OSG Extension Tap: 1/4"-28 UNF, H3 / 2B-3B, 3 Flute, Plug Chamfer
The OSG Extension Tap (MPN 1298200) is a 1/4"-28 UNF spiral-flute extension tap, type H3 / 2B-3B with a plug chamfer, made of high-speed steel and featuring 3 flutes. 3G Electric sources this precision threading tool…
SKU 3G-OTH-310984
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Product Description
The OSG Extension Tap (MPN 1298200) is a 1/4"-28 UNF spiral-flute extension tap, type H3 / 2B-3B with a plug chamfer, made of high-speed steel and featuring 3 flutes. 3G Electric sources this precision threading tool as part of our industrial supply across 14 departments, with specialist expertise in combustion, pumps, and controls ensuring accurate sourcing and support.
Frequently Asked Questions
What is the OSG Extension Tap 1/4"-28 UNF used for?
This OSG extension tap is designed for threading blind holes in hard-to-reach areas. Its spiral-flute design evacuates chips upward, making it ideal for automotive, aerospace, and general manufacturing applications where extended reach and precise UNF threads are required.
What are the specifications of the OSG Extension Tap 1298200?
The OSG Extension Tap (MPN 1298200) has a 1/4"-28 UNF thread size, H3 / 2B-3B tolerance, 3 flutes, and a plug chamfer. It is made from high-speed steel and is classified as a spiral-flute extension tap for threading blind holes.
Where to buy the OSG Extension Tap 1/4"-28 UNF worldwide?
You can source the OSG Extension Tap 1/4"-28 UNF 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 UNF threads?
Select an OSG extension tap by matching the thread size (e.g., 1/4"-28 UNF), chamfer type (plug for blind holes), flute count (3 for chip evacuation), and tolerance class (H3 for 2B-3B fit). Ensure the tap length reaches your hole depth. OSG high-speed steel taps suit general-purpose threading.
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Common applications for OSGOSG 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.













