Force is applied to a spanner, the force acts on the joint between the jaw and the shaft. Good-quality open-jaw spanners do not take this fact into consideration. In the context of normal hard work, this can lead to the tool breaking, causing considerable personal injury. To reduce the danger of breakage, we add more material where the greatest loads are to be found and take it away from the places that are not under such stress. In this way, we are able to manufacture extremely sturdy, slim and light tools which also facilitate working in confined spaces due to their compact designs. Drop-forged from high-grade special steels. Optimum hardening in continuous furnaces with no scale build-up or skin decarburisation. Gentle quenching in oil. Good resistance to bending and low weight thanks to STAHLWILLE's typical double-T profile. Snug-fitting, skin-friendly surfaces thanks to STAHLWILLE's rounded finish. Tougher than any bolt thanks to the forged double hex. Thinner than conventional rings – facilitating work in confined spaces. Higher than standard nuts – prevents the spanner jamming on the nut. STAHLWILLE's Quality Assurance System was awarded an internationally recognised certificate in accordance with DIN ISO 9001 by the DQS (German Association for the Certification of Quality Assurance Systems).