ALNmj MJ A286 Self-Locking Nuts (All-Metal Prevailing Torque)
ALNmj nuts are all-metal self-locking prevailing-torque nuts with MJ internal threads made from A286 stainless steel. They’re designed for demanding aerospace joints where repeatable locking performance is needed under vibration, thermal cycling and load reversals.
Where ALNmj is commonly used
ALNmj nuts are intended for fine-pitch MJ threads (MJ3 to MJ12) and are often selected for aerospace hardware such as engine accessories, actuators, high-temperature brackets and other assemblies where standard metric lock nuts are not suitable.
If the drawing specifies MJ internal threads and you need a robust, reusable locking method, ALNmj provides an all-metal prevailing-torque solution without a nylon insert.
What to expect
- All-metal prevailing torque to maintain clamp load under vibration
- Designed for repeatable installation/removal during inspection and maintenance
- Passivated finish for improved corrosion resistance
- Typical internal thread classes: 4H/5H or 4H/6H (per item)
ALNmj selection table (thread + key dimensions)
Use the table below to select the correct ALNmj nut by MJ thread size and key dimensions (A, B, E, H, K ref, S). Click the part number to open the detailed product page.
| Part Number | Thread | A | B | E | H | K ref | S |
|---|---|---|---|---|---|---|---|
| ALNMJ3x050A286SP | MJ3 × 0,5 — 4H6H | 6,0 | 4,9 | 4,4 | 3,0 | 0,5 | 4 |
| ALNMJ4x070A286SP | MJ4 × 0,7 — 4H6H | 8,0 | 6,5 | 5,5 | 4,0 | 0,6 | 5 |
| ALNMJ5x080A286SP | MJ5 × 0,8 — 4H6H | 9,2 | 8,0 | 6,7 | 5,0 | 0,6 | 6 |
| ALNMJ6x100A286SP | MJ6 × 1,0 — 4H5H | 10,5 | 9,4 | 7,8 | 5,4 | 0,9 | 7 |
| ALNMJ7x100A286SP | MJ7 × 1,0 — 4H5H | 12,6 | 11,3 | 8,9 | 6,2 | 1,0 | 8 |
| ALNMJ8x100A286SP | MJ8 × 1,0 — 4H5H | 13,6 | 12,3 | 11,1 | 7,2 | 1,1 | 10 |
| ALNMJ10x125A286SP | MJ10 × 1,25 — 4H5H | 16,6 | 15,2 | 13,3 | 9 | 1,3 | 12 |
| ALNMJ12x125A286SP | MJ12 × 1,25 — 4H5H | 19,8 | 18,2 | 15,5 | 10,8 | 2,0 | 14 |
Installation note (important)
Prevailing torque is not the same as tightening torque. Apply the installation torque specified for your joint (based on fastener size/grade and lubrication). Then confirm the nut’s prevailing-torque range meets your requirement (commonly referenced with ISO 2320 limits and test method).
FAQ
What is ALNmj used for?
ALNmj is selected for aerospace joints using MJ internal threads, especially where vibration, thermal cycling, or repeat maintenance access requires a reusable all-metal locking solution.
How do I know if I need MJ threads?
Use MJ when the engineering drawing/spec explicitly calls out the MJ thread form. Do not mix MJ with standard metric M unless the specification allows it. Always match MJ internal with MJ external threads.
Is ALNmj the same as ALNsbMJ?
They are related MJ self-locking nut families, but they are not interchangeable by default. Always select the series that matches the drawing requirements (design, dimensions, finish, standard callouts and acceptance criteria).
Need help choosing the right ALNmj part?
Share your MJ size, tolerance class, temperature requirements and finish preferences—we’ll help you confirm the best match.