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

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

The OSG Extension Tap, #4-40 UNC, is a spiral-point extension tap designed for threading applications. This H2 / 2B-3B rated tool features a plug chamfer, 2 flutes, and is constructed from high-speed steel (MPN 1294000).

SKU 3G-OTH-313643

Brand
OSG
Item
Extension Tap: #4-40 UNC, H2 / 2B-3B, 2 Flute, Plug Chamfer
Category
Spiral-Point Extension Taps
Available to Order
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Local availability & support — Singapore

Local office
20 Woodlands Link #09-05, Singapore 738733
Phone
+65 8878 8355
Delivery
Same-day or next-business-day delivery within Singapore for in-stock items; 7–14 days for factory-order parts from Europe.
Payment
Invoicing in SGD. PayNow, bank transfer, and corporate PO accepted.
Ships to
Singapore

Technical Specifications

OSG
Manufacturer Part Number
1294000
Type
H2 / 2B-3B, Plug Chamfer, High Speed Steel
Flute
2

Technical Documents

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

Product Description

The OSG Extension Tap, #4-40 UNC, is a spiral-point extension tap designed for threading applications. This H2 / 2B-3B rated tool features a plug chamfer, 2 flutes, and is constructed from high-speed steel (MPN 1294000).

Frequently Asked Questions

What is OSG Extension Tap #4-40 UNC used for?

The OSG Extension Tap #4-40 UNC is used for threading blind or deep holes in metal parts where a standard tap cannot reach. Its extended length and spiral-point design push chips forward, making it ideal for production machining, automotive, and general manufacturing applications.

What are the specifications of OSG Extension Tap #4-40 UNC?

This OSG extension tap has a #4-40 UNC thread size, H2 / 2B-3B tolerance, 2 flutes, plug chamfer, and is made of high-speed steel. The manufacturer part number is 1294000. It is designed for threading through holes in steel, aluminum, and other common workpiece materials.

Where to buy OSG Extension Tap #4-40 UNC worldwide?

3G Electric supplies the OSG Extension Tap #4-40 UNC (MPN 1294000) to customers worldwide. We handle full logistics, customs clearance, and delivery to your facility. Contact us for a quote and lead time on this precision threading tool.

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

To select the correct OSG extension tap, match the thread size (e.g., #4-40 UNC), chamfer type (plug for through holes), and flute count to your material and hole depth. The H2 / 2B-3B tolerance ensures a standard fit. For deep or blind holes, confirm the extension length meets your reach requirement.

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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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)

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