| Feature | NAS1057 Spacer | Standard Washer (NAS1149) | | :--- | :--- | :--- | | | To create a specific gap/length. | To distribute bearing load. | | Length | Significant length relative to diameter. | Very thin (minimal thickness). | | Tolerance | Length tolerance is tightly controlled. | Thickness tolerance is less critical. | | Load Application | Designed for compression/standoff. | Designed to prevent pull-through. |
Standardized dimensions and tolerances allow for consistent use across different manufacturers and aerospace platforms.
| Standard | Description | Material | Finish | Use Case | |----------|-------------|----------|--------|-----------| | | Hexagonal standoff / spacer | 303/304 SS, Al 2024, CRES | Passivated, anodized, cad plate | General spacing, electronic chassis, airframe | | NAS1066 | Thin wall bushing (precision ID) | 4130 steel, 17-4PH | Cadmium plate, dry film lube | Bolt hole alignment, wear reduction | | NAS1067 | Heavy wall bushing | Same as NAS1066 | Same | High-load bearing surfaces | | MS21248 | Spacer, sleeve (general) | Steel, CRES | Cad plate | Non-structural spacing |
Many variants are DFARS (Defense Federal Acquisition Regulation Supplement) compliant and meet RoHS/REACH standards for hazardous materials. Material Options and Temperature Limits