AN3 through AN20 aircraft bolts
The general-purpose airframe hex head bolt, #10-32 through 1-1/4-12 UNF-3A, in alloy steel, corrosion-resistant steel or aluminum alloy.
AN3–AN20, machined to the standard.
AN3 through AN20 is the standard sheet for the aircraft machine bolt: a hex head with washer face, fine thread, and a drilled shank for a cotter pin as the default configuration. The AN number gives the diameter (AN3 is #10-32, AN20 is 1-1/4-12) and the dash number gives the length. The sheet was cancelled in 1999 and is published today as NASM3 thru NASM20; part numbers are unchanged and the AN callout is still what most drawings and purchase orders use.
- 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.
AN3–AN20 at a glance
| Detail | Specification |
|---|---|
| Standard | AN3 thru AN20, now NASM3 thru NASM20 (active) |
| Title | Bolt, Machine, Aircraft |
| Material | Alloy steel, cadmium plated (default); C = corrosion-resistant steel; DD = aluminum alloy |
| Thread | UNF-3A, #10-32 through 1-1/4-12 |
| Head | Hex head with washer face; head and shank drilled as coded |
| Strength | 125,000 psi minimum tensile for steel bolts, per distributor and DLA data |
| Typical use | General airframe structural bolt in tension or shear |
Part numbers covered: AN3, AN4, AN5, AN6, AN7, AN8, AN9, AN10, AN12, AN14, AN16, AN18, AN20. Reference only; the current revision of the standard on your order governs.
Reading the part number.
| Element | Meaning |
|---|---|
| AN3 … AN20 | Diameter: AN3 = #10-32, AN4 = 1/4-28, AN5 = 5/16-24, AN6 = 3/8-24, AN7 = 7/16-20, AN8 = 1/2-20, AN10 = 5/8-18, AN12 = 3/4-16, AN14 = 7/8-14, AN16 = 1-12, AN18 = 1-1/8-12, AN20 = 1-1/4-12 |
| Dash number | Length, from the sheet table |
| C before the dash | Corrosion-resistant steel |
| DD before the dash | Aluminum alloy |
| A after the dash | Undrilled shank |
| H before the dash | Drilled head and shank; with A after the dash, drilled head only |
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
Is an AN bolt the same as a NASM bolt?
Yes. The AN sheet was cancelled in 1999 and reissued as NASM3 thru NASM20 with the part numbers unchanged. Cyclone quotes either callout.
Which material does Cyclone quote by default?
The material code on your part number. Steel bolts are quoted in certified alloy steel with cadmium plating through a partner facility; C-coded bolts in corrosion-resistant steel.
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.