The Metric Check Nut Wrench is made from drop forged steel bar. It is available in fractional sizes ranging from 1/2” to 1-11/16” and Metric sizes from 10mm to 41mm. This industrial black wrench is commonly used for check nuts, stop nuts, jam nuts, and hydraulic fittings. Its smaller sizes are perfect for service wrenches. (Also known as Thin Head Wrenches) These are specialized tools with a 15 degree angled slotted opening, typically used for adjusting and locking thin nuts. Type: Checknut Measurement Type: Metric Size: 11MM in. Material: Steel Coating: Industrial Black Country of Origin: Made In U.S.A.