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HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, 1/4"-28 Thread Size - Free-Running Tangless Helical Inserts
HELI-COILFree-Running Tangless Helical Inserts

HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, 1/4"-28 Thread Size

The HELI-COIL Helical Insert (Tangless Tang Style) is a free-running, plain finish insert in a 100-piece pack, designed for 1/4"-28 fine threads in metal. Made from 18-8 material with a tensile strength of 200,000 to…

SKU 3G-OTH-527350

Brand
HELI-COIL
Item
Helical Insert: Tangless Tang Style, Free-Running, 1/4"-28 Thread Size
Category
Free-Running Tangless Helical Inserts
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Technical Specifications

HELI-COIL
Manufacturer Part Number
AT1191-4C500
Type
Free-Running, 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
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HELI-COIL Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The HELI-COIL Helical Insert (Tangless Tang Style) is a free-running, plain finish insert in a 100-piece pack, designed for 1/4"-28 fine threads in metal. Made from 18-8 material with a tensile strength of 200,000 to 250,000 psi, it uses a right-hand thread direction and requires an STI tap size of 1/4"-28. This inch-system insert is compatible with metal substrates and is manufactured under part number AT1191-4C500.

Frequently Asked Questions

What is a HELI-COIL Tangless helical insert used for?

A HELI-COIL Tangless helical insert repairs or reinforces internal threads in metal. The tangless design eliminates the need to break off a tang after installation, saving time. It is ideal for restoring stripped threads in automotive, aerospace, and industrial equipment, providing strong, wear-resistant threads in aluminum or steel.

What are the specifications of the HELI-COIL AT1191-4C500 insert?

The HELI-COIL AT1191-4C500 is a free-running, plain finish insert in a 100-piece pack. It has a 1/4\"-28 fine thread size, right-hand thread direction, and requires an STI tap size of 1/4\"-28. Made from 18-8 material, it offers a tensile strength of 200,000 to 250,000 psi and is compatible with metal substrates.

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 AT1191-4C500 and other HELI-COIL products to your facility. Contact us for a quote and lead time on this 100-piece pack of tangless inserts.

How to install a HELI-COIL Tangless insert?

To install a HELI-COIL Tangless insert, drill out the damaged thread to the specified size, then tap the hole using the correct STI tap (1/4\"-28 for this insert). Use a tangless installation tool to wind the insert into the tapped hole until it sits slightly below the surface. No tang removal is needed.

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 free-running tangless 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: Tangless Tang Style, Free-Running, #10-24 Thread Size, Plain, 100 PK (MPN AT1185-3C380). Key specifications — Material Grade/Class: 18-8; Thread Direction: Right Hand; STI Tap Size: #10-24; 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: Tangless Tang Style, Free-Running, #10-24 Thread Size, Plain, 100 PK (MPN AT1185-3C380). Key specifications — Material Grade/Class: 18-8; Thread Direction: Right Hand; STI Tap Size: #10-24; 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: Tangless Tang Style, Free-Running, #2-56 Thread Size, Plain, Plain, 100 PK (MPN AT1185-02C086). Key specifications — Material Grade/Class: 18-8; Thread Direction: Right Hand; STI Tap Size: #2-56; 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: Tangless Tang Style, Free-Running, 1/4"-20 Thread Size, Plain, 1,000 PK (MPN T1185-4C250S). Key specifications — Material Grade/Class: 18-8; Thread Direction: Right Hand; STI Tap Size: 1/4"-20; 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: Tangless Tang Style, Free-Running, #8-32 Thread Size, Plain, 1,000 PK (MPN T1185-2C164S). 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: Tangless Tang Style, Free-Running, #8-32 Thread Size, Plain, 1,000 PK (MPN T1185-2C164S). 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: Tangless Tang Style, Free-Running, 1/4"-28 Thread Size, Plain, 100 PK (MPN AT1191-4C375). Key specifications — Material Grade/Class: 18-8; Thread Direction: Right Hand; STI Tap Size: #10-32; 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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