Screw Extractor Set 4 PCS for Damaged Screw Remove and Stripped by KuenuilrHIGH QUALITY: This screw extractor kit made from standard high speed steel and super hard titanium coated. The hardness is 63 65 HRC. Higher hardness than other brands extractors. SIZE: The stripped screw extractor set use for iron and steel screws with a diameter between 3 and 12mm. Easy extractors damaged screw and remove the most stubborn stripped, damaged, embedded, rusted and painted over screws and bolts. USE: This speed out screw extractor work