DescriptionDIY Supplies : WoodworkingBrand Name : Origin : Mainland ChinaCertification : NONE DIN 875 00 Grade 75mm,125mm,175mm,200mm,225mm,300mm steel blade ruler Square Ruler Straight Edge Ruler Knife Edge RulerMaterial: Tool SteelLength: 75/100/125/150/175/200/250/300/400mmAccuracy: DIN 874/00 For checking the edge, using the light-gap method. The blade is bevelled on both sides, with insulated handle. Come with a protective case. Usage: Test the flatness of plate, leveling ruler, machine tool working platform, guides and accuracyworkpiece.1) Hold the knife edge perpendicular to the surface of the workpiece and check it in the longitudinal, lateral and diagonal directions2) During the inspection, if the knife edge and the plane of the workpiece are weak and uniform, the flatness of the workpiece is acceptable; if the intensity of the incoming light is different, the plane of the workpiece is uneven. It can be inserted with the feeler at the edge of the knife and the workpiece. The error of the flatness can be determined according to the thickness of the feeler.Attention:remark: different model for chooseRemark:goods color ship by randomaccording to industrial standardDue to different Monitor, the color may have differenceDue to hand measure,Please allow1-3% differencetoleranceDue to long shipping, the item may damage in transit, if the item damage, pls contact us firstly immediately before leave feedback, thanks for your understanding