McMasters Koss Company provides IATF 16949 and ISO 9001:2015 registered manufacturing and stocking distribution of O-Rings, Gaskets, Custom Molded Seals and Oil Seals.
Started by industry veterans, Robert (Bob) McMasters and Martin (Marty) Koss in the Detroit Metro area in 1977 to distribute O-Rings and seals to automotive manufacturers.
A Dedication to excellent quality and meeting on time requirements established McMasters Koss Company as a trusted supplier to large manufacturers in North America and worldwide.
McMasters Koss supplies O-Rings and seals to a wide variety of industries and major OEM manufacturers for automotive, truck, food and beverage, petroleum and other important industries.
McMasters Koss Company implemented a formal quality system in 2000 and has completed our ISO 9001:2015 Quality System certification in 2016.
We have completed our 2021 surveillance review and will have a new certificate valid until February 2023.
McMasters Koss Employees are generally long term with average tenure of over 15 years. Team members know how to quickly address your needs and accomplish objectives.
McMasters Koss is classified as a essential business in 2020 and have steps in place to continue supporting our customers during the worldwide pandemic.
Please click here to review our Covid-19 Safety Measures.
With over 20 years experience supporting engineering groups across North America and worldwide, we offer full support to your production facilities.
Please reach out to us with any Sealing Solution or logistical challenge you may encounter.
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