Skybolt - SkyLoc® Structural Fasteners / SkyLoc® External Thread (EXT) Series / SkyLoc® EXT Retainers

QL4S-RET2

Tue, 6 Jan 2026 06:38:13 GMT

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)
Retainer Options	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.

Visit SkyLoc® EXT Retainers to see additional products in this category.

QL4S-RET1

Tue, 6 Jan 2026 06:08:44 GMT

QL4S-RET1
Buy Now: $4.98