

The Graco 16U977 Jam Nut is an OEM hardware piece used to securely lock pump-lower components in high-pressure Graco fireproofing and industrial pump systems.
The Graco 16U977 Jam Nut is a genuine OEM hardware component used to secure and lock critical pump-lower parts in high-pressure industrial spraying and pumping equipment. It maintains alignment, prevents loosening under pressure, and ensures long-term reliability of the pump assembly.
| Specification | Details |
|---|---|
| Part Number | 16U977 |
| Category | Jam Nut / Hardware Component |
| Compatibility | Pump-Lower Assemblies in Fireproofing & Heavy-Duty Graco Systems |
| Function | Locks and secures pump components under high pressure |