generic-NAS, hex-drive blind bolt
Jo-Bolt
Jo-Bolt (NAS1669/NAS1670): three-piece threaded blind bolt; Visu-Lok II is Monogram's listed replacement.
- Shear 50-85 ksi
- Access Blind (one-sided)
- Diameters 5/32 to 3/8"
- Materials Alloy steel, A286 CRES +1
- Lead-time risk Medium
Blind (one-sided), threaded blind bolt: “During installation, the nut is held stationary while the core bolt is rotated by the installation tooling.” (FAA-H-8083-31B (AMT Handbook, Airframe), p.4-54, Drive Nut-Type of Blind Bolt)
- Shear
- 50-85 ksi
- Blind bulb
- standard
- Install
- One-side install
- Diameters
- 5/32, 3/16, 1/4, 5/16, 3/8"
- Lead-time risk (SpecLok assessment)
- Medium
Typical applications
- ·"used for high strength applications in metals and composites when there is no access to the blind side" (FAA-H-8083-31B p.4-54, drive nut blind bolts)
Strengths
- +Drive nut concept: "composed of a nut, sleeve, and a draw bolt" (FAA-H-8083-31B p.4-54)
- +Flush and protruding heads in alloy steel, A-286 and aluminum, plus oversizes (Visu-Lok II brochure p.6 cross-reference)
Trade-offs
- −Values shown are for the Monogram NAS-replacement parts; NAS1669/1670 sheets are not public
- −No public install, inspection or removal procedure specific to Jo-Bolt was found
Also called NAS1669, NAS1670, NAS1750, NAS1751. P/N: NAS1669 (alloy steel protruding head) / NAS1670 (alloy steel flush head) (Visu-Lok II brochure p.6 cross-reference)
Datasheet strength: NAS1669/1670 sheets aren't public. Monogram's listed replacement (PLT5210/5110, alloy steel) is 9,000 lb double shear at 1/4": Visu-Lok II brochure p.4 & p.6.
Standards
- NAS1669
- NAS1670
- NAS1671-NAS1674
- NAS1750/NAS1751 (oversize)
Materials and galvanic compatibility vs CFRP
| Alloy | Shear | vs CFRP | Notes | Source |
|---|---|---|---|---|
| Alloy steel | 85 ksi | high | Alloy steel (NAS1669/NAS1670). Value is for the Monogram PLT5210/5110 listed as its replacement | Derived: Visu-Lok II brochure p.4 alloy steel -6 5,240 lb double shear; p.6 cross-reference |
| A286 CRES | 75 ksi | low | A-286 (NAS1671/NAS1672; replacement PLT5220/5120) | Derived: Visu-Lok II brochure p.4 A-286 row; p.6 cross-reference |
| Aluminum | 50 ksi | high | 7075 nut (NAS1673/NAS1674; replacement PLT5230/5130) | Derived: Visu-Lok II brochure p.4 aluminum row; p.6 cross-reference |
vs CFRP: MIL-STD-889C Table I, graphite column: high = incompatible in all environments; low = compatible except sea-water immersion; unrated = SpecLok has not read a rating for this material.About derived ksi
Specs source: FAA-H-8083-31B (drive nut blind bolts) + Monogram Visu-Lok II brochure ↗: FAA-H-8083-31B p.4-54: construction and install. Heads and materials: Visu-Lok II brochure p.6 cross-reference chart. Strength: Visu-Lok II brochure p.4 for the NAS replacements listed on p.6. Lead-time risk is SpecLok's sourcing assessment, not a datasheet value.
2 head styles
Some variants only partly sourcedNot redrawn: no head dimensions for this variant in the documents on file. The data at right is from the cited document.
Flush head · 100°
- NAS1670: Alloy steel
- NAS1672: A-286
- NAS1674: Aluminum
- NAS1750: Alloy steel, oversize
- NAS1752: A-286, oversize
- NAS1754: Aluminum, oversize
The chart says "FLUSH HEAD". The 100° angle is that of the listed replacements (PLT5110, PLT5120, PLT5130), p.7 "Visu-Lok II, 100° flush head series".
Source: Monogram Visu-Lok II brochure, p.6 "Monogram Part No. vs: NAS Part No. Cross Reference Chart" ↗
The NAS1669 to NAS1674 sheets are not public. Heads and materials are from Monogram's cross-reference chart, which lists each NAS number against the Visu-Lok II part that replaces it; sizes and grips per NAS number are not shown.
Head styles (manufacturer terms)
- Flush head (NAS1670, NAS1672, NAS1674, NAS1750, NAS1752, NAS1754)
- Protruding head (NAS1669, NAS1671, NAS1673, NAS1751, NAS1753, NAS1755)
No install diagram: no manufacturer or public-release government figure of a Jo-Bolt being installed was found. The patent drawings (US 3,643,544) are under source images.
Drive nut blind bolt install steps (FAA-H-8083-31B names Jo-bolts among them), in the handbook's words (not drawn). No Jo-Bolt maker's install procedure was found in a public document.
- “Install the fastener into the hole, and place the installation tooling over the screw (stem) and nut.” FAA-H-8083-31B (AMT Handbook, Airframe), p.4-54, Drive Nut-Type of Blind Bolt ↗
- “Apply torque to the screw with the installation tool while keeping the drive nut stationary. The screw continues to advance through the nut body causing the sleeve to be drawn up over the tapered nose of the nut. When the sleeve forms tightly against the blind side of the structure, the screw fractures in the break groove. The stem of Jo-bolts, Visu-lok®, and Composi-Lok® II fasteners does not break off flush with the head. A screw break-off shaver tool must be used if a flush installation is required.” FAA-H-8083-31B (AMT Handbook, Airframe), p.4-54, Drive Nut-Type of Blind Bolt ↗
Source images (3): patent and government drawings
A patent drawing shows the patented design, which can differ in detail from today's catalog part. Each image says why it is tied to this family.
Official manufacturer install demonstration: Jo-Bolt installation.
Installation verification and preload
Installed preload
Not published in any public document read (FAA-H-8083-31B, Monogram Visu-Lok II brochure). The NAS1669/1670 standards are paywalled.
What to check after install
- "Use the grip gauge available for the type of fastener and select the bolt grip after careful determination of the material thickness. The grip of the bolt is critical for correct installation." (FAA-H-8083-31B p.4-54)
- "The stem of Jo-bolts, Visu-lok®, and Composi-Lok® II fasteners does not break off flush with the head. A screw break-off shaver tool must be used if a flush installation is required." (FAA-H-8083-31B p.4-54)
- No public Jo-Bolt break-off limits, head seating or torque check were found.
Check gauges (1) and sources.Details
- Grip gauge before install (FAA-H-8083-31B p.4-54). No installed-condition gauge is named in a public document.
Sources: FAA-H-8083-31B p.4-54. Acceptance limits belong to the controlling spec; verify against your program's process documentation.
- Tool
- Drive nut blind bolt tooling (FAA-H-8083-31B p.4-54)
- Special / proprietary
- Special tooling
- Training
- "Use the grip gauge available for the type of fastener and select the bolt grip after careful determination of the material thickness. The grip of the bolt is critical for correct installation." (FAA-H-8083-31B p.4-54). No public edge distance or spacing rule was found.
- Inspection
- No public inspection criteria found. The stem "does not break off flush with the head. A screw break-off shaver tool must be used if a flush installation is required" (FAA-H-8083-31B p.4-54).
"During installation, the nut is held stationary while the core bolt is rotated by the installation tooling. The rotation of the core bolt draws the sleeve into the installed position and continues to retain the sleeve for the life of the fastener." "Both powered and hand tooling are available." (FAA-H-8083-31B p.4-54)
The published install tool and nose for each size, other access options, and the gauges that check the install, from the manufacturer's own tool tables.
Tool: Drive nut blind bolt tooling (FAA-H-8083-31B p.4-54)
No Jo-Bolt tool part numbers are published in a public document. FAA-H-8083-31B p.4-54 says drive nut blind bolts (Jo-bolts among them) "are installed with special tooling. Both powered and hand tooling are available." Confirm tools with the fastener supplier.
Full tool tables, envelopes, clearances and source notesCompare tooling burden across all 25 families
Removal
No published removal procedure found; follow the manufacturer's instructions.
P/N series NAS1669 (alloy steel protruding head) / NAS1670 (alloy steel flush head) (Visu-Lok II brochure p.6 cross-reference)Paste a full part number into the decoder.
- Manufacturer
- generic-NAS
- Category
- Hex-drive blind bolt
- FAA-H-8083-31B (drive nut blind bolts) + Monogram Visu-Lok II brochure ↗: FAA-H-8083-31B p.4-54: construction and install. Heads and materials: Visu-Lok II brochure p.6 cross-reference chart. Strength: Visu-Lok II brochure p.4 for the NAS replacements listed on p.6.
Find the part number for your stack
SpecLok has no dash-number table for this family yet: the quote line goes out as the family, part number to be confirmed.
Sourcing
Lead-time risk (SpecLok sourcing assessment): Medium
Get quotes: SpecLok sources this from authorized distributors and returns price, lead time and certs.You buy from the authorized distributor, who is named on your returned quote. SpecLok is free for buyers.
Supply signalfor this family
- 913 NSNs carry a part number of this family, recorded by 36 CAGE codes (FLIS, March 2025).
- Last DoD award for RIVET,BLIND items (FSC 5320): 2026-06-26; 3,082 awards since 2025-10-01.
- No SpecLok quotes yet.
A signal from records SpecLok holds, not availability, stock or a lead-time promise. FLIS lists who has recorded a part number for the item, not who makes it today. DoD awards carry no NSN or part number, so award activity is for the item name's class.
Sources: DLA FLIS Data Electronic Reading Room (PUB LOG) ↗, DLA PUB LOG ↗, USAspending.gov award search API ↗; DoD award data 2025-10-01 to 2026-07-06; compiled 2026-09-28.
Image credits: US 3,643,544, High-strength structural blind fastener for use in airplanes, rockets and the like (Massa), Fig. 2 ↗
Sources (7)
- FAA-H-8083-31B (AMT Handbook, Airframe)
- Jo-Bolt installation video
- Monogram Visu-Lok II brochure
- MIL-STD-889C Table I, graphite column: high = incompatible in all environments; low = compatible except sea-water immersion; unrated = SpecLok has not read a rating for this material.
- DLA FLIS Data Electronic Reading Room (PUB LOG)
- DLA PUB LOG
- USAspending.gov award search API
Next · Find
Check Jo-Bolt against your joint
Describe the joint in the selector to see how this family ranks, with the cited design rules.