Precision Twist Drill 1010017 Plug Tap 1/4-28 2.5in Cobalt

Product Description

The PRECISION TWIST DRILL 1010017 is a 1500 Series plug tap designed for cutting internal threads in a wide range of materials. It features a general purpose straight flute geometry with a plug chamfer that provides 1.5 inches of cutting depth, making it well suited for through-hole and moderately deep blind-hole tapping applications. Ground from cobalt steel, this tap handles higher heat and harder workpiece materials than standard high-speed steel taps. The bronze-oxide finish reduces friction and improves chip flow during the threading operation. It is sized for 1/4-28 UNF threads and measures 2.5 inches in overall length.

This plug tap is used in machine shop, field fabrication, and maintenance applications where a clean, accurate 1/4-28 UNF thread is required. The plug chamfer style — with its moderate lead-in taper — is the most common choice for general threading work, suitable for starting in a drilled hole and completing a thread with minimal hand pressure. Cobalt steel construction makes it a practical choice when threading stainless steel, cast iron, or other abrasion-resistant alloys that would wear out carbon-steel taps prematurely.

Key Features

• 1500 Series plug tap with standard straight-flute geometry for general purpose threading
• Plug chamfer style with 1.5 inches of cutting depth for reliable thread starts in through and blind holes
• Cobalt steel construction for improved heat and wear resistance over standard HSS taps
• Bronze-oxide finish reduces friction and aids chip evacuation
• Sized for 1/4-28 UNF threads — 2.5 inches overall length
• Sold individually (1 per pack)

Compatibility

Designed as a general purpose replacement or new-installation tap for any application requiring a 1/4-28 UNF internal thread in ferrous and non-ferrous materials.

Installation Notes

Plug taps are installed by machinists and maintenance technicians using a tap wrench, T-handle, or machine tapping head. Always use the correct tap drill size for 1/4-28 UNF before tapping to avoid tap breakage. Apply a suitable cutting fluid appropriate to the workpiece material and back the tap out periodically to break chips and clear the flutes. Never force a tap — if resistance increases sharply, reverse and clear chips before continuing.

Technical Specifications

• Series: 1500
• Type: General Purpose Straight Flute Plug Tap
• Thread Size: 1/4-28 UNF
• Chamfer Style: Plug
• Cutting Depth: 1.5 inches
• Overall Length: 2.5 inches
• Material: Cobalt Steel
• Finish: Bronze Oxide
• Package Quantity: 1
• Weight: 0.09 pounds

Standard Information

• Brand: PRECISION TWIST DRILL
• Manufacturer Part Number: 1010017