Metric key-lock inserts are fasteners used for thread repair or reinforcement, typically made of metal (such as stainless steel or brass) with knurled or keyed construction for a secure bond with a substrate (such as plastic or metal). These inserts are commonly used in applications requiring high torque or anti-loosening properties, such as 3D printed parts, automotive parts, or precision equipment. Key Features:
Thread Sizes: Common metric sizes include M2, M2.5, M3, M4, M5, M6, M8, M10, etc., with some products supporting M30 to meet different hole diameter requirements.
Material Types: The main body material is mostly 304 stainless steel (corrosion resistant, high strength) or brass (C3604, easy to machine, good conductivity). Inserts may use nylon inserts to achieve self-locking functionality.
Structural Design: Divided into keyed and heat-fitted types. Keyed types mechanically engage with the substrate via keyways, while heat-fitted types are pressed into plastic holes by heating.
Standards Compliance: Some products comply with international standards such as DIN 985 (non-metallic insert thin locknuts) or DIN 8140 (recoil inserts), ensuring interchangeability and reliability.
Applications: Suitable for thread reinforcement in soft materials such as plastics and aluminum alloys, and also used for repairing worn threads. Commonly used in 3D printing, automotive, and electronic equipment industries.
