, performance testing, and mass production. These capabilities enable the company to deliver products in large volumes with high consistency and short lead times.

Among the popular Kinghelm KH-series products available in Huaqiangbei are KH-6X6X6H-STM, KH-IPEX-K501-29, KH-6X6X5H-STM, KH-6X6X5H-Z2J, KH-3216-H0209, KH-VH-PT3.96, and KH-SMA-P-8029, along with many other models.

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