Send a part number, a photo, or a whole BOM — we supply it and stand behind it. Worldwide shipping to 80+ countries.

3G Electric
RFQ CartGet a QuoteSign inSign up
HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, 1/4"-20 Thread Size - Free-Running Tangless Helical Inserts
HELI-COILFree-Running Tangless Helical Inserts

HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, 1/4"-20 Thread Size

The HELI-COIL Helical Insert (Tangless Tang Style) is a free-running, plain finish insert in a 100-piece pack, featuring a 1/4"-20 coarse thread size and right-hand thread direction. Made from 18-8 material grade, it…

SKU 3G-OTH-527328

Brand
HELI-COIL
Item
Helical Insert: Tangless Tang Style, Free-Running, 1/4"-20 Thread Size
Category
Free-Running Tangless Helical Inserts
Available to Order
Trade pricing by quote — replies within 24h
Qty
WhatsApp an engineer
No account needed — your quote request goes straight to our engineers. A free account lets you track quotes and re-order faster.
Worldwide Shipping
Air & sea freight
Datasheet on Request
Technical specs
1-Day Quote
Replies within 24h

Technical Specifications

HELI-COIL
Manufacturer Part Number
AT1185-4C375
Type
Free-Running, Plain, 100 PK
Tensile Strength
200,000 to 250,000 psi
Finish Type
Plain
Thread Size
1/4"-20
Thread Type
Coarse
STI Tap Size
1/4"-20
Thread Direction
Right Hand
Compatible Material
Metal
Material Grade/Class
18-8
System of Measurement
Inch
View Full Spec Sheet

Technical Documents

No technical documents available for this product.
Request documentation →
Not sure this is the right part? Get a recommendation.

Need installation or engineering help?

Installation, commissioning, maintenance plans, system design, and bundled product + service quotes — one team handles the full scope.
Talk to an engineer

Ask a question

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, featuring a 1/4"-20 coarse thread size and right-hand thread direction. Made from 18-8 material grade, it offers a tensile strength of 200,000 to 250,000 psi and is compatible with metal substrates, requiring an STI tap size of 1/4"-20 for installation.

Frequently Asked Questions

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

A HELI-COIL Tangless helical insert repairs or reinforces tapped threads in metal. The tangless design eliminates the need to break off a tang after installation, saving time. It is ideal for automotive, aerospace, and industrial applications where strong, wear-resistant threads are required.

What are the specifications of the HELI-COIL AT1185-4C375 insert?

This HELI-COIL insert has a 1/4"-20 coarse thread size, right-hand direction, and a tensile strength of 200,000 to 250,000 psi. It is made from 18-8 stainless steel with a plain finish, comes in a 100-piece pack, and requires an STI tap size of 1/4"-20 for installation.

Where to buy HELI-COIL helical inserts worldwide?

3G Electric supplies HELI-COIL helical inserts worldwide. As a global industrial sourcing partner, we handle logistics, customs clearance, and delivery to your facility. Contact us for pricing and lead time on the AT1185-4C375 or other HELI-COIL part numbers.

How to install a tangless helical insert?

To install a tangless helical insert, drill the hole to the specified size, tap it using the correct STI tap (1/4"-20 for this insert), then use a tangless installation tool to wind the insert into the tapped hole. No tang removal step is needed, simplifying the process.

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.

You might also need

Burners & Combustion →Pumps & Compressors →Spare Parts →All Products →

More from HELI-COIL

View all HELI-COIL parts →
HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, #6-32 Thread Size, Plain, 1,000 PK (MPN T1185-06C276S). 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
HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, #6-32 Thread Size, Plain, 1,000 PK (MPN T1185-06C276S). 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: Tangless Tang Style, Free-Running, #2-56 Thread Size, Plain, Plain, 100 PK (MPN AT1185-02C172). 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.
HELI-COIL
HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, #2-56 Thread Size, Plain, Plain, 100 PK (MPN AT1185-02C172). 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.
HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, 1/4"-28 Thread Size, Plain, 1,000 PK (MPN T1191-4C250S). 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.
HELI-COIL
HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, 1/4"-28 Thread Size, Plain, 1,000 PK (MPN T1191-4C250S). 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.
HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, 1/4"-20 Thread Size, Plain, 1,000 PK (MPN T1185-4C375S). 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.
HELI-COIL
HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, 1/4"-20 Thread Size, Plain, 1,000 PK (MPN T1185-4C375S). 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.
HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, 1/4"-20 Thread Size, Plain, 100 PK (MPN AT1185-4C250). 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.
HELI-COIL
HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, 1/4"-20 Thread Size, Plain, 100 PK (MPN AT1185-4C250). 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.
HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, #8-32 Thread Size, Plain, Plain, 100 PK (MPN AT1185-2C246). 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
HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, #8-32 Thread Size, Plain, Plain, 100 PK (MPN AT1185-2C246). 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, #8-32 Thread Size, Plain, 1,000 PK (MPN T1185-2C328S). 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
HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, #8-32 Thread Size, Plain, 1,000 PK (MPN T1185-2C328S). 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, #4-40 Thread Size, Plain, 1,000 PK (MPN T1185-04C224S). Key specifications — Material Grade/Class: 18-8; Thread Direction: Right Hand; STI Tap Size: #4-40; Compatible Material: Metal; System of Measurement: Inch; Brand: HELI-COIL; Tensile Strength: 200,000 to 250,000 psi; Thread Type: Coarse.
HELI-COIL
HELI-COIL Helical Insert: Tangless Tang Style, Free-Running, #4-40 Thread Size, Plain, 1,000 PK (MPN T1185-04C224S). Key specifications — Material Grade/Class: 18-8; Thread Direction: Right Hand; STI Tap Size: #4-40; Compatible Material: Metal; System of Measurement: Inch; Brand: HELI-COIL; Tensile Strength: 200,000 to 250,000 psi; Thread Type: Coarse.