Precision internal threading with confidence. The Wiseman Threading Tools Taper Lead Metric HSS Tap Left Hand - M20x1 is built for clean, reliable threads in metalworking projects that require a left-hand thread.

Crafted from high-speed steel and ground to tight tolerances, this tap delivers dependable performance across a range of materials. It’s uncoated for versatile use in general-purpose tapping and adheres to ISO 529 dimensions for compatibility with standard tooling and chucks.

• Left-hand thread: Cuts internal threads in the opposite direction, ideal for components with reverse-threaded fasteners or reverse-rotating assemblies.
• Taper lead: The traditional taper at the cutting end provides easier starting thread engagement and smoother chip formation, reducing the risk of cross-threading and chatter.
• Metric M20x1: Precise 20 mm major diameter with a 1.0 mm pitch, following ISO 529 specifications for predictable results in production or repair work.
• General purpose and durable: HSS ground finish offers a balance of hardness and resilience for threading through mild steel, cast iron, aluminum, and other common metals.

Whether you’re building, repairing, or refurbishing mechanical assemblies, this left-hand tap fits standard tap handles and machines, and pairs well with cutting oil to extend life and improve finish. Use it for through-hole applications or any project requiring a left-handed internal thread.

Pro tips for best results: lubricate generously, back off periodically to break chips, and start with a light touch to seat the tool before full cutting. Store in a dry place to prevent corrosion and maximize tool longevity.