Send a part number, a photo, or a whole BOM — we supply it and stand behind it. EXW Singapore — collect from our office.

3G Electric
HELI-COIL Free-Running Tangless Helical Insert, 1/4"-28, Plain, 100 PK - Free-Running Tangless Helical Inserts
HELI-COILFree-Running Tangless Helical Inserts

HELI-COIL Free-Running Tangless Helical Insert, 1/4"-28, Plain, 100 PK

The HELI-COIL Helical Insert (Tangless Tang Style) is a free-running, plain finish insert with a 1/4"-28 fine thread, right-hand direction, and an STI tap size of #10-32. Made from 18-8 material grade/class, it…

SKU 3G-OTH-527330

Also listed as: AT11914C250 · AT1191 4C250

Brand
HELI-COIL
Item
Free-Running Tangless Helical Insert, 1/4"-28, Plain, 100 PK
Part Number
AT1191-4C250
Category
Free-Running Tangless Helical Inserts
Available to Order
Trade pricing by quote — replies within 24h
Qty
WhatsApp an engineerMessage via Telegram
No account needed — your quote request goes straight to our engineers. A free account lets you track quotes and re-order faster.
EXW Singapore
Collect or forward from our office
Datasheet on Request
Technical specs
1-Day Quote
Replies within 24h

Local availability & support — Singapore

Local office
20 Woodlands Link #09-05, Singapore 738733
Phone
+65 8878 8355
Payment
Invoicing in SGD. PayNow, bank transfer, and corporate PO accepted.

Technical Specifications

HELI-COIL
Manufacturer Part Number
AT1191-4C250
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
#10-32
Thread Direction
Right Hand
Compatible Material
Metal
Material Grade/Class
18-8
System of Measurement
Inch

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 with a 1/4"-28 fine thread, right-hand direction, and an STI tap size of #10-32. Made from 18-8 material grade/class, it offers a tensile strength of 200,000 to 250,000 psi and is compatible with metal substrates. Supplied in a 100-pack (SKU AT1191-4C250, MPN AT1191-4C250), this inch-system insert is designed for thread repair and reinforcement in metal applications.

Frequently Asked Questions

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

A HELI-COIL Tangless helical insert repairs or reinforces stripped or damaged internal threads in metal components. The tangless design eliminates the need for a break-off tang, simplifying installation. It is commonly used in automotive, aerospace, and industrial maintenance applications to restore thread integrity without replacing the parent material.

What are the specifications of the HELI-COIL AT1191-4C250 insert?

The HELI-COIL AT1191-4C250 is a free-running, plain finish insert with a 1/4\"-28 fine thread, right-hand direction, and STI tap size #10-32. Made from 18-8 material, it offers a tensile strength of 200,000 to 250,000 psi. It is supplied in a 100-pack and is compatible with metal substrates.

Where to buy HELI-COIL helical inserts in worldwide?

3G Electric supplies HELI-COIL helical inserts worldwide. As a global industrial solutions provider, we handle full logistics, customs clearance, and delivery to your location. Contact us for pricing and lead time on the AT1191-4C250 or other HELI-COIL part numbers. We source genuine industrial equipment across 14 departments.

How to install a tangless helical insert?

To install a tangless helical insert, drill the hole to the specified STI tap size (#10-32 for this insert), tap the hole with the corresponding STI tap, then use a tangless installation tool to wind the insert into the threaded hole. No break-off tang removal is needed. Follow the manufacturer's instructions for proper depth and alignment.

Used in

Common applications for HELI-COIL
Aerospace — Tangless screw-locking HELI-COIL inserts in 18-8 stainless steel for vibration-resistant threaded joints in airframe and engine components.
Automotive — Free-running tanged HELI-COIL inserts in metric sizes for repairing stripped threads in aluminum engine blocks and transmission housings.
Industrial machinery — STI taps and prewinder installation tools for on-site repair of threaded holes in cast iron and steel machine frames.
Oil and gas — Nitronic 60 HELI-COIL inserts for galling resistance in stainless steel valve bodies and pump housings exposed to corrosive media.
MRO and maintenance — HELI-COIL thread repair kits containing inserts, drill, tap, and installation tool for restoring damaged threads without replacing the parent component.
Electrical equipment — Screw-locking tangless HELI-COIL inserts for securing fasteners in metal enclosures and control panels subject to vibration.
Not sure this is the right part? Photo-identify it→

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 →

Customer reviews

No reviews yet — be the first

Questions & answers

No questions yet — ask us the first