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OSG 3/8"-16 UNC Spiral-Flute Extension Tap - Spiral-Flute Extension Taps
OSGSpiral-Flute Extension Taps

OSG 3/8"-16 UNC Spiral-Flute Extension Tap

The OSG Extension Tap (MPN 1298700) is a 3/8"-16 UNC spiral-flute extension tap, featuring a bottoming chamfer and three flutes in high-speed steel with an H3 / 2B-3B tolerance class. 3G Electric interprets demand…

SKU 3G-OTH-310982

Brand
OSG
Item
3/8"-16 UNC Spiral-Flute Extension Tap
Part Number
1298700
Category
Spiral-Flute Extension Taps
Available to Order
Also known as:1298700OSG
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Technical Specifications

OSG
Manufacturer Part Number
1298700
Type
H3 / 2B-3B, Bottoming Chamfer, High Speed Steel
Flute
3

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OSG Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The OSG Extension Tap (MPN 1298700) is a 3/8"-16 UNC spiral-flute extension tap, featuring a bottoming chamfer and three flutes in high-speed steel with an H3 / 2B-3B tolerance class. 3G Electric interprets demand and delivers this genuine industrial cutting tool across 14 departments, with specialist depth in machining and controls to support your sourcing needs.

Frequently Asked Questions

What is an OSG extension tap used for?

An OSG extension tap is used to cut internal threads in hard-to-reach or deep-hole applications. The 3/8"-16 UNC bottoming chamfer design allows threading close to the bottom of a blind hole, while the 3-flute spiral-flute geometry aids chip evacuation in ferrous and non-ferrous materials.

What are the specifications of the OSG 1298700 extension tap?

The OSG 1298700 is a 3/8"-16 UNC extension tap with H3 / 2B-3B tolerance, bottoming chamfer, 3 flutes, and high-speed steel construction. It is designed for through or blind hole threading and is suitable for general machining applications across multiple industries.

Where to buy OSG extension taps worldwide?

3G Electric supplies OSG extension taps like the 1298700 to customers worldwide. We handle full logistics, customs clearance, and delivery to your facility. Contact us for pricing and lead time on this and other OSG tooling across our 14 industrial departments.

How to select the correct OSG extension tap for a job?

Select an OSG extension tap based on thread size (e.g., 3/8"-16 UNC), chamfer type (bottoming for blind holes), flute count (3 for general use), and material compatibility. High-speed steel suits most ferrous metals. Confirm tolerance class (H3 / 2B-3B) matches your thread fit requirement.

Used in

Common applications for OSG
Aerospace — OSG STI taps for installing helical wire thread inserts in aluminum components
Automotive — OSG spiral-point taps for through-hole threading in engine blocks and transmission cases
General machining — OSG spiral-flute taps for blind-hole threading in steel and stainless steel parts
Heavy equipment repair — OSG thread-forming taps for creating threads in ductile iron and steel castings
Precision manufacturing — OSG solid carbide chucking reamers for finishing holes in hydraulic manifolds
Die and mold — OSG coolant-through solid carbide drills for deep-hole drilling in tool steels
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OSG Products

3G Electric supplies OSG spiral-flute extension taps. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

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