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OSG Extension Tap: 1/4"-28 UNF, H3 / 2B-3B, 2 Flute, Plug Chamfer - Spiral-Point Extension Taps
OSGSpiral-Point Extension Taps

OSG Extension Tap: 1/4"-28 UNF, H3 / 2B-3B, 2 Flute, Plug Chamfer

The OSG Extension Tap (1/4"-28 UNF, MPN 1295101) 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-313569

Brand
OSG
Item
Extension Tap: 1/4"-28 UNF, H3 / 2B-3B, 2 Flute, Plug Chamfer
Category
Spiral-Point Extension Taps
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Technical Specifications

OSG
Manufacturer Part Number
1295101
Type
H3 / 2B-3B, Plug Chamfer, Black Oxide High Speed Steel
Flute
2
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OSG Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The OSG Extension Tap (1/4"-28 UNF, MPN 1295101) 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"-28 UNF used for?

The OSG Extension Tap is used for threading blind or deep holes in metalworking, particularly where standard taps cannot reach. Its extended length allows access to recessed areas in automotive, aerospace, and general manufacturing applications. The 1/4"-28 UNF size creates fine threads in steel, aluminum, and other materials.

What are the specifications of the OSG Extension Tap MPN 1295101?

This OSG Extension Tap has a 1/4"-28 UNF thread size, H3 / 2B-3B tolerance, 2-flute design, plug chamfer, and black oxide high-speed steel construction. The H3 tolerance ensures precise thread fit for class 2B or 3B holes. It is designed for spiral-point geometry to push chips forward in through-hole applications.

Where to buy OSG Extension Tap 1/4"-28 UNF worldwide?

3G Electric supplies the OSG Extension Tap 1/4"-28 UNF (MPN 1295101) worldwide. As a global industrial distributor, we handle full logistics, customs clearance, and delivery to your facility. Contact us for availability and lead time. We source genuine OSG tooling for manufacturing and maintenance operations.

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

Select the OSG extension tap based on thread size (e.g., 1/4"-28 UNF), hole depth, and material. The H3 / 2B-3B tolerance suits precision threading. Use a plug chamfer for blind holes and a 2-flute spiral-point design for through holes. Match the tap to your workpiece hardness and machine type for optimal thread quality.

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 spiral-point 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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