OSG Extension Tap: 1/4"-28 UNF, H3 / 2B-3B, 2 Flute, Plug Chamfer
The OSG Extension Tap (1/4"-28 UNF, MPN 1293901) 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.
SKU 3G-OTH-313635
Local availability & support
- Delivery
- Worldwide DHL shipping from Singapore; 7–14 business days door-to-door for most destinations.
- Payment
- Invoicing in USD. Bank transfer (SWIFT) and corporate PO accepted.
Need installation or engineering help?
Ask a question
Product Description
The OSG Extension Tap (1/4"-28 UNF, MPN 1293901) 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.
Frequently Asked Questions
What is an OSG extension tap used for?
An OSG extension tap is used to cut internal threads in hard-to-reach or deep-hole applications. The extended shank allows threading in recessed areas, blind holes, or where standard taps cannot reach. It is commonly used in machining, automotive, and general manufacturing for precision thread forming in steel and other materials.
What are the specifications of the OSG 1/4"-28 UNF extension tap?
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 manufacturer part number is 1293901. It is a spiral-point extension tap designed for through-hole threading in deep or obstructed locations.
Where to buy OSG extension taps worldwide?
3G Electric supplies OSG extension taps worldwide, handling full logistics and customs clearance for international orders. As a global industrial sourcing partner, we provide genuine OSG cutting tools like the 1/4"-28 UNF spiral-point extension tap (MPN 1293901) to customers across machining, automotive, and general manufacturing industries.
How to select the correct OSG extension tap for a job?
To select the correct OSG extension tap, match the thread size (e.g., 1/4"-28 UNF), tolerance class (H3 / 2B-3B), and chamfer type (plug) to your application. Consider the material being threaded and the depth required. For deep or recessed holes, choose an extension tap with sufficient shank length. Consult OSG's technical data for optimal performance.
Used in
Common applications for OSGOSG 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.
