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

QL4C-3G-CAD

Tue, 6 Jan 2026 10:50:13 GMT

SkyLoc QL4C Grommet Series

Load Distribution | Panel Protection | 304 Stainless Steel | Multiple Grip Ranges

Technical Overview

The QL4C grommet series provides essential load distribution and panel protection for quarter-turn fastening systems. Manufactured from 304 stainless steel and heat treated to Condition A, these grommets distribute fastener loads across a wider panel area, reducing stress concentration and preventing panel damage. Available in three grip ranges (-1G, -2G, -3G) to accommodate various panel thicknesses from .075" to .155", the grommet series features a precision-formed cup design that interfaces between the stud head and panel surface. Two finish options are available: passivated for general aerospace applications (QL4C-XG) and cadmium plated Type II, Class 2 for enhanced corrosion protection (QL4C-XG-CAD).

Specifications

Nominal Size:	1/4"
Material:	304 Stainless Steel
Heat Treatment:	Condition A
Grip Range Coverage:	.075" – .155" (dash number dependent)
Diameter (A):	.505" max
Center Hole (C):	.255" / .250"
Reference Dimension (E):	.310"
Compatible Systems:	QL4S Series Quarter-Turn Studs
Equivalent Part Numbers:	CA21038-4 Series, CA21038C-4 Series
Compliance:	AS9100D Certified, CAGE Code 435Z0

Applications

Aerospace: Composite panels, thin-gauge sheet metal, applications requiring load distribution to prevent panel dimpling or stress cracking
Motorsport: Carbon fiber bodywork, lightweight panels, high-vibration applications requiring load spreading
Industrial: Thin panel installations, equipment enclosures, applications requiring surface protection from fastener bearing loads
Marine: Deck panels, thin-wall structures in corrosive environments requiring load distribution and panel protection
Defense: Military aircraft composite structures, lightweight panels requiring optimized load distribution

Grommet Variants

Part Number	Grip Range	Finish	Equivalent Part
QL4C-1G	.075" – .095"	Passivated	CA21038-4-1
QL4C-2G	.096" – .115"	Passivated	CA21038-4-2
QL4C-3G	.116" – .135"	Passivated	CA21038-4-3
QL4C-1G-CAD	.075" – .095"	Cadmium Plated, Type II, Class 2	CA21038C-4-1
QL4C-2G-CAD	.096" – .115"	Cadmium Plated, Type II, Class 2	CA21038C-4-2
QL4C-3G-CAD	.116" – .135"	Cadmium Plated, Type II, Class 2	CA21038C-4-3

Complete System Components

Component	Part Number	Description
Stud	QL4S-EXT Series	Studs compatible with 1/4-28 two-lead thread receptacles
Receptacle	QL4-21	Caged receptacle assembly
Retainer	QL4S-RET Series	Spring retainers for loose panel applications
Grommet	QL4C-XG / QL4C-XG-CAD	Load distribution and panel protection (this product)

Key Features

Load Distribution: Precision-formed cup design distributes fastener loads across a wider panel area, preventing stress concentration and panel damage
Panel Protection: Creates protective interface between stud head and panel surface, preventing wear and surface damage
304 Stainless Steel: Corrosion-resistant material provides long service life in demanding environments
Multiple Grip Ranges: Three grip ranges (-1G, -2G, -3G) accommodate panel thicknesses from .075" to .135"
Two Finish Options: Passivated (QL4C-XG) for general use, cadmium plated (QL4C-XG-CAD) for enhanced corrosion protection
Industry Standard Interchange: Compatible with CA21038-4 and CA21038C-4 series grommets

📏 Selection Guide: Select grommet dash number (-1G, -2G, or -3G) based on panel thickness to ensure proper fit and load distribution. Choose passivated finish (QL4C-XG) for general aerospace applications or cadmium plated finish (QL4C-XG-CAD) for enhanced corrosion protection in marine, military, and harsh environment installations. Grommets are essential for thin panels, composite materials, and applications requiring optimized load distribution.

Quality & Compliance

Manufactured by Skybolt Aerospace Fasteners under AS9100D certification at our Leesburg, Florida facility (CAGE Code: 435Z0). All QL4C grommets are 100% inspected to drawing specifications and include full material traceability. Material conforms to 304 stainless steel specifications with heat treatment to Condition A. Cadmium plating on QL4C-XG-CAD variants meets AMS QQ-P-416 Type II, Class 2 requirements for 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.

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

QL4C-2G-CAD

Tue, 6 Jan 2026 10:48:51 GMT

QL4C-2G-CAD
Buy Now: $15.99

SkyLoc QL4C Grommet Series

Load Distribution | Panel Protection | 304 Stainless Steel | Multiple Grip Ranges

Technical Overview

Specifications

Nominal Size:	1/4"
Material:	304 Stainless Steel
Heat Treatment:	Condition A
Grip Range Coverage:	.075" – .155" (dash number dependent)
Diameter (A):	.505" max
Center Hole (C):	.255" / .250"
Reference Dimension (E):	.310"
Compatible Systems:	QL4S Series Quarter-Turn Studs
Equivalent Part Numbers:	CA21038-4 Series, CA21038C-4 Series
Compliance:	AS9100D Certified, CAGE Code 435Z0

Applications

Aerospace: Composite panels, thin-gauge sheet metal, applications requiring load distribution to prevent panel dimpling or stress cracking
Motorsport: Carbon fiber bodywork, lightweight panels, high-vibration applications requiring load spreading
Industrial: Thin panel installations, equipment enclosures, applications requiring surface protection from fastener bearing loads
Marine: Deck panels, thin-wall structures in corrosive environments requiring load distribution and panel protection
Defense: Military aircraft composite structures, lightweight panels requiring optimized load distribution

Grommet Variants

Part Number	Grip Range	Finish	Equivalent Part
QL4C-1G	.075" – .095"	Passivated	CA21038-4-1
QL4C-2G	.096" – .115"	Passivated	CA21038-4-2
QL4C-3G	.116" – .135"	Passivated	CA21038-4-3
QL4C-1G-CAD	.075" – .095"	Cadmium Plated, Type II, Class 2	CA21038C-4-1
QL4C-2G-CAD	.096" – .115"	Cadmium Plated, Type II, Class 2	CA21038C-4-2
QL4C-3G-CAD	.116" – .135"	Cadmium Plated, Type II, Class 2	CA21038C-4-3

Complete System Components

Component	Part Number	Description
Stud	QL4S-EXT Series	Studs compatible with 1/4-28 two-lead thread receptacles
Receptacle	QL4-21	Caged receptacle assembly
Retainer	QL4S-RET Series	Spring retainers for loose panel applications
Grommet	QL4C-XG / QL4C-XG-CAD	Load distribution and panel protection (this product)

Key Features

Load Distribution: Precision-formed cup design distributes fastener loads across a wider panel area, preventing stress concentration and panel damage
Panel Protection: Creates protective interface between stud head and panel surface, preventing wear and surface damage
304 Stainless Steel: Corrosion-resistant material provides long service life in demanding environments
Multiple Grip Ranges: Three grip ranges (-1G, -2G, -3G) accommodate panel thicknesses from .075" to .135"
Two Finish Options: Passivated (QL4C-XG) for general use, cadmium plated (QL4C-XG-CAD) for enhanced corrosion protection
Industry Standard Interchange: Compatible with CA21038-4 and CA21038C-4 series grommets

Quality & Compliance

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.

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

QL4C-1G-CAD

Tue, 6 Jan 2026 10:46:51 GMT

QL4C-1G-CAD
Buy Now: $15.00

SkyLoc QL4C Grommet Series

Load Distribution | Panel Protection | 304 Stainless Steel | Multiple Grip Ranges

Technical Overview

Specifications

Nominal Size:	1/4"
Material:	304 Stainless Steel
Heat Treatment:	Condition A
Grip Range Coverage:	.075" – .155" (dash number dependent)
Diameter (A):	.505" max
Center Hole (C):	.255" / .250"
Reference Dimension (E):	.310"
Compatible Systems:	QL4S Series Quarter-Turn Studs
Equivalent Part Numbers:	CA21038-4 Series, CA21038C-4 Series
Compliance:	AS9100D Certified, CAGE Code 435Z0

Applications

Aerospace: Composite panels, thin-gauge sheet metal, applications requiring load distribution to prevent panel dimpling or stress cracking
Motorsport: Carbon fiber bodywork, lightweight panels, high-vibration applications requiring load spreading
Industrial: Thin panel installations, equipment enclosures, applications requiring surface protection from fastener bearing loads
Marine: Deck panels, thin-wall structures in corrosive environments requiring load distribution and panel protection
Defense: Military aircraft composite structures, lightweight panels requiring optimized load distribution

Grommet Variants

Part Number	Grip Range	Finish	Equivalent Part
QL4C-1G	.075" – .095"	Passivated	CA21038-4-1
QL4C-2G	.096" – .115"	Passivated	CA21038-4-2
QL4C-3G	.116" – .135"	Passivated	CA21038-4-3
QL4C-1G-CAD	.075" – .095"	Cadmium Plated, Type II, Class 2	CA21038C-4-1
QL4C-2G-CAD	.096" – .115"	Cadmium Plated, Type II, Class 2	CA21038C-4-2
QL4C-3G-CAD	.116" – .135"	Cadmium Plated, Type II, Class 2	CA21038C-4-3

Complete System Components

Component	Part Number	Description
Stud	QL4S-EXT Series	Studs compatible with 1/4-28 two-lead thread receptacles
Receptacle	QL4-21	Caged receptacle assembly
Retainer	QL4S-RET Series	Spring retainers for loose panel applications
Grommet	QL4C-XG / QL4C-XG-CAD	Load distribution and panel protection (this product)

Key Features

Load Distribution: Precision-formed cup design distributes fastener loads across a wider panel area, preventing stress concentration and panel damage
Panel Protection: Creates protective interface between stud head and panel surface, preventing wear and surface damage
304 Stainless Steel: Corrosion-resistant material provides long service life in demanding environments
Multiple Grip Ranges: Three grip ranges (-1G, -2G, -3G) accommodate panel thicknesses from .075" to .135"
Two Finish Options: Passivated (QL4C-XG) for general use, cadmium plated (QL4C-XG-CAD) for enhanced corrosion protection
Industry Standard Interchange: Compatible with CA21038-4 and CA21038C-4 series grommets

Quality & Compliance

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.

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

QL4C-3G

Tue, 6 Jan 2026 10:41:35 GMT

QL4C-3G
Buy Now: $15.73

SkyLoc QL4C Grommet Series

Load Distribution | Panel Protection | 304 Stainless Steel | Multiple Grip Ranges

Technical Overview

Specifications

Nominal Size:	1/4"
Material:	304 Stainless Steel
Heat Treatment:	Condition A
Grip Range Coverage:	.075" – .155" (dash number dependent)
Diameter (A):	.505" max
Center Hole (C):	.255" / .250"
Reference Dimension (E):	.310"
Compatible Systems:	QL4S Series Quarter-Turn Studs
Equivalent Part Numbers:	CA21038-4 Series, CA21038C-4 Series
Compliance:	AS9100D Certified, CAGE Code 435Z0

Applications

Aerospace: Composite panels, thin-gauge sheet metal, applications requiring load distribution to prevent panel dimpling or stress cracking
Motorsport: Carbon fiber bodywork, lightweight panels, high-vibration applications requiring load spreading
Industrial: Thin panel installations, equipment enclosures, applications requiring surface protection from fastener bearing loads
Marine: Deck panels, thin-wall structures in corrosive environments requiring load distribution and panel protection
Defense: Military aircraft composite structures, lightweight panels requiring optimized load distribution

Grommet Variants

Part Number	Grip Range	Finish	Equivalent Part
QL4C-1G	.075" – .095"	Passivated	CA21038-4-1
QL4C-2G	.096" – .115"	Passivated	CA21038-4-2
QL4C-3G	.116" – .135"	Passivated	CA21038-4-3
QL4C-1G-CAD	.075" – .095"	Cadmium Plated, Type II, Class 2	CA21038C-4-1
QL4C-2G-CAD	.096" – .115"	Cadmium Plated, Type II, Class 2	CA21038C-4-2
QL4C-3G-CAD	.116" – .135"	Cadmium Plated, Type II, Class 2	CA21038C-4-3

Complete System Components

Component	Part Number	Description
Stud	QL4S-EXT Series	Studs compatible with 1/4-28 two-lead thread receptacles
Receptacle	QL4-21	Caged receptacle assembly
Retainer	QL4S-RET Series	Spring retainers for loose panel applications
Grommet	QL4C-XG / QL4C-XG-CAD	Load distribution and panel protection (this product)

Key Features

Load Distribution: Precision-formed cup design distributes fastener loads across a wider panel area, preventing stress concentration and panel damage
Panel Protection: Creates protective interface between stud head and panel surface, preventing wear and surface damage
304 Stainless Steel: Corrosion-resistant material provides long service life in demanding environments
Multiple Grip Ranges: Three grip ranges (-1G, -2G, -3G) accommodate panel thicknesses from .075" to .135"
Two Finish Options: Passivated (QL4C-XG) for general use, cadmium plated (QL4C-XG-CAD) for enhanced corrosion protection
Industry Standard Interchange: Compatible with CA21038-4 and CA21038C-4 series grommets

Quality & Compliance

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.

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

QL4C-2G

Tue, 6 Jan 2026 10:41:35 GMT

QL4C-2G
Buy Now: $14.96

SkyLoc QL4C Grommet Series

Load Distribution | Panel Protection | 304 Stainless Steel | Multiple Grip Ranges

Technical Overview

Specifications

Nominal Size:	1/4"
Material:	304 Stainless Steel
Heat Treatment:	Condition A
Grip Range Coverage:	.075" – .155" (dash number dependent)
Diameter (A):	.505" max
Center Hole (C):	.255" / .250"
Reference Dimension (E):	.310"
Compatible Systems:	QL4S Series Quarter-Turn Studs
Equivalent Part Numbers:	CA21038-4 Series, CA21038C-4 Series
Compliance:	AS9100D Certified, CAGE Code 435Z0

Applications

Aerospace: Composite panels, thin-gauge sheet metal, applications requiring load distribution to prevent panel dimpling or stress cracking
Motorsport: Carbon fiber bodywork, lightweight panels, high-vibration applications requiring load spreading
Industrial: Thin panel installations, equipment enclosures, applications requiring surface protection from fastener bearing loads
Marine: Deck panels, thin-wall structures in corrosive environments requiring load distribution and panel protection
Defense: Military aircraft composite structures, lightweight panels requiring optimized load distribution

Grommet Variants

Part Number	Grip Range	Finish	Equivalent Part
QL4C-1G	.075" – .095"	Passivated	CA21038-4-1
QL4C-2G	.096" – .115"	Passivated	CA21038-4-2
QL4C-3G	.116" – .135"	Passivated	CA21038-4-3
QL4C-1G-CAD	.075" – .095"	Cadmium Plated, Type II, Class 2	CA21038C-4-1
QL4C-2G-CAD	.096" – .115"	Cadmium Plated, Type II, Class 2	CA21038C-4-2
QL4C-3G-CAD	.116" – .135"	Cadmium Plated, Type II, Class 2	CA21038C-4-3

Complete System Components

Component	Part Number	Description
Stud	QL4S-EXT Series	Studs compatible with 1/4-28 two-lead thread receptacles
Receptacle	QL4-21	Caged receptacle assembly
Retainer	QL4S-RET Series	Spring retainers for loose panel applications
Grommet	QL4C-XG / QL4C-XG-CAD	Load distribution and panel protection (this product)

Key Features

Load Distribution: Precision-formed cup design distributes fastener loads across a wider panel area, preventing stress concentration and panel damage
Panel Protection: Creates protective interface between stud head and panel surface, preventing wear and surface damage
304 Stainless Steel: Corrosion-resistant material provides long service life in demanding environments
Multiple Grip Ranges: Three grip ranges (-1G, -2G, -3G) accommodate panel thicknesses from .075" to .135"
Two Finish Options: Passivated (QL4C-XG) for general use, cadmium plated (QL4C-XG-CAD) for enhanced corrosion protection
Industry Standard Interchange: Compatible with CA21038-4 and CA21038C-4 series grommets

Quality & Compliance

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.

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

QL4C-1G

Tue, 6 Jan 2026 08:14:45 GMT

QL4C-1G
Buy Now: $14.45

SkyLoc QL4C Grommet Series

Load Distribution | Panel Protection | 304 Stainless Steel | Multiple Grip Ranges

Technical Overview

Specifications

Nominal Size:	1/4"
Material:	304 Stainless Steel
Heat Treatment:	Condition A
Grip Range Coverage:	.075" – .155" (dash number dependent)
Diameter (A):	.505" max
Center Hole (C):	.255" / .250"
Reference Dimension (E):	.310"
Compatible Systems:	QL4S Series Quarter-Turn Studs
Equivalent Part Numbers:	CA21038-4 Series, CA21038C-4 Series
Compliance:	AS9100D Certified, CAGE Code 435Z0

Applications

Aerospace: Composite panels, thin-gauge sheet metal, applications requiring load distribution to prevent panel dimpling or stress cracking
Motorsport: Carbon fiber bodywork, lightweight panels, high-vibration applications requiring load spreading
Industrial: Thin panel installations, equipment enclosures, applications requiring surface protection from fastener bearing loads
Marine: Deck panels, thin-wall structures in corrosive environments requiring load distribution and panel protection
Defense: Military aircraft composite structures, lightweight panels requiring optimized load distribution

Grommet Variants

Part Number	Grip Range	Finish	Equivalent Part
QL4C-1G	.075" – .095"	Passivated	CA21038-4-1
QL4C-2G	.096" – .115"	Passivated	CA21038-4-2
QL4C-3G	.116" – .135"	Passivated	CA21038-4-3
QL4C-1G-CAD	.075" – .095"	Cadmium Plated, Type II, Class 2	CA21038C-4-1
QL4C-2G-CAD	.096" – .115"	Cadmium Plated, Type II, Class 2	CA21038C-4-2
QL4C-3G-CAD	.116" – .135"	Cadmium Plated, Type II, Class 2	CA21038C-4-3

Complete System Components

Component	Part Number	Description
Stud	QL4S-EXT Series	Studs compatible with 1/4-28 two-lead thread receptacles
Receptacle	QL4-21	Caged receptacle assembly
Retainer	QL4S-RET Series	Spring retainers for loose panel applications
Grommet	QL4C-XG / QL4C-XG-CAD	Load distribution and panel protection (this product)

Key Features

Load Distribution: Precision-formed cup design distributes fastener loads across a wider panel area, preventing stress concentration and panel damage
Panel Protection: Creates protective interface between stud head and panel surface, preventing wear and surface damage
304 Stainless Steel: Corrosion-resistant material provides long service life in demanding environments
Multiple Grip Ranges: Three grip ranges (-1G, -2G, -3G) accommodate panel thicknesses from .075" to .135"
Two Finish Options: Passivated (QL4C-XG) for general use, cadmium plated (QL4C-XG-CAD) for enhanced corrosion protection
Industry Standard Interchange: Compatible with CA21038-4 and CA21038C-4 series grommets

Quality & Compliance

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.

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