OSG Extension Tap: 1/4"-20 UNC, H3 / 2B-3B, 2 Flute, Plug Chamfer
The OSG Extension Tap (1/4"-20 UNC, MPN 1295001) is a spiral-point extension tap with a plug chamfer, made from black oxide high-speed steel. It features 2 flutes and is rated H3 / 2B-3B for thread class compatibility.
SKU 3G-OTH-313555
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Product Description
The OSG Extension Tap (1/4"-20 UNC, MPN 1295001) is a spiral-point extension tap with a plug chamfer, made from black oxide high-speed steel. It features 2 flutes and is rated H3 / 2B-3B for thread class compatibility.
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 allows access to recessed areas in automotive, aerospace, and general machining applications. The 2-flute spiral-point design pushes chips forward, reducing clogging in through-hole threading.
What are the specifications of the OSG Extension Tap MPN 1295001?
The OSG Extension Tap MPN 1295001 has a 1/4"-20 UNC thread size with H3 / 2B-3B tolerance class. It features a 2-flute design, plug chamfer, and is made from black oxide high-speed steel. This spiral-point extension tap is designed for threading steel and non-ferrous materials in hard-to-reach locations.
Where to buy the OSG Extension Tap 1/4"-20 UNC worldwide?
You can source the OSG Extension Tap 1/4"-20 UNC (MPN 1295001) worldwide through 3G Electric. As a global industrial equipment distributor since 1990, we handle full logistics, customs clearance, and delivery to any international destination. Contact us for availability and lead time.
How to select the correct OSG extension tap for deep-hole threading?
To select the correct OSG extension tap, match the thread size (e.g., 1/4"-20 UNC) and tolerance class (H3 / 2B-3B) to your workpiece. Choose a plug chamfer for blind holes or a taper chamfer for through holes. Ensure the tap length reaches the required depth without bottoming out. Consult OSG's technical data for material-specific speeds.
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3G Electric supplies OSG spiral-point extension taps. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.















