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OSG Screw Thread Insert STI Tap: Straight Fute, 3/4"-16 UNF, H4 / 2B-3B, 4 Flute - General Purpose STI Taps
OSGGeneral Purpose STI Taps

OSG Screw Thread Insert STI Tap: Straight Fute, 3/4"-16 UNF, H4 / 2B-3B, 4 Flute

The OSG Screw Thread Insert STI Tap (SKU 33ZK57) is a general-purpose STI tap with a straight flute design, sized 3/4"-16 UNF. It features a bottoming chamfer, 4 flutes, and an H4 / 2B-3B tolerance class (MPN 12603800).

SKU 3G-OTH-262102

Brand
OSG
Item
Screw Thread Insert STI Tap: Straight Fute, 3/4"-16 UNF, H4 / 2B-3B, 4 Flute
Category
General Purpose STI Taps
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Technical Specifications

OSG
Manufacturer Part Number
12603800
Type
H4 / 2B-3B, Bottoming Chamfer
Flute
4
UNF
3/4"-16
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OSG Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The OSG Screw Thread Insert STI Tap (SKU 33ZK57) is a general-purpose STI tap with a straight flute design, sized 3/4"-16 UNF. It features a bottoming chamfer, 4 flutes, and an H4 / 2B-3B tolerance class (MPN 12603800).

Frequently Asked Questions

What is an OSG Screw Thread Insert STI Tap used for?

An OSG STI tap cuts internal threads in a pre-drilled hole to accept a helical wire thread insert. It is used in industrial maintenance and production to repair or reinforce stripped threads in metals and plastics, restoring fastener integrity without replacing the parent component.

What are the specifications of the OSG 12603800 STI Tap?

The OSG 12603800 is a straight flute STI tap with 3/4"-16 UNF thread, H4 / 2B-3B tolerance, 4 flutes, and a bottoming chamfer. It is designed for general-purpose thread insert installation. The H4 ground thread form ensures precise fit for 2B-3B class internal threads.

Where to buy OSG STI Taps worldwide?

3G Electric supplies OSG STI taps like the 12603800 to customers worldwide. We handle full logistics, customs clearance, and delivery to your facility. Contact us for a quote on this or any other OSG cutting tool — we source genuine industrial equipment across 14 departments.

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

Select an STI tap that matches the original thread size and pitch — for example, 3/4"-16 UNF. Use a bottoming chamfer tap like this OSG for blind holes, and a plug chamfer for through holes. Always drill the recommended STI tap drill diameter before tapping.

Used in

Common applications for OSG
Automotive engine block production — OSG micro drill bits for oil gallery and coolant passage drilling in cast iron
Medical device manufacturing — OSG micro drill bits for drilling bone screw pilot holes in stainless steel implants
Aerospace component machining — OSG micro drill bits for fastener holes in titanium alloy structural parts
Mold and die making — OSG micro drill bits for cooling channel drilling in hardened tool steel (HRC 45-50)
Electronics enclosure fabrication — OSG micro drill bits for precision holes in aluminum alloy housings (with appropriate coating selection)
General engineering job shops — OSG micro drill bits for small-diameter hole drilling in mild steel and alloy steel parts

OSG Products

3G Electric supplies OSG 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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