Visu-Lok
Monogram · Hex-drive blind bolt
Blind bolt that proves its own install — the spent nut tells you it's seated.
aka VisuLok · hex-drive blind bolt
Schematic cross-section, not to scale. Orange = hex drive + large blind-side upset.
Shear
75–95 ksi
Blind bulb
large
Max service
≤ 1200°F
Lead-time risk
High
Diameters
3/16, 1/4, 5/16, 3/8"
Head styles
- Protruding
- 100° flush
- 130° flush (composite)
Standards
- NAS (Visu-Lok series)
Materials & galvanic compatibility vs CFRP
| Alloy | Shear | vs CFRP | Notes |
|---|---|---|---|
| A286 CRES | 95 ksi | med | — |
| Titanium (Ti-6Al-4V) | 95 ksi | low | — |
| Alloy steel | 95 ksi | med | — |
| Inconel | 95 ksi | low | high-temp |
Install tooling & training
- Tool
- Hex driver (disposable hex-drive nut)
- Special / proprietary
- Special tooling · proprietary
- Training
- Specialty; torque/clamp control on composite.
- Inspection
- Visual — nut sheared off = correct install.
Self-locking blind head with guaranteed ~20% minimum preload; spent hex-drive nut on the discarded pintail gives positive visual confirmation of a complete install.
Sourcing
Lead-time risk: High
- Peerless Aerospace Fastener ↗
Largest dedicated aerospace fastener inventory; approved source for major OEMs + DoD; multi-year fixed pricing, bonded storage, designated hold-shelf, min/max + safety-stock programs.
- Incora ↗
Authorized distributor for 60+ manufacturers; AS9100 / EN9120 / FAA AC 00-56; strong vendor-managed-inventory (VMI) and kitting programs.
Need a price or lead time?
Build a spec-complete RFQ and send it to distributors who stock Visu-Lok.
Strengths
- +Positive visual install verification
- +Guaranteed minimum preload
- +Many alloys incl. high-temp Inconel
Trade-offs
- −Specialty tooling + training
- −Long lead times
Typical applications
- · Structural joints needing visible install verification
- · Severe-fatigue fixed/rotary-wing (tapered variant)
- · Composite-clearance assemblies