The Washer (OEM Part No. 3128311807) is a mechanical spare component compatible with Boltec S10M, Boltec S,Boltec 235 , Boltec-MC, and Boomer-MD underground drilling rigs. Manufactured from durable alloy steel, it is designed for the fastening assembly mounting position. The washer provides load distribution and secure fastening between connected components, helping maintain proper assembly stability and alignment. Its robust construction ensures reliable performance, accurate fitting, and extended service life under demanding underground mining conditions. This OEM replacement washer supports the durability and reliability of mechanical fastening systems.