Wiseman Threading Tools Second Lead Metric HSS Tap Left Hand - M12x1.5 is a precision ground, uncoated tapping instrument engineered for fast, reliable left-hand threading in metalworking projects. Built from high-speed steel and finished for general-purpose use, this tap delivers clean, accurate threads across a range of materials.

Why this tap stands out

Designed around ISO 529 standards, this M12x1.5 left-hand tap uses a second lead (double-start) configuration to reduce the turning effort required to advance the thread. The result is faster thread formation without sacrificing accuracy, making it ideal for production runs or field repairs where time matters as much as precision.

• Left-hand threading capability: Perfect for components that reverse-rotate or require a reverse-thread fastener, ensuring reliable assembly and disassembly when needed.
• Second lead (double-start) design: Cuts more aggressively than a single-start tap, accelerating the tapping process and shortening cycle times on compatible materials.
• Metric M12x1.5 specification: A common size and pitch in mechanical and automotive applications, compatible with ISO 529 threading standards.
• Uncoated HSS construction: Uncoated high-speed steel provides strong performance across a broad range of machinable metals, with compatibility for standard cutting fluids to reduce tool wear.
• General-purpose, ready-to-use tooling: A practical, reliable choice for shops that need a capable, versatile tap for everyday threading tasks.

Ideal use cases and who benefits most

This tap is well-suited for reverse-thread assemblies in automotive components, machinery housings, and fabrication projects where left-handed fasteners or reverse applications are common. It’s equally at home in repair work on equipment that uses left-hand threads or during assembly/disassembly tasks that require a reverse-rotation approach. Whether you’re building a small-run prototype or performing routine maintenance, this tap helps you get precise threads quickly and consistently.

Practical tips for best results

• Use the appropriate cutting fluid or lubrication to minimize heat and extend tool life during tapping.
• Secure the workpiece firmly to prevent chatter and maintain accurate alignment with the tap’s flutes.
• Start with steady, medium-pressure advances and maintain a consistent feed to avoid thread deformation.
• Periodically back the tap out to break and clear chips, then continue tapping to complete the thread.
• Pair with compatible drill/driving tools designed for left-hand threading to ensure a clean, true thread profile.

Technical specifications at a glance

• Tool type: Threading tap
• Material: High-speed steel (HSS), ground finished
• Coating: Uncoated
• Thread direction: Left-hand
• Lead: Second lead (double-start)
• Size and pitch: M12 x 1.5
• Standards: ISO 529
• Lead configuration: USA plug lead