HELI-COILGeneral Purpose STI Taps

HELI-COIL General Purpose STI Tap, 1 1/4"-7 UNC, H4 / 3B, Plug Chamfer, 4 Flutes

SKU 3G-OTH-262032

Also listed as: 818720 · 8187 20

Brand

HELI-COIL

Item

General Purpose STI Tap, 1 1/4"-7 UNC, H4 / 3B, Plug Chamfer, 4 Flutes

Part Number

8187-20

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

8187-20 

Type

H4 / 3B, Plug Chamfer 

Flute

4

UNC

1 1/4"-7 

Technical Documents

No technical documents available for this product.

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HELI-COIL Products

3G Electric (S) Pte. Ltd. — Singapore

Product Description

The HELI-COIL Screw Thread Insert STI Tap is a general-purpose tap with a straight flute design, specified as 1 1/4"-7 UNC, H4 / 3B tolerance, 4 flutes, and a plug chamfer (MPN 8187-20). This tool is engineered for installing HELI-COIL screw thread inserts, ensuring accurate thread formation in industrial applications.

Frequently Asked Questions

What is a HELI-COIL STI tap used for?

A HELI-COIL STI tap cuts threads for installing screw thread inserts in metal parts. It is used in automotive, aerospace, and industrial maintenance to repair stripped threads or add durable threads in softer materials like aluminum.

What are the specifications of the HELI-COIL STI tap 8187-20?

This HELI-COIL STI tap has a 1 1/4"-7 UNC thread, H4 / 3B tolerance, 4 flutes, and a plug chamfer. It is a general-purpose tap designed for straight-flute thread cutting before inserting HELI-COIL inserts.

Where to buy HELI-COIL STI taps worldwide?

3G Electric supplies HELI-COIL STI taps worldwide. We handle full logistics and customs clearance to deliver this 8187-20 tap to your facility. Contact us for pricing and lead time on this and other industrial tooling.

How to select the correct STI tap for a thread repair?

Match the STI tap to the insert size and thread class. For a 1 1/4"-7 UNC insert, use a tap with H4 / 3B tolerance and plug chamfer. Always verify the tap matches the insert manufacturer's recommendations for proper thread engagement.

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.

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HELI-COIL Products

3G Electric supplies HELI-COIL general purpose sti taps. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

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