SkyLoc QL4S-RET1 / QL4S-RET2 Spring Retainer
17-7 PH Stainless Steel | Precision Spring Design | EXT Series Compatible
Technical Overview
The QL4S-RET spring retainer is a precision-engineered panel retention component designed for use with QL4S-EXT extended thread stud systems. Manufactured from 17-7 PH precipitation hardening stainless steel and heat treated to Condition RH 950, this retainer provides consistent spring tension to maintain positive panel contact in loose panel applications. The retainer's engineered spring geometry ensures reliable retention force while allowing for panel movement and thermal expansion. Available in two finish options: QL4S-RET1 (passivated) for general aerospace applications and QL4S-RET2 (cadmium plated Type II, Class 2) for enhanced corrosion protection. This retainer is equivalent to CA21037-4R series and is interchangeable with industry standard parts.
Specifications
| Nominal Size: |
1/4" |
| Material: |
17-7 PH Stainless Steel (Precipitation Hardening) |
| Heat Treatment: |
Condition RH 950 |
| Finish - QL4S-RET1: |
Passivated |
| Finish - QL4S-RET2: |
Cadmium Plated (Type II, Class 2) |
| Reference Diameter: |
.355" |
| Weight: |
.35 lbs per 1000 pieces (max) |
| Compatible Systems: |
QL4S-EXT Extended Thread Stud Series |
| Equivalent Part Numbers: |
CA21037-4R, CA21037C-4R, SK-21212 |
| Compliance: |
AS9100D Certified, CAGE Code 435Z0 |
Applications
- Aerospace: Loose panel installations, inspection panels, engine cowlings where panel flotation is required to accommodate thermal expansion
- Motorsport: Body panels, fairings, quick-access covers requiring retention force without rigid mounting
- Industrial: Equipment enclosures, access panels, applications requiring panel retention with movement capability
- Marine: Deck panels, hatches, corrosive environment installations requiring stainless steel spring properties
- Defense: Military aircraft loose panel applications, ground support equipment requiring MIL-SPEC finishes
Complete System Components
| Component | Part Number | Description |
| Stud |
QL4S-EXT# |
Flush head extended thread stud, 9/64" hex (select dash number for grip) |
| Receptacle |
QL4-21 |
Caged floating receptacle assembly for radial float applications |
| Retainer Options |
QL4S-RET1 |
Spring retainer, passivated finish (this product) |
| QL4S-RET2 |
Spring retainer, cadmium plated Type II, Class 2 (this product) |
| Grommet |
QL4C-#G |
Load distribution and panel protection for flush installations |
Key Features
- Precision Spring Design: Engineered spring geometry provides consistent retention force across temperature ranges and repeated cycling
- High-Strength Stainless: 17-7 PH stainless steel with RH 950 heat treatment delivers superior spring properties and corrosion resistance
- Two Finish Options: QL4S-RET1 (passivated) for general applications, QL4S-RET2 (cadmium plated) for enhanced corrosion protection
- Loose Panel Capability: Allows controlled panel movement while maintaining positive retention force
- Lightweight Design: Minimal weight impact at .35 lbs per 1000 pieces for weight-critical applications
- Industry Standard Interchange: Compatible with CA21037-4R, CA21037C-4R, and SK-21212 equivalent systems
📏 Selection Guide: Use QL4S-RET spring retainers in loose panel installations where the panel must be retained but allowed to float or move. Select QL4S-RET1 (passivated) for general aerospace applications or QL4S-RET2 (cadmium plated) for enhanced corrosion resistance in marine, military, and harsh environment applications. Ensure compatibility with QL4S-EXT extended thread stud systems.
Quality & Compliance
Manufactured by Skybolt Aerospace Fasteners under AS9100D certification at our Leesburg, Florida facility (CAGE Code: 435Z0). All QL4S-RET retainers are 100% inspected to drawing specifications and include full material traceability. Material conforms to 17-7 PH precipitation hardening stainless steel specifications with heat treatment to Condition RH 950 for optimized spring properties. Cadmium plating on QL4S-RET2 meets AMS QQ-P-416 Type II, Class 2 requirements for aerospace and military applications.
