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

3G Electric
HELI-COIL Screw-Locking Tanged Helical Insert, 3/4"-16, 1 1/8 in L, 18-8 - Screw-Locking Tanged Helical Inserts
HELI-COILScrew-Locking Tanged Helical Inserts

HELI-COIL Screw-Locking Tanged Helical Insert, 3/4"-16, 1 1/8 in L, 18-8

The HELI-COIL Helical Insert is a tanged tang style, screw-locking insert with a 3/4"-16 fine thread, 1 1/8 in overall length, and a tensile strength of 200,000 to 250,000 psi. Made from 18-8 material grade/class, it…

SKU 3G-OTH-528904

Also listed as: 359112CN1125 · 3591 12CN1125

Brand
HELI-COIL
Item
Screw-Locking Tanged Helical Insert, 3/4"-16, 1 1/8 in L, 18-8
Part Number
3591-12CN1125
Category
Screw-Locking Tanged 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.
Worldwide Shipping
Air & sea freight
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
Delivery
Same-day or next-business-day delivery within Singapore for in-stock items; 7–14 days for factory-order parts from Europe.
Payment
Invoicing in SGD. PayNow, bank transfer, and corporate PO accepted.
Ships to
Singapore

Technical Specifications

HELI-COIL
Manufacturer Part Number
3591-12CN1125
Type
Screw-Locking
Overall Lg
1 1/8 in
Tensile Strength
200,000 to 250,000 psi
Finish Type
Plain
Thread Size
3/4"-16
Thread Type
Fine
STI Tap Size
3/4"-16
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 is a tanged tang style, screw-locking insert with a 3/4"-16 fine thread, 1 1/8 in overall length, and a tensile strength of 200,000 to 250,000 psi. Made from 18-8 material grade/class, it is compatible with metal and uses a right-hand thread direction. This inch-system insert requires an STI tap size of 3/4"-16 and has a plain finish.

Frequently Asked Questions

What is a HELI-COIL helical insert used for?

A HELI-COIL helical insert repairs or reinforces threads in metal components. This screw-locking, tanged tang style insert provides strong, wear-resistant threads in applications like automotive, aerospace, and industrial machinery where original threads are stripped or need added strength.

What are the specifications of the HELI-COIL 3591-12CN1125 insert?

This HELI-COIL insert has a 3/4"-16 fine thread, 1 1/8 in overall length, and tensile strength of 200,000 to 250,000 psi. It is made from 18-8 material, uses a right-hand thread direction, requires an STI tap size of 3/4"-16, and has a plain finish.

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 this 3/4"-16 screw-locking insert to your facility. Contact us for pricing and lead time on the 3591-12CN1125.

How to install a HELI-COIL tanged tang insert?

To install a HELI-COIL tanged tang insert, drill out the damaged thread to the specified size, tap the hole using the correct STI tap (3/4"-16 for this insert), then wind the insert into the tapped hole using a tang drive tool. After installation, break off the tang for a flush finish.

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
Not sure this is the right part? Photo-identify it

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.

You might also need

Burners & Combustion Pumps & Compressors Spare Parts All Products

More from HELI-COIL

View all HELI-COIL parts
Screw-locking tanged helical insert for repairing or reinforcing tapped threads in metal. Made of 18-8 stainless steel with dry film lubricant finish. #2-56 coarse thread, right-hand direction. Tensile strength 200,000 to 250,000 psi. Pack of 100
HELI-COIL
Screw-locking tanged helical insert for repairing or reinforcing tapped threads in metal. Made of 18-8 stainless steel with dry film lubricant finish. #2-56 coarse thread, right-hand direction. Tensile strength 200,000 to 250,000 psi. Pack of 100
Screw-locking tanged helical insert for repairing or strengthening threaded holes in metal. Features 18-8 stainless steel construction with 1/4"-28 fine thread and tensile strength of 200,000 to 250,000 psi. Plain finish. Pack of 100
HELI-COIL
Screw-locking tanged helical insert for repairing or strengthening threaded holes in metal. Features 18-8 stainless steel construction with 1/4"-28 fine thread and tensile strength of 200,000 to 250,000 psi. Plain finish. Pack of 100

Customer reviews

No reviews yet — be the first

Questions & answers

No questions yet — ask us the first