OSG Extension Tap: 1/4"-20 UNC, H3 / 2B-3B, 3 Flute, Bottoming Chamfer
The OSG Extension Tap (MPN 1297900) is a 1/4"-20 UNC spiral-flute extension tap with a bottoming chamfer, made from high-speed steel. It features an H3 / 2B-3B tolerance class and a 3-flute design, suitable for…
SKU 3G-OTH-310962
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Product Description
The OSG Extension Tap (MPN 1297900) is a 1/4"-20 UNC spiral-flute extension tap with a bottoming chamfer, made from high-speed steel. It features an H3 / 2B-3B tolerance class and a 3-flute design, suitable for threading applications requiring extended reach.
Frequently Asked Questions
What is the OSG Extension Tap 1/4"-20 UNC used for?
The OSG Extension Tap is used for threading blind or deep holes in metal parts where standard taps cannot reach. Its extended length and 3-flute spiral design clear chips efficiently, making it ideal for automotive, aerospace, and general machining applications requiring precise UNC threads.
What are the specifications of the OSG Extension Tap 1/4"-20 UNC?
This OSG tap has a 1/4"-20 UNC thread size, H3 / 2B-3B tolerance, bottoming chamfer, 3 flutes, and is made of high-speed steel. The manufacturer part number is 1297900. It is designed for threading blind holes to the bottom with a spiral-flute geometry for chip evacuation.
Where to buy the OSG Extension Tap 1/4"-20 UNC worldwide?
You can source the OSG Extension Tap 1/4"-20 UNC worldwide through 3G Electric. As a global industrial equipment distributor since 1990, we handle full logistics, customs clearance, and delivery to your location. Contact us for availability and lead time.
How to select the correct OSG Extension Tap for UNC threads?
Select the tap based on thread size (e.g., 1/4"-20 UNC), chamfer type (bottoming for blind holes), flute count (3-flute for balance of strength and chip removal), and material (high-speed steel for general use). Ensure the H3 tolerance matches your required thread class (2B-3B). OSG taps are precision-ground for consistent performance.
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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.
