SkyLoc QL8C78 Threaded Receptacle
Quad-Lead Thread | 7/16-20 UNF Mounting | Six-Piece Assembly | 303 Stainless Steel
Technical Overview
The QL8C78 threaded receptacle is a precision six-piece assembly engineered for fastening systems requiring threaded installation. The assembly features a 303 stainless steel threaded barrel with 7/16-20 UNF-2A external mounting threads and .1640-32 UNC-3A quad-lead internal cam groove for stud engagement. Internal components include dual spring-loaded cam assemblies, nested 17-7 PH stainless steel compression springs, and an A286 stainless steel internal stud with dry film lubricant per MIL-PRF-46010. This design provides reliable quarter-turn operation with 7/16-20 UNF mounting threads for installation into tapped holes or threaded mounting plates. Manufactured to AS9100D quality standards and interchangeable with CA18178 receptacles.
Specifications
| Thread Size - Stud Interface: |
.1640-32 UNC-3A (4-Lead internal cam groove) |
| Thread Size - Mounting: |
7/16-20 UNF-2A (modified major diameter .430" max) |
| Receptacle Type: |
Threaded Receptacle for Tapped Installations |
| Assembly Components: |
6 pieces (barrel, upper cam, lower cam, 2 springs, internal stud) |
| Barrel Material: |
303 Stainless Steel (ASTM A582), Passivated per AMS 2700 |
| Upper Cam Material: |
Metalic, Black Oxide per MIL-DTL-13924 Class 1 |
| Lower Cam Material: |
304 Stainless Steel (ASTM B853), Passivated per AMS 2700 |
| Spring Materials: |
17-7 PH Stainless Steel (ASTM A313), Passivated per AMS 2700 |
| Internal Stud Material: |
A286 Stainless Steel, Heat Treated to 140 KSI, Passivated per AMS 2700, Dry Film Lube per MIL-PRF-46010 |
| Overall Diameter: |
.382" (body) / .453" (mounting flange) |
| Overall Height: |
.590" / .530" |
| Compatible Systems: |
QL8C Series Quarter-Turn Studs |
| Equivalent Part Number: |
CA18178 |
| Compliance: |
AS9100D Certified, CAGE Code 435Z0 |
Applications
- Aerospace: Structural panels, inspection access doors, engine cowlings requiring threaded receptacle installation in tapped holes
- Motorsport: Body panels, chassis components, quick-access covers in applications with pre-tapped mounting locations
- Industrial: Equipment enclosures, machinery panels, control cabinets with threaded mounting provisions
- Marine: Deck hatches, structural assemblies in corrosive environments requiring threaded quarter-turn receptacles
- Defense: Military aircraft structural panels, ground support equipment requiring threaded receptacle mounting
Complete System Components
| Component | Part Number | Description |
| Stud |
QL8C21-XPH |
Pan head stud, slotted (select dash number for grip) |
| Receptacle Options |
QL8C62 |
Kee'd threaded insert, self-locking (NSN 5325-00-761-6222) |
| QL8C64 Series |
Threaded receptacle for tapped installations (this product) |
| QL8C66 Series |
Caged floating receptacle for radial float applications |
| Retainer |
QL8C61 |
Spring retainer for loose panel applications |
| Grommet |
QL8C63 Series |
Load distribution and panel protection |
Key Features
- 7/16-20 UNF Threading: Fine thread design provides secure mounting in tapped holes with excellent thread engagement
- Six-Piece Assembly: Precision-engineered components work together to provide reliable quarter-turn operation
- Dual Cam System: Upper and lower cam assemblies with nested compression springs ensure consistent stud engagement
- Quad-Lead Thread: Four-start internal cam groove allows 90-degree rotation for rapid quarter-turn fastening
- High-Strength Internal Stud: A286 stainless steel heat treated to 140 KSI with dry film lubricant for smooth operation
- Corrosion-Resistant Materials: 303 and 304 stainless steel construction with passivation for long-term durability
- Compact Design: .382" body diameter allows installation in space-constrained applications
- Industry Standard Interchange: Compatible with CA18178 receptacles
📏 Installation Guide: The QL8C78 threaded receptacle requires a tapped 7/16-20 UNF hole for installation. The fine thread design provides excellent thread engagement and secure mounting. Ensure proper thread depth and installation torque for optimal performance. This receptacle is ideal for applications with pre-tapped mounting locations requiring reliable quarter-turn fastening without the need for bonded or riveted installation methods.
Quality & Compliance
Manufactured by Skybolt Aerospace Fasteners under AS9100D certification at our Leesburg, Florida facility (CAGE Code: 435Z0). All QL8C78 receptacle assemblies are 100% inspected to drawing specifications and include full material traceability. Materials conform to ASTM A582 for 303 stainless steel, ASTM B853 for 304 stainless steel, ASTM A313 for 17-7 PH spring steel, and AMS 5731/5737 for A286 stainless steel. Black oxide finish on upper cam meets MIL-DTL-13924 Class 1 requirements. Dry film lubricant meets MIL-PRF-46010 specifications for enhanced performance.
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.
