The meaning of the Acronym HRR is...

HRR is

• Rockwell R Hardness Number

More Meanings For HRR:

• Rockwell R Hardness Number
• Hot Rod Reissue
• History Records Register
• Her Royal Roommatedness
• Heart Rate Reserve
• Herrera, Colombia

HRR is also in:

• Airport Codes
• Physiology
• Plastics
• Unfiled