NAS6220 bolts
NAS6220 is the 1-1/4-12 UNJF-3A size of the NAS6203–NAS6220 close-tolerance hex head bolt: alloy steel, short thread, 160 ksi. Machined to order in Houston.
NAS6220, machined to the standard.
NAS6220 is one diameter in the NAS6203–NAS6220 series. The last two digits give the diameter in sixteenths of an inch, so NAS6220 is the 1-1/4 in. bolt, threaded 1-1/4-12 UNJF-3A. The dash number that follows gives the grip length in sixteenths: NAS6220-10 has a 5/8 in. grip.
NAS6203 through NAS6220 is the current alloy steel close-tolerance hex head bolt with a short thread and reduced major thread diameter, heat treated to 160 ksi minimum tensile. It replaced the NAS1103 series and the NAS464 shear bolt, both inactive for design. Material is 4140, 4340 or 8740 alloy steel, cadmium plated; self-locking and nonlocking versions are on the same sheet. The last two digits give the diameter in sixteenths and the dash number the grip. AIA issued revision 12 in 2024.
- 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.
NAS6220 at a glance
| Detail | Specification |
|---|---|
| Part number | NAS6220 |
| Thread | 1-1/4-12 UNJF-3A |
| Nominal diameter | 1.250 in. |
| Standard | NAS6203 thru NAS6220 (active, 2024 revision) |
| Material | 4140, 4340 or 8740 alloy steel; cadmium plated (default) or chromium plated (C) |
| Strength | 160,000 psi minimum tensile |
| Head | Low-profile hex head; drilled shank (D), drilled head (H) or both (DH) |
| Dash number | Grip length in sixteenths of an inch |
Reference only; the current revision of the standard on your order governs.
Reading a NAS6220 part number.
A complete callout is the base number, a dash number for grip, and code letters for options: NAS6220-10 is the plain bolt with a 5/8 in. grip, and NAS6220-10D is the same bolt with a drilled shank.
| Element | Meaning |
|---|---|
| NAS6220 | 1-1/4 in. diameter, 1-1/4-12 UNJF-3A thread |
| Dash number | Grip in 1/16 in. increments |
| C | Chromium plated |
| L | Self-locking element |
| D / H / DH | Drilled shank / drilled head / both |
NAS6220 dash numbers and grip lengths
The dash number is the grip, the unthreaded length under the head, in sixteenths of an inch. The standard lists the dash numbers available for each diameter; longer grips continue the same rule.
| Dash | Grip | Dash | Grip |
|---|---|---|---|
| -1 | 1/16 (0.0625) in. | -25 | 1-9/16 (1.5625) in. |
| -2 | 1/8 (0.125) in. | -26 | 1-5/8 (1.625) in. |
| -3 | 3/16 (0.1875) in. | -27 | 1-11/16 (1.6875) in. |
| -4 | 1/4 (0.25) in. | -28 | 1-3/4 (1.75) in. |
| -5 | 5/16 (0.3125) in. | -29 | 1-13/16 (1.8125) in. |
| -6 | 3/8 (0.375) in. | -30 | 1-7/8 (1.875) in. |
| -7 | 7/16 (0.4375) in. | -31 | 1-15/16 (1.9375) in. |
| -8 | 1/2 (0.5) in. | -32 | 2 in. |
| -9 | 9/16 (0.5625) in. | -33 | 2-1/16 (2.0625) in. |
| -10 | 5/8 (0.625) in. | -34 | 2-1/8 (2.125) in. |
| -11 | 11/16 (0.6875) in. | -35 | 2-3/16 (2.1875) in. |
| -12 | 3/4 (0.75) in. | -36 | 2-1/4 (2.25) in. |
| -13 | 13/16 (0.8125) in. | -37 | 2-5/16 (2.3125) in. |
| -14 | 7/8 (0.875) in. | -38 | 2-3/8 (2.375) in. |
| -15 | 15/16 (0.9375) in. | -39 | 2-7/16 (2.4375) in. |
| -16 | 1 in. | -40 | 2-1/2 (2.5) in. |
| -17 | 1-1/16 (1.0625) in. | -41 | 2-9/16 (2.5625) in. |
| -18 | 1-1/8 (1.125) in. | -42 | 2-5/8 (2.625) in. |
| -19 | 1-3/16 (1.1875) in. | -43 | 2-11/16 (2.6875) in. |
| -20 | 1-1/4 (1.25) in. | -44 | 2-3/4 (2.75) in. |
| -21 | 1-5/16 (1.3125) in. | -45 | 2-13/16 (2.8125) in. |
| -22 | 1-3/8 (1.375) in. | -46 | 2-7/8 (2.875) in. |
| -23 | 1-7/16 (1.4375) in. | -47 | 2-15/16 (2.9375) in. |
| -24 | 1-1/2 (1.5) in. | -48 | 3 in. |
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 thread is NAS6220?
1-1/4-12 UNJF-3A. The bolt has a 1.250 in. nominal diameter.
What does the dash number on NAS6220 mean?
The grip length in sixteenths of an inch. NAS6220-8 has a 1/2 in. grip and NAS6220-16 has a 1 in. grip.
What material is NAS6220?
4140, 4340 or 8740 alloy steel; cadmium plated (default) or chromium plated (C). Minimum tensile strength is 160,000 psi.
Does Cyclone stock NAS6220?
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.
Is DFARS-compliant material available?
Yes, on request. This refers to material sourcing; state the DFARS clause on your purchase order.