good workmanship, abrasion hardness,high wearability, tartness, fast cutting speed and ... steel materialb)various size for choosec)all kinds of shaped)fast cutting speedUse: suitable for glass, stainless ... one side, crossing, ovalFeatures:good workmanship, abrasion hardness,high wearability, tartness, fast cutting speed and long tool lifeCoating ... with me at any time:) diamond types of hand files