Aerospace nuts are almost always self-locking, so they cannot vibrate loose. Nylon-insert nuts (AN365, MS21044) are used up to about 120 °C; all-metal locking nuts (MS21042, MS21045, MS21043) take higher temperatures and engine use.
Castellated nuts (AN310, AN320) are locked with a cotter pin through a drilled bolt. NAS1149 washers replaced AN960 and are the standard flat washer.
Common AN, MS and NAS sizes in alloy steel and stainless steel are usually available ex-stock in India. Superalloy, titanium and special NAS parts are imported for you from AS9120-certified distributors, with certificate of conformity, mill test reports and full lot traceability. Ask us for current stock and lead time.
Specifications
| All-metal locking | MS21042 (reduced hex), MS21045, MS21043 (CRES), NAS1291 (low height) |
|---|---|
| Nylon insert locking | AN365 / MS21044 (full height), MS21083 (thin) |
| Castellated | AN310 (standard), AN320 (shear) |
| Plain nuts | AN315, AN316 jam |
| Washers | NAS1149 / AN960 flat, AN970 large OD, MS35338 split lock |
| Materials | Alloy steel (cad plated), CRES, A286, aluminium |
| Threads | UNF / UNC #4 to 1" |
Common aerospace nuts
| Nut | Type | Typical use |
|---|---|---|
| MS21042 | Reduced hex, all-metal self-locking | Engines, tight spaces, high temperature |
| MS21044 / AN365 | Hex, nylon insert self-locking | General airframe, up to ~120 °C |
| MS21045 | Hex, all-metal self-locking | Higher temperature airframe joints |
| AN310 | Castellated, cotter-pin locked | Rotating joints, controls |
| AN320 | Castellated shear nut | Shear-loaded bolts only |
| NAS1291 | Low-height all-metal locking | Weight-critical joints |
Key features
- Self-locking designs
- Matched to AN / NAS bolts
- High-temperature options
Applications
Need a size, grade or finish not listed? We also make special and non-standard parts to drawing. Ask us →
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Aerospace Fasteners: OverviewAN, MS and NAS fasteners in alloy steel, CRES, A286, Inconel and titanium, supplied in India with full traceability.View details →
Aerospace Bolts & Screws (AN, NAS, MS)AN3–AN20 hex bolts, NAS close-tolerance bolts, NAS socket cap screws and MS countersunk screws.View details →
Aerospace Rivets, Pins & CollarsMS20470 / MS20426 solid rivets, blind structural rivets, Hi-Lok-type pins and collars, clevis and cotter pins.View details →
High-Temperature Alloy Fasteners (A286, Inconel)A286, Inconel 718, Waspaloy, MP35N and 17-4PH bolts, nuts and studs for heat and corrosion.View details →