Osg 1974300 Straight Flute Tap M12x1.25 Metric Fine Hss

Product Description

The OSG 1974300 is a straight flute plug tap designed for cutting right-hand M12x1.25 metric fine internal threads in a range of ferrous and non-ferrous materials. Built from high-speed steel (HSS) with a bright, uncoated finish, this tap is suited for production and maintenance threading work. It carries a D5 thread limit and features 4 flutes, providing stable chip management in through-hole and short blind-hole applications. Overall length is 3.375 inches, with a thread length of 1.6563 inches (26.3 mm) and a shank diameter of 0.3670 inches. The plug chamfer distributes cutting load across several leading threads for smooth entry into pre-drilled holes.

This tap is intended for threading aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The M12x1.25 metric fine pitch is common in automotive, precision mechanical, and industrial assembly applications where a finer thread engagement and higher clamping force are required versus the coarse M12x1.75 pitch. It is installed by machinists and maintenance technicians using a standard tap wrench, tapping head, or CNC rigid tapping cycle. Series 141 is OSG's standard metric fine straight flute line, sized for general shop and production use.

Key Features

• M12x1.25 metric fine right-hand thread form with D5 thread limit for consistent tolerance control
• 4-flute straight design provides rigidity and stability in short-chipping materials
• Plug chamfer (3-5 thread lead) allows gradual thread engagement from the start of the cut
• High-speed steel construction withstands heat buildup in steel and cast iron applications
• Bright, uncoated finish suitable for use with cutting oil or tapping fluid across a wide material range
• No coolant-through requirement - compatible with external flood or manual lubrication

Compatibility

Designed for M12x1.25 metric fine thread applications in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel as specified by OSG for Series 141.

Installation Notes

This tap is installed by a machinist or maintenance technician using a tap wrench, tapping attachment, or rigid CNC tapping cycle. Always drill the correct tap drill diameter for M12x1.25 before threading, and apply an appropriate cutting fluid or tapping compound for the workpiece material. Secure the workpiece firmly before tapping to prevent tap breakage. Never reverse a tap under power without confirming the machine is set for rigid tapping with the correct spindle direction.