Maximum Security Range Padlocks Security Rating: 7-10 High to maximum security for all applications including commercial and industrial. Lockwood Maximum Security 270 Series Steel Case PadlocksPadlocks Physical Security (SP) grade 9. Lockwood Maximum Security 290 Series Steel Case Monoblock PadlockPadlocks Physical Security (SP) grade 10. Lockwood Maximum Security 301 Series Steel Padlock Padlocks Physical Security (SP) grade 8. Lockwood Maximum Security 356 Series PadlocksPadlocks Physical Security (SP) grade 8.