Otaisteel is stable and reliable supplier for fortune 500 companies at home and abroad, such as thyssenkrupp, china north industries group corporation limited. Otai exports various tool steel and alloy to more than 30 countries from Europe and American, middle East and Asia. our steel materials meet DIN/ ASTM/EN/JIS ect different international standards. AISI 4140 Steel is a Alloy Structural Steel belong to ASTM A29/A29M Steel Grade standard. AISI 4140 used in Oil and Gas industry and Large Machinery Strutural. 4140 Steel China Supplier and factory Otai Special Steel Supply 4140 steel in Round bar, Plate, Flat bar, Square, Forging Ring and others any shape. And provide cutting, sawing, milled, machining processing. Established in 1999, first begin with Yao Teng Steel Brand, Otai Steel supplies a wide range of carbon, alloy and stainless steel products, including high speed tool steel, cold works tool steel, hot works tools steel, plastic mould steel, engineering steel and machine structural steel etc. After almost 20 years development and growing, Otai Steel becomes one comprehensive special steel factory, stockist and exporter. Combined with experienced exporting team and professional technical knowledge,Otais 42CrMo4 special steel is produced by the only one imported advanced steel making equipment. Welcome to send email to us .