The Washer (OEM Part No. 3128321959) is a spare part compatible with Boomer 281 and Boomer-282 underground drilling rigs. Manufactured from durable alloy steel, it is categorized as a mechanical component used in the fastening and load distribution system at the bolt connection position. This precision-made washer provides secure fastening support by distributing load pressure and improving connection stability between mechanical parts. Designed for demanding mining applications, it helps prevent assembly loosening, protects contact surfaces, and maintains reliable performance of drilling rig structures and mechanical assemblies under continuous vibration and heavy operating conditions.