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

HELI-COIL Screw-Locking Tanged Helical Insert - Screw-Locking Tanged Helical Inserts
HELI-COILScrew-Locking Tanged Helical Inserts

HELI-COIL Screw-Locking Tanged Helical Insert

The HELI-COIL Helical Insert is a tanged tang-style, screw-locking insert made from 18-8 stainless steel with a plain finish. It features a 1 1/4"-7 coarse right-hand thread, an STI tap size of 1-1/8"-7, and a…

SKU 3G-OTH-529001

Also listed as: 358520CN1250 · 3585 20CN1250

Brand
HELI-COIL
Item
Screw-Locking Tanged Helical Insert
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
3585-20CN1250
Type
Screw-Locking, Stainless Steel
Tensile Strength
200,000 to 250,000 psi
Finish Type
Plain
Thread Size
1 1/4"-7
Thread Type
Coarse
STI Tap Size
1-1/8"-7
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 made from 18-8 stainless steel with a plain finish. It features a 1 1/4"-7 coarse right-hand thread, an STI tap size of 1-1/8"-7, and a tensile strength of 200,000 to 250,000 psi, designed for use with metal materials.

Frequently Asked Questions

What is a HELI-COIL helical insert used for?

A HELI-COIL helical insert repairs or reinforces tapped threads in metal. This screw-locking tanged tang style, with 1 1/4"-7 coarse thread, provides strong, wear-resistant threads in applications like engine blocks or industrial equipment, preventing thread stripping under high loads.

What are the specifications of the HELI-COIL 3585-20CN1250?

This HELI-COIL insert has a 1 1/4"-7 coarse right-hand thread, STI tap size 1-1/8"-7, and tensile strength 200,000 to 250,000 psi. It is made from 18-8 stainless steel with a plain finish, designed for metal materials. The manufacturer part number is 3585-20CN1250.

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 1 1/4"-7 screw-locking insert to your facility. Contact us for availability and lead time on this part.

How to install a HELI-COIL tanged helical insert?

Installation requires drilling to the specified STI tap size (1-1/8"-7 for this insert), tapping the hole, then using a tang drive tool to insert the coil. After installation, break off the tang. Always follow HELI-COIL's generic instructions for proper thread engagement and torque.

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.

You might also need

Burners & Combustion Pumps & Compressors Spare Parts All Products

Compatible alternatives & equivalents

Cross-referenced by specification & description
Screw-locking tanged helical insert for repairing or reinforcing threaded holes in metal substrates. Features #10-32 fine right-hand threads, plain finish, and 18-8 stainless steel construction with tensile strength of 200,000 to 250,000 psi. Supplied in packs of 1,000
HELI-COIL
Screw-locking tanged helical insert for repairing or reinforcing threaded holes in metal substrates. Features #10-32 fine right-hand threads, plain finish, and 18-8 stainless steel construction with tensile strength of 200,000 to 250,000 psi. Supplied in packs of 1,000
Screw-locking tanged helical insert for repairing or reinforcing threads in metal substrates. M16-2.00 thread size, 18-8 material, plain finish, tensile strength 200,000 to 250,000 psi. Requires 16.5mm drill bit and STI tap M16-2.00. Right-hand thread, metric, 100 pieces per pack
HELI-COIL
Screw-locking tanged helical insert for repairing or reinforcing threads in metal substrates. M16-2.00 thread size, 18-8 material, plain finish, tensile strength 200,000 to 250,000 psi. Requires 16.5mm drill bit and STI tap M16-2.00. Right-hand thread, metric, 100 pieces per pack
Free-running tangless helical insert for thread repair and reinforcement in metal applications. Made of 18-8 stainless steel with a tensile strength of 200,000 to 250,000 psi. Features #2-56 coarse right-hand thread, plain finish, and requires STI tap size #2-56. Supplied in a 100-piece pack
HELI-COIL
Free-running tangless helical insert for thread repair and reinforcement in metal applications. Made of 18-8 stainless steel with a tensile strength of 200,000 to 250,000 psi. Features #2-56 coarse right-hand thread, plain finish, and requires STI tap size #2-56. Supplied in a 100-piece pack
HELI-COIL Screw Thread Insert STI Tap: Straight Fute, 1 1/4"-7 UNC, H4 / 3B, 4 Flute, Plug Chamfer (MPN 8187-20)
HELI-COIL
HELI-COIL Screw Thread Insert STI Tap: Straight Fute, 1 1/4"-7 UNC, H4 / 3B, 4 Flute, Plug Chamfer (MPN 8187-20)
HELI-COIL Screw Thread Insert STI Tap: Straight Fute, 7/16"-14 UNC, H3 / 3B, 4 Flute, Plug Chamfer (MPN 7CPB)
HELI-COIL
HELI-COIL Screw Thread Insert STI Tap: Straight Fute, 7/16"-14 UNC, H3 / 3B, 4 Flute, Plug Chamfer (MPN 7CPB)
Straight flute STI tap for cutting internal threads to accept HELI-COIL screw thread inserts. Features H3 / 3B tolerance, plug chamfer, and 4 flutes. Used for general-purpose thread repair or reinforcement in metal parts
HELI-COIL
Straight flute STI tap for cutting internal threads to accept HELI-COIL screw thread inserts. Features H3 / 3B tolerance, plug chamfer, and 4 flutes. Used for general-purpose thread repair or reinforcement in metal parts

More from HELI-COIL

View all HELI-COIL parts
Screw-locking tanged helical insert for repairing or reinforcing threads in metal components. Features #8-32 coarse thread, right-hand direction, 18-8 material, and tensile strength of 200,000 to 250,000 psi. Supplied in a 100-piece pack
HELI-COIL
Screw-locking tanged helical insert for repairing or reinforcing threads in metal components. Features #8-32 coarse thread, right-hand direction, 18-8 material, and tensile strength of 200,000 to 250,000 psi. Supplied in a 100-piece pack
Screw-locking tanged helical insert for repairing or reinforcing threads in metal. #4-40 thread size, coarse thread, right-hand direction. Made from 18-8 stainless steel with tensile strength 200,000 to 250,000 psi. Plain finish, 1,000 pieces per pack
HELI-COIL
Screw-locking tanged helical insert for repairing or reinforcing threads in metal. #4-40 thread size, coarse thread, right-hand direction. Made from 18-8 stainless steel with tensile strength 200,000 to 250,000 psi. Plain finish, 1,000 pieces per pack
Screw-locking tanged helical insert for repairing or reinforcing threads in metal components. Features #6-32 coarse thread, 18-8 stainless steel, plain finish, and tensile strength of 200,000 to 250,000 psi. Right-hand thread direction. Pack of 1,000
HELI-COIL
Screw-locking tanged helical insert for repairing or reinforcing threads in metal components. Features #6-32 coarse thread, 18-8 stainless steel, plain finish, and tensile strength of 200,000 to 250,000 psi. Right-hand thread direction. Pack of 1,000
Screw-locking tanged helical insert for repairing or reinforcing threads in metal components. Features 1/4"-28 fine thread, right-hand direction, and requires STI tap size 1/4"-28. Made from Nitronic 60 with tensile strength of 200,000 psi. Supplied in a 100-piece pack with plain finish
HELI-COIL
Screw-locking tanged helical insert for repairing or reinforcing threads in metal components. Features 1/4"-28 fine thread, right-hand direction, and requires STI tap size 1/4"-28. Made from Nitronic 60 with tensile strength of 200,000 psi. Supplied in a 100-piece pack with plain finish
18-8 stainless steel helical insert with screw-locking feature for right-hand threads. Requires 6.25mm drill bit and M6-1.00 STI tap. Tensile strength 200,000 to 250,000 psi. Used to repair or reinforce threads in metal components
HELI-COIL
18-8 stainless steel helical insert with screw-locking feature for right-hand threads. Requires 6.25mm drill bit and M6-1.00 STI tap. Tensile strength 200,000 to 250,000 psi. Used to repair or reinforce threads in metal components
Screw-locking tanged helical insert for repairing or reinforcing threads in metal. Features #10-32 fine thread, right-hand direction, 18-8 stainless steel construction with dry film lubricant finish. Tensile strength 200,000 to 250,000 psi. Supplied in a 1,000-piece pack
HELI-COIL
Screw-locking tanged helical insert for repairing or reinforcing threads in metal. Features #10-32 fine thread, right-hand direction, 18-8 stainless steel construction with dry film lubricant finish. Tensile strength 200,000 to 250,000 psi. Supplied in a 1,000-piece pack
Screw-locking tanged helical insert for repairing or reinforcing threads in metal substrates. #10-24 coarse thread, right-hand direction, 18-8 stainless steel with tensile strength 200,000-250,000 psi. Plain finish, 1,000 pieces per pack
HELI-COIL
Screw-locking tanged helical insert for repairing or reinforcing threads in metal substrates. #10-24 coarse thread, right-hand direction, 18-8 stainless steel with tensile strength 200,000-250,000 psi. Plain finish, 1,000 pieces per pack
Screw-locking tanged helical insert for repairing or reinforcing threads in metal. Features 5/16"-18 coarse right-hand thread, 18-8 stainless steel construction, and tensile strength of 200,000 to 250,000 psi. Plain finish, supplied in a 500-piece pack. Requires 5/16"-18 STI tap for installation
HELI-COIL
Screw-locking tanged helical insert for repairing or reinforcing threads in metal. Features 5/16"-18 coarse right-hand thread, 18-8 stainless steel construction, and tensile strength of 200,000 to 250,000 psi. Plain finish, supplied in a 500-piece pack. Requires 5/16"-18 STI tap for installation