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HELI-COIL Helical Insert: Tanged Tang Style, Screw-Locking, 1/4"-28 Thread Size, Plain - Screw-Locking Tanged Helical Inserts
HELI-COILScrew-Locking Tanged Helical Inserts

HELI-COIL Helical Insert: Tanged Tang Style, Screw-Locking, 1/4"-28 Thread Size, Plain

The HELI-COIL Helical Insert is a tanged tang style, screw-locking insert in a plain finish, supplied in a 100-piece pack. It features a 1/4"-28 fine thread size, right-hand thread direction, and an 18-8 material…

SKU 3G-OTH-528798

Brand
HELI-COIL
Item
Helical Insert: Tanged Tang Style, Screw-Locking, 1/4"-28 Thread Size, Plain
Category
Screw-Locking Tanged Helical Inserts
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Technical Specifications

HELI-COIL
Manufacturer Part Number
A3591-4CN375
Type
Screw-Locking, Plain, 100 PK
Tensile Strength
200,000 to 250,000 psi
Finish Type
Plain
Thread Size
1/4"-28
Thread Type
Fine
STI Tap Size
1/4"-28
Thread Direction
Right Hand
Compatible Material
Metal
Material Grade/Class
18-8
System of Measurement
Inch
View Full Spec Sheet

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HELI-COIL Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The HELI-COIL Helical Insert is a tanged tang style, screw-locking insert in a plain finish, supplied in a 100-piece pack. It features a 1/4"-28 fine thread size, right-hand thread direction, and an 18-8 material grade/class with a tensile strength of 200,000 to 250,000 psi. Designed for metal compatibility, this inch-system insert uses an STI tap size of 1/4"-28 (MPN A3591-4CN375).

Frequently Asked Questions

What is a HELI-COIL helical insert used for?

A HELI-COIL helical insert repairs or reinforces threads in metal. This screw-locking, tanged tang style insert with 1/4"-28 fine threads provides strong, wear-resistant threads in aluminum, cast iron, or steel. It is ideal for automotive, aerospace, and industrial maintenance applications where thread integrity is critical.

What are the specifications of the HELI-COIL A3591-4CN375 insert?

This HELI-COIL insert has a 1/4"-28 fine thread size, right-hand thread direction, and an 18-8 material grade with tensile strength of 200,000 to 250,000 psi. It uses an STI tap size of 1/4"-28, is compatible with metal, and comes in a plain finish, 100-piece pack.

Where to buy HELI-COIL helical inserts worldwide?

3G Electric supplies HELI-COIL helical inserts worldwide. As a global industrial solutions provider, we handle full logistics and customs clearance to deliver the A3591-4CN375 screw-locking insert to your facility. Contact us for pricing and lead time on this 100-pack of 1/4"-28 inserts.

How to install a HELI-COIL tanged helical insert?

To install a HELI-COIL tanged insert, drill the hole to the specified size, tap it using the correct STI tap (1/4"-28 for this insert), then use a HELI-COIL installation tool to wind the insert into the tapped hole. After installation, break off the tang with a punch. Always follow the manufacturer's instructions for best results.

Used in

Common applications for HELI-COIL
Aerospace engine repair — HELI-COIL STI taps for M12x1.75 metric threads in aluminum alloy components
Automotive transmission rebuild — HELI-COIL STI taps for 7/16-14 UNC threads in cast iron housings
Industrial pump maintenance — HELI-COIL STI taps for #10-32 UNF threads in stainless steel pump bodies
Hydraulic cylinder repair — HELI-COIL STI taps for M6x1 metric threads in steel cylinder heads
General manufacturing — HELI-COIL STI taps for 9/16-18 UNF threads in machinery base plates

HELI-COIL Products

3G Electric supplies HELI-COIL screw-locking tanged helical inserts. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

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HELI-COIL Helical Insert: Tanged Tang Style, Screw-Locking, 5/16"-18 Thread Size, Plain, 100 PK (MPN A3585-5EN469). Key specifications — Material Grade/Class: Nitronic 60; Thread Direction: Right Hand; STI Tap Size: 5/16"-18; Compatible Material: Metal; System of Measurement: Inch; Brand: HELI-COIL; Tensile Strength: 200,000 psi; Thread Type: Coarse.
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HELI-COIL Helical Insert: Tanged Tang Style, Screw-Locking, #6-32 Thread Size, 1,000 PK (MPN 3585-06CNW138S). Key specifications — Material Grade/Class: 18-8; Thread Direction: Right Hand; STI Tap Size: #6-32; Compatible Material: Metal; System of Measurement: Inch; Brand: HELI-COIL; Tensile Strength: 200,000 to 250,000 psi; Thread Type: Coarse.
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HELI-COIL Helical Insert: Tanged Tang Style, Screw-Locking, #6-32 Thread Size, 1,000 PK (MPN 3585-06CNW138S). Key specifications — Material Grade/Class: 18-8; Thread Direction: Right Hand; STI Tap Size: #6-32; Compatible Material: Metal; System of Measurement: Inch; Brand: HELI-COIL; Tensile Strength: 200,000 to 250,000 psi; Thread Type: Coarse.
HELI-COIL Helical Insert: Tanged Tang Style, Screw-Locking, #6-32 Thread Size, Plain, Plain, 100 PK (MPN A3585-06EN207). Key specifications — Material Grade/Class: Nitronic 60; Thread Direction: Right Hand; STI Tap Size: #6-32; Compatible Material: Metal; System of Measurement: Inch; Brand: HELI-COIL; Tensile Strength: 200,000 psi; Thread Type: Coarse.
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HELI-COIL Helical Insert: Tanged Tang Style, Screw-Locking, #6-32 Thread Size, Plain, Plain, 100 PK (MPN A3585-06EN207). Key specifications — Material Grade/Class: Nitronic 60; Thread Direction: Right Hand; STI Tap Size: #6-32; Compatible Material: Metal; System of Measurement: Inch; Brand: HELI-COIL; Tensile Strength: 200,000 psi; Thread Type: Coarse.
HELI-COIL Helical Insert: Tanged Tang Style, Screw-Locking, #8-32 Thread Size, 100 PK (MPN A3585-2CNW164). Key specifications — Material Grade/Class: 18-8; Thread Direction: Right Hand; STI Tap Size: #8-32; Compatible Material: Metal; System of Measurement: Inch; Brand: HELI-COIL; Tensile Strength: 200,000 to 250,000 psi; Thread Type: Coarse.
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HELI-COIL Helical Insert: Tanged Tang Style, Screw-Locking, #8-32 Thread Size, 100 PK (MPN A3585-2CNW164). Key specifications — Material Grade/Class: 18-8; Thread Direction: Right Hand; STI Tap Size: #8-32; Compatible Material: Metal; System of Measurement: Inch; Brand: HELI-COIL; Tensile Strength: 200,000 to 250,000 psi; Thread Type: Coarse.
HELI-COIL Helical Insert: Tanged Tang Style, Screw-Locking, #10-32 Thread Size, Plain, Plain, 100 PK (MPN A3591-3EN380). Key specifications — Material Grade/Class: Nitronic 60; Thread Direction: Right Hand; STI Tap Size: #10-32; Compatible Material: Metal; System of Measurement: Inch; Brand: HELI-COIL; Tensile Strength: 200,000 psi; Thread Type: Fine.
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HELI-COIL Helical Insert: Tanged Tang Style, Screw-Locking, 1 1/8"-7 Thread Size, Stainless Steel (MPN 3585-18CN1125). Key specifications — Material Grade/Class: 18-8; Thread Direction: Right Hand; STI Tap Size: 1-1/8"-7; Compatible Material: Metal; System of Measurement: Inch; Brand: HELI-COIL; Tensile Strength: 200,000 to 250,000 psi; Thread Type: Coarse.
HELI-COIL Helical Insert: Tanged Tang Style, Screw-Locking, 1/4"-28 Thread Size, Plain, 100 PK (MPN A3591-4CN250). Key specifications — Material Grade/Class: 18-8; Thread Direction: Right Hand; STI Tap Size: 1/4"-28; Compatible Material: Metal; System of Measurement: Inch; Brand: HELI-COIL; Tensile Strength: 200,000 to 250,000 psi; Thread Type: Fine.
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HELI-COIL Helical Insert: Tanged Tang Style, Screw-Locking, 1/4"-28 Thread Size, Plain, 100 PK (MPN A3591-4CN250). Key specifications — Material Grade/Class: 18-8; Thread Direction: Right Hand; STI Tap Size: 1/4"-28; Compatible Material: Metal; System of Measurement: Inch; Brand: HELI-COIL; Tensile Strength: 200,000 to 250,000 psi; Thread Type: Fine.
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