MIL-N-25027 — Self-Locking Nut, 250°F / 450°F / 800°F (Legacy)
MIL-N-25027 was the original military specification for self-locking nuts rated to 250°F, 450°F, or 800°F depending on base material. Through Revision G, it was superseded by MIL-DTL-25027, which was itself later superseded by NASM25027 — the specification's active governing document today.
At a Glance
Overview
MIL-N-25027 was the earliest military specification governing self-locking nuts for use at 250°F, 450°F, and 800°F, defining acceptable base materials for each temperature class — copper-base and aluminum alloys limited to 250°F, corrosion resistant steel capable of reaching 800°F, and non-corrosion-resistant steel limited to 250°F or 450°F.
The specification went through revisions lettered A through G before being converted to the "DTL" detail-specification format as MIL-DTL-25027. That document was in turn superseded on December 14, 1999 by NASM25027, transferring maintenance to the Aerospace Industries Association's NAS/Military document family — where it remains today.
A companion sheet specification, MIL-N-25027/1, covered a specific nickel-copper alloy (Monel) plate-nut variant and has since been superseded by MIL-DTL-32258.
Full Specification Lineage
| Document | Status |
|---|---|
| MIL-N-25027 (through Rev. G) | Superseded by MIL-DTL-25027 |
| MIL-DTL-25027 (Rev. H, 1997) | Superseded by NASM25027 |
| NASM25027 (1999–present) | Active, current governing document |
| MIL-N-25027/1 (Monel plate nut sheet) | Superseded by MIL-DTL-32258 |
MIL-N-25027 is superseded. Current and future procurement should reference NASM25027. If your drawing specifically references the Monel plate-nut sheet MIL-N-25027/1, the applicable current document is MIL-DTL-32258.
MIL-N-25027 — Frequently Asked Questions
What's the relationship between MIL-N-25027, MIL-DTL-25027, and NASM25027?
They form a single lineage: MIL-N-25027 was the original specification, MIL-DTL-25027 was its "DTL"-format successor, and NASM25027 is the current active document after maintenance transferred to the Aerospace Industries Association in 1999.
What was MIL-N-25027/1?
A companion sheet specification within the MIL-N-25027 family, covering a nickel-copper alloy (Monel) plate-nut variant. It has since been superseded by MIL-DTL-32258.
Need Self-Locking Nuts to NASM25027?
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