NAS1351 socket head cap screws
Hex socket head cap screws with fine threads, UNRF-3A, in alloy steel, corrosion-resisting steel or A286.
NAS1351, machined to the standard.
NAS1351 is the National Aerospace Standard socket head cap screw with fine (UNRF-3A) threads. Its coarse-thread twin is NAS1352. The plain number is heat-treated alloy steel with a minimum tensile strength of 180,000 psi. A C after the number is corrosion-resisting steel and an N is A286 heat-resisting alloy. Heads are plain or drilled for safety wire.
- Machined from certified bar to the standard; no hot heading
- AS9100D and ISO 9001:2015 quality system; CAGE 8HH90
- DFARS-compliant material available on request
- No minimum quantity; prototype through production
- Material test reports and certificates of conformance with the order
Send the full part number with the dash number and code letters, the quantity, the required delivery and the documentation your purchase order calls for.
NAS1351 at a glance
| Detail | Specification |
|---|---|
| Standard | NAS1351, National Aerospace Standard (AIA) |
| Title | Screw, Cap, Socket Head, UNRF-3A |
| Material | Alloy steel; corrosion-resisting steel (C); A286 heat-resisting alloy (N) |
| Thread | Fine thread, UNRF-3A. #10-32 and 1/4-28 are the common sizes |
| Strength | Alloy steel: 180,000 psi minimum tensile. Corrosion-resisting steel: 80,000 psi minimum |
| Drive | Hexagon socket |
| Typical use | Aerospace structure, equipment and tooling where a compact internal-drive head is needed |
Part numbers covered: NAS1351 (alloy steel), NAS1351C (corrosion-resisting steel), NAS1351N (A286). Reference only; the current revision of the standard on your order governs.
Reading the part number.
| Element | Meaning |
|---|---|
| First dash number | Diameter. From #10 up it is in sixteenths of an inch: -3 is #10 (0.190 in.), -4 is 1/4 in., -5 is 5/16 in. |
| Second dash number | Length in sixteenths of an inch: -10 is 5/8 in. |
| C after NAS1351 | Corrosion-resisting steel |
| N after NAS1351 | A286 heat-resisting alloy |
| H before the length | Head drilled for safety wire |
| P at the end | Cadmium plated (alloy steel) |
How Cyclone makes them
Bar stock certified to the material specification is cut, turned and threaded to the standard’s dimensions, with drilled heads or shanks and head markings as the part number requires. Plating and locking elements are applied through partner facilities to the standard.
Lead time
Quoted on each order. Because the parts are machined from bar rather than scheduled through a heading run, lead time is set by machining capacity and material availability. Ask for the current lead time with your RFQ.
Quality
Cyclone’s published certifications include AS9100D, AS9120B, ISO 9001:2015, API Spec Q1, API 20E and API 20F. See quality and certifications.
Documentation
Material test reports and certificates of conformance ship with the order. Additional inspection reports and documentation are quoted to the purchase order.
Questions before you quote
What is the difference between NAS1351 and NAS1352?
The thread. NAS1351 is fine thread (UNRF-3A) and NAS1352 is coarse thread (UNRC-3A). The head, materials and code letters follow the same pattern.
What does NAS1351-3-10P mean?
A #10-32 alloy steel socket head cap screw, 5/8 in. long, cadmium plated.
Does Cyclone stock these?
No. Every part is made to order from certified bar, which is why there is no minimum quantity and why the quote confirms sizes and lead time.
Can you quote a cancelled or superseded number?
Yes. Many MS sheets were reissued as NASM or SAE AS standards with the part numbers unchanged. Send the number on your drawing and the quote names the current document.