Black Heavy Duty Single Head Open End Wrenches Repair Spanner Workshop 14mm-50mm

Match the wrench jaw size to the across-flats (AF) measurement of your fastener. For automotive work, common sizes are 14mm–22mm for engine bolts and 24mm–32mm for suspension and drivetrain components. Larger sizes (36mm–50mm) are typically used for industrial pipe fittings and heavy machinery.

Yes. The drop-forged carbon steel construction provides the tensile strength needed for high-torque fastening tasks. As with any open end wrench, apply force in the pulling direction and ensure full jaw engagement on the fastener flats to avoid slippage.

Black oxide provides moderate corrosion resistance by slowing oxidation on the steel surface. For long-term storage or use in wet environments, wipe the wrench with a light machine oil after use to extend the finish life.

These wrenches are sized in metric (mm). While some metric sizes are close to SAE equivalents (e.g., 19mm ≈ 3/4 in), using a metric wrench on an imperial fastener — or vice versa — risks rounding the fastener corners. We recommend using the correct standard for your fastener type.

Each order is for one (1) individual wrench in the size you select. This lets you replace a single worn or missing size without purchasing a full set. Select your required size from the variant options above.

A single head wrench has one open jaw at one end, while a double head wrench has two open jaws (typically at different sizes) at each end. Single head wrenches are longer relative to their jaw size, which can provide better leverage and easier handling in some applications.

After use, clean off grease and debris with a rag. Apply a thin coat of machine oil or WD-40 to prevent surface rust, especially if stored in a humid environment. Inspect the jaw opening periodically — if the jaws show visible wear or spreading, replace the wrench to avoid fastener damage.