Open Ended Spanner Heavy Duty Wrench Impact - Single End 14mm 16mm-90mm Black

Measure the across-flats (AF) distance of your nut or bolt head — this is the distance between two parallel flat sides. Match that measurement in millimeters to the wrench size. For example, a fastener with 24mm AF requires the 24mm wrench. If you are unsure, a digital caliper gives the most accurate reading.

This wrench is rated for impact-style manual use — meaning it is built to withstand the shock loads generated when striking the handle with a hammer or mallet (a common technique for loosening seized fasteners). It is not designed to be mounted directly onto a pneumatic or electric impact driver. For powered impact use, a dedicated impact socket set is the appropriate tool.

The matte black surface treatment provides a base level of corrosion resistance against moisture and mild chemical exposure typical in workshop environments. Like all surface treatments on steel tools, it can wear at contact points over time with heavy use. Wiping the wrench with a light machine oil after use will extend the finish life and maintain corrosion protection.

This wrench is sized in metric millimeters and is intended for metric fasteners. While some metric sizes are close in jaw width to certain SAE sizes (for example, 19mm is close to 3/4 in), using a metric wrench on an SAE fastener — or vice versa — risks rounding the fastener flats. Always match the wrench size to the fastener's stated measurement standard.

A single open-end design is preferred when access is restricted to one side of a fastener, when working on large-diameter nuts where a box-end would be impractical, or when you need maximum handle length for leverage on a specific size. For large industrial fasteners in the 50mm–90mm range, open-end spanners are often the only practical hand tool option.

The 2Pcs pack contains two wrenches of the same selected size. This is useful for two-wrench techniques (holding one fastener while turning another on the same fitting), for shared toolkits where two technicians may need the same size simultaneously, or simply as a backup in case one wrench is misplaced on a job site.

Sizes run from 14mm to 90mm. For common passenger vehicle work: 17mm, 19mm, and 21mm cover most wheel lug nuts; 22mm and 24mm are typical for front hub and axle nuts on smaller vehicles; 27mm, 30mm, and 32mm appear on larger axle and suspension components. Sizes 36mm and above are more common on commercial vehicles, agricultural equipment, and industrial machinery.