Electronic assembly lines are built upon an ecosystem of diverse IoT devices and automated controllers that need to communicate with each other securely and efficiently to ensure effective production. However, the traditional authentication mechanisms are usually computationally expensive and not interoperable, meaning they are not fit for resource-constrained manufacturing devices. To address these challenges, this research proposes four blockchain-enabled lightweight authentication approaches for electronic assembly line IoT environments: 1. Blockchain-Assisted Hash-Chain Authentication (BAHCA), 2. Tokenized Lightweight Mutual Authentication (TLMA), 3. Consensus-Driven Lightweight Group Authentication (CLGA), and 4. Blockchain-Integrated Lightweight Zero-Knowledge Authentication (BLZKA). The process we follow in this study involves: (i) modelling the proposed schemes as an electronics assembly line IoT ecosystem, (ii) developing a toolkit for authentication workflows alongside the use case of blockchain enabled smart contracts, (iii) validating performance for different device density, communication load and assembly scenarios, and (iv) conducting a statistical comparison against four traditional schemes: Public Key Infrastructure (PKI)-based authentication, Pre-Shared Key (PSK)-based authentication, Extensible Authentication Protocol - Authentication and Key Agreement (EAP-AKA), and OAuth 2.0 token-based authentication. Results show that among the proposed schemes, TLMA provides more favourable performance in terms of latency reduction, energy consumption reduction, revocation efficiency improvement, and seamless interoperability among multi-vendor schemes.