Home / Military Fasteners / General Hardware & Testing Standards / MIL-N-25027/1
Military Specification Sheet (Superseded)

MIL-N-25027/1 — Self-Locking Nickel-Copper Nut Sheet (Legacy)

MIL-N-25027/1 was the detail sheet within the MIL-N-25027 self-locking nut family covering nickel-copper alloy (Monel) heavy hex nuts. It has been superseded by MIL-DTL-32258, whose nuts are dimensionally and functionally interchangeable with the legacy MIL-N-25027/1 part numbers by nominal diameter and temperature rating.

Status: Superseded — see MIL-DTL-32258 Type: Self-Locking Nut, Ni-Cu Alloy Parent Spec: MIL-N-25027 Direct Successor: MIL-DTL-32258

At a Glance

Full Title
Nut, Self-Locking, Nickel-Copper Alloy (Sheet 1 of MIL-N-25027)
Superseded By
MIL-DTL-32258 (28 Jun 2007)
Material
Nickel-Copper Alloy (Monel)
Diameter Range
1/4" – 2½"
Temp Ratings
250°F (base) / 450°F (V-suffix)
Parent Document
MIL-N-25027
Interchangeable With
MIL-DTL-32258 (same diameter/temp)
Current Guidance
Specify MIL-DTL-32258 for new designs

Overview

MIL-N-25027/1 was a detail specification sheet under the parent MIL-N-25027 self-locking nut family, describing the specific nickel-copper alloy (Monel) heavy hex nut variant — as opposed to the steel, aluminum, or copper-base alloy variants covered by other sheets or the base document. As with the rest of the MIL-N-25027 lineage, it was eventually superseded.

Its direct successor, MIL-DTL-32258 (issued June 28, 2007), states explicitly that nuts covered by MIL-N-25027/1 are interchangeable with equivalent MIL-DTL-32258 nuts of the same nominal diameter and temperature rating — meaning a legacy drawing calling out "M25027/1-08C" can be cross-referenced directly to "M32258-UCA08" under the current specification.

Legacy Part Number Cross-Reference

Select a nominal diameter to see the MIL-N-25027/1 to MIL-DTL-32258 cross-reference.

Legacy M25027/1-08C at 250°F cross-references to current M32258-UCA08 under MIL-DTL-32258.
!

MIL-N-25027/1 is superseded. Current and future procurement should reference MIL-DTL-32258, which covers the same nickel-copper alloy self-locking nut family with confirmed part-for-part interchangeability. This page is retained for legacy drawing cross-reference only.

MIL-N-25027/1 — Frequently Asked Questions

Can I directly substitute a MIL-DTL-32258 nut for a MIL-N-25027/1 callout?

Yes — the current specification explicitly states that nuts covered by MIL-N-25027/1 are interchangeable with MIL-DTL-32258 nuts of the equivalent nominal diameter and temperature rating.

What material did MIL-N-25027/1 nuts use?

Nickel-copper alloy, commercially known as Monel — chosen for its natural corrosion resistance in marine and shipboard environments alongside self-locking performance.

Need Monel Self-Locking Nuts to MIL-DTL-32258?

Ananka Fasteners manufactures current MIL-DTL-32258 self-locking nickel-copper alloy nuts with full material traceability.

Request a Quote