McMasters Koss Company Designs and sells O-Rings, Custom-Molded Rubber Shapes and Oil Seals to OEM’s in the automotive, heavy duty truck and industrial markets
Whether it is keeping your production line running, having the parts you need to complete a job or designing a new seal or molded shape to reduce leakage or wear, we are ready to serve.
All of our parts experience an incoming inspection as they enter our building and a second inspection before they are shipped to you.
We also offer 100% inspection for special circumstances.
McMasters Koss Company is ISO 9001:2015 Registered and offers APQP production and all levels of PPAP documents as well as NAFTA and material certifications.
We stock all sizes of Nitrile, Silicone, EPDM and Fluorocarbon (Viton) O-Rings with most popular metric sizes.
Quad Rings, Backup Rings and Oil Seals are supported on the most popular sizes.
JIT delivery is supported by maintaining reserve inventory for any OEM blanket orders.
McMasters Koss Bulk Parts Shipment 
McMasters Koss Commercial O-Ring Inventory Hallway 
Customer Specific O-Ring Inventory 
McMasters Koss Bulk Inventory Area 
McMasters Koss Bulk OEM Storage Facility 
McMasters Koss JIT Delivery System 
McMasters Koss Durometer Testing Center 
McMasters Koss Inspection Capabiltiies 
ASTM Specifications for Testing and Compliance 
McMasters Koss Global Shipments 
McMasters Koss Headquarters Complex 
McMasters Koss Oil Seal Environmental Test Chamber 
Custom Molded Rubber Seals 
Fluorocarbon O-Rings and Molded Seals 
Extruded Rubber Gasket 
Custom Molded Rubber Seals 
O-Rings 
McMasters Koss APQP Compliance 
Custom Molded Ball Seals 
Custom Molded Rubber Seals 
Oil Seals 
Custom Molded Rubber Seals 
Custom Molded Rubber Seals 
Extruded Rubber Seals