Skid Steer Snow Plows | Skid Steer Solutions Browse our wide selection of Skid Steer Snow Plows! We offer models with fixed or manual angles, as well as hydraulically operated snow plows available in multiple models ensuring they will work great on your machineons include Blue Diamond, Haugen, CID, and more. Cat 299d problems Cat 299d problems O-Ring Durometer Chart The hardness of rubber o-ring compounds are measured by the Shore A durometer; the higher the durometer, the harder the compound. 70-durometer hardness should be used whenever possible as it offers the best combination of properties for most o-ring applications. SAE Flange O-Rings Our SAE 4 bolt Flange O-rings are offered in Buna-N / Nitrile (NBR) 90 or Viton / FKM 90. Ideal for use in forming a seal between flanges, our SAE Flange O-rings are sold as individual parts or as o-ring kits.