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OSG Extension Tap: #4-40 UNC, H2 / 2B-3B, 2 Flute, Bottoming Chamfer - Spiral-Flute Extension Taps
OSGSpiral-Flute Extension Taps

OSG Extension Tap: #4-40 UNC, H2 / 2B-3B, 2 Flute, Bottoming Chamfer

The OSG Extension Tap (#4-40 UNC, MPN 1296100) is a spiral-flute extension tap with a bottoming chamfer, made from high-speed steel. It features a 2-flute design and is rated H2 / 2B-3B for thread class compatibility.

SKU 3G-OTH-310981

Brand
OSG
Item
Extension Tap: #4-40 UNC, H2 / 2B-3B, 2 Flute, Bottoming Chamfer
Category
Spiral-Flute Extension Taps
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Technical Specifications

OSG
Manufacturer Part Number
1296100
Type
H2 / 2B-3B, Bottoming Chamfer, High Speed Steel
Flute
2

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

Product Description

The OSG Extension Tap (#4-40 UNC, MPN 1296100) is a spiral-flute extension tap with a bottoming chamfer, made from high-speed steel. It features a 2-flute design and is rated H2 / 2B-3B for thread class compatibility.

Frequently Asked Questions

What is the OSG #4-40 UNC extension tap used for?

The OSG #4-40 UNC extension tap is used for threading blind holes in hard-to-reach areas. Its 2-flute, bottoming chamfer design allows threading close to the bottom of a hole, while the extended length provides access in deep or obstructed applications. It is suitable for use in steel and other materials requiring precise internal threads.

What are the specifications of the OSG extension tap MPN 1296100?

The OSG extension tap MPN 1296100 is a #4-40 UNC tap with a H2 / 2B-3B thread class. It has 2 flutes, a bottoming chamfer, and is made from high-speed steel. The spiral-flute design aids chip evacuation. This tap is designed for threading blind holes and is part of OSG's spiral-flute extension tap product type.

Where to buy OSG extension taps worldwide?

You can source OSG extension taps, including the #4-40 UNC model MPN 1296100, through 3G Electric. As a global industrial equipment distributor since 1990, 3G Electric handles full logistics, customs clearance, and delivery to worldwide destinations. Contact 3G Electric for availability and lead time on this OSG tap.

How to select the correct OSG extension tap for a threading application?

To select the correct OSG extension tap, match the thread size (e.g., #4-40 UNC) and thread class (e.g., H2 / 2B-3B) to your hole requirements. Choose a bottoming chamfer for blind holes and a spiral-flute design for chip evacuation. Ensure the tap length provides sufficient reach. OSG taps are precision-ground from high-speed steel for durability.

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-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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OSG Extension Tap: #10-32 UNF, H3 / 2B-3B, 3 Flute, Bottoming Chamfer, High Speed Steel (MPN 1297500)
OSG Extension Tap: 1/4"-20 UNC, H3 / 2B-3B, 3 Flute, Bottoming Chamfer, High Speed Steel (MPN 1297900)
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OSG Extension Tap: 1/4"-20 UNC, H3 / 2B-3B, 3 Flute, Bottoming Chamfer, High Speed Steel (MPN 1297900)
OSG Extension Tap: 1/4"-20 UNC, H3 / 2B-3B, 3 Flute, Bottoming Chamfer, High Speed Steel (MPN 1298100)
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OSG Extension Tap: 1/4"-20 UNC, H3 / 2B-3B, 3 Flute, Bottoming Chamfer, High Speed Steel (MPN 1298100)
OSG Extension Tap: 5/8"-11 UNC, H3 / 2B-3B, 4 Flute, Plug Chamfer, High Speed Steel (MPN 1299200)
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OSG Extension Tap: 5/8"-11 UNC, H3 / 2B-3B, 4 Flute, Plug Chamfer, High Speed Steel (MPN 1299200)

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OSG Extension Tap: #6-32 UNC, H3 / 2B-3B, 2 Flute, Plug Chamfer, High Speed Steel (MPN 1296200)
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OSG Extension Tap: #10-24 UNC, H3 / 2B-3B, 3 Flute, Bottoming Chamfer, High Speed Steel (MPN 1297100)
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OSG Extension Tap: 3/8"-16 UNC, H3 / 2B-3B, 3 Flute, Bottoming Chamfer, High Speed Steel (MPN 1298700)
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OSG Extension Tap: 3/8"-16 UNC, H3 / 2B-3B, 3 Flute, Bottoming Chamfer, High Speed Steel (MPN 1298700)
OSG Extension Tap: 7/16"-14 UNC, H3 / 2B-3B, 3 Flute, Plug Chamfer, High Speed Steel (MPN 1298800)
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OSG Extension Tap: 7/16"-14 UNC, H3 / 2B-3B, 3 Flute, Plug Chamfer, High Speed Steel (MPN 1298800)