SkyLoc QL4-21 Caged Floating Receptacle
Three-Piece Assembly | Radial Float Design | 4140 High-Strength Steel
Technical Overview
The QL4-21 caged floating receptacle is a precision three-piece assembly engineered for structural applications requiring radial float capability. The assembly consists of the QL4-NUT (threaded insert with 1/4-28 UNF-3B two-lead thread), QL4C-CAGE (17-7 PH stainless steel spring cage), and QL4-BASE (mounting base). This design allows controlled radial movement to accommodate hole misalignment and panel tolerances while maintaining secure fastening capability. Manufactured from 4140 steel heat treated to 180-200 KSI with cadmium plating per AMS QQ-P-416 Type II, Class 2 and dry film lubricant, this receptacle provides exceptional strength and corrosion resistance for demanding aerospace and industrial installations.
Specifications
| Assembly Components: |
QL4-NUT, QL4C-CAGE, QL4-BASE |
| Thread Size: |
1/4-28 UNF-3B (2-Lead Thread) |
| Receptacle Type: |
Caged Floating with Radial Float Capability |
| Nut & Base Material: |
4140 Steel (ASTM A29) |
| Cage Material: |
17-7 PH Stainless Steel (ASTM A564) |
| Heat Treatment: |
180-200 KSI per AMS 2759 (nut & base), TH1050 (cage) |
| Finish: |
Cadmium Plate per AMS QQ-P-416 Type II, Class 2 with Dry Film Lubricant (nut & base), Passivated per AMS 2700 (cage) |
| Float Capability: |
Radial float for hole misalignment accommodation |
| Compatible Systems: |
QL4S Series Quarter-Turn Studs |
| Equivalent Part Number: |
CA21021 Series |
| Compliance: |
AS9100D Certified, CAGE Code 435Z0 |
Applications
- Aerospace: Structural panels requiring hole misalignment tolerance, engine cowlings, access doors where radial float compensates for assembly tolerances
- Motorsport: Body panels, chassis components, applications requiring quick-release capability with tolerance accommodation
- Industrial: Equipment enclosures, machinery panels, installations requiring radial movement to accommodate thermal expansion or structural flexing
- Marine: Deck hardware, structural assemblies in corrosive environments requiring float capability
- Defense: Military aircraft structural panels, ground support equipment requiring MIL-SPEC corrosion protection with radial float
QL4-21 Assembly Components
| Component | Part Number | Description |
| Nut |
QL4-NUT |
Threaded insert with 1/4-28 UNF-3B two-lead thread, 4140 steel, cadmium plated with dry film lube |
| Cage |
QL4C-CAGE |
Spring cage for radial float, 17-7 PH stainless steel, passivated |
| Base |
QL4-BASE |
Mounting base, 4140 steel, cadmium plated with dry film lube |
Complete System Components
| Component | Part Number | Description |
| Stud |
QL4S Series |
Quarter-turn studs compatible with 1/4-28 two-lead thread receptacles |
| Receptacle |
QL4-21 |
Caged floating receptacle assembly (this product) |
| Retainer |
QL4S-RET Series |
Spring retainers for loose panel applications |
| Grommet |
QL4G Series |
Load distribution and panel protection |
Key Features
- Radial Float Design: Spring cage allows controlled radial movement to accommodate hole misalignment and assembly tolerances
- Three-Piece Construction: Modular design with nut, cage, and base components for reliable performance and serviceability
- High-Strength Materials: 4140 steel heat treated to 180-200 KSI provides superior load capacity for structural applications
- Corrosion Protection: Cadmium plating per AMS QQ-P-416 Type II, Class 2 with dry film lubricant for harsh environment durability
- Two-Lead Thread: 1/4-28 UNF-3B dual-start thread enables 180-degree rotation for rapid quarter-turn fastening
- Industry Standard Interchange: Compatible with CA21021 series receptacles
📏 Selection Guide: Use QL4-21 caged floating receptacles in applications requiring radial float to accommodate hole misalignment, structural movement, or thermal expansion. The three-piece assembly provides reliable quarter-turn fastening while allowing controlled radial movement. Individual components (QL4-NUT, QL4C-CAGE, QL4-BASE) are available separately for service and replacement - contact sales for component ordering information.
Quality & Compliance
Manufactured by Skybolt Aerospace Fasteners under AS9100D certification at our Leesburg, Florida facility (CAGE Code: 435Z0). All QL4-21 receptacle assemblies are 100% inspected to drawing specifications and include full material traceability. Materials conform to ASTM A29 for 4140 alloy steel and ASTM A564 for 17-7 PH stainless steel. Heat treatment meets AMS 2759 requirements for 180-200 KSI ultimate tensile strength. Cadmium plating on nut and base components meets AMS QQ-P-416 Type II, Class 2 requirements with dry film lubricant for enhanced performance in aerospace and military applications.
Tridair® is a registered trademark of Howmet Aerospace, Inc. or its subsidiaries. Skybolt products are compatible alternatives and are not manufactured by or affiliated with Howmet Aerospace.
