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  4140 chrome plated steel bar   is made of 4140 round steel bar which has achieved high hardness and corrosion resistance through heat treatment and hard chrome plating . 4140 also named 42CrMo4, It is a chromium and molybdenum alloy steel that has an excellent weight to strength ratio. It is considerably stronger than standard steel. Although it is chromium steel and often referred to as “chromoly steel” it does not contain as much chromium as stainless steel. Therefore the corrosion resistant is improved compared to standard steel but not to the same degree as stainless steels. The purpose of the molybdenum is to add uniformity of hardness and strength to this alloy. 4140 responds readily to heat treatment and is relatively easy to machine in the heat treated condition. It has a tensile strength of 150,000 psi, yield strength of 130,000 psi and approximately 35-45% elongation. This metal is typically used for bolts couplings, axle shafts,  cylinder piston rods , tractor arms, clutch

  42CrMo4+QT  means this material is in the quenched and tempered condition (+QT).  42CRMO4 (+QT) medium carbon bearing steel in the form of hot rolled/hot forged quenched and tempered seamless forged parts. This specification covers Material Grade, Homogeneity, Microstructure and Mechanical properties. Forged parts produced with this steel are used for manufacturing bearing retaining parts. All other requirements, common to medium carbon bearing steel grades in the form of rolled/hot forged,quenched and tempered ring are specified in EN 10083-3 and ISO 683-17. 42CrMo4 Equivalent Material 42CrMo4 material (1.7225 steel) equivalent to US ASTM AISI SAE, Germany DIN, British BSI, France NF, ISO, Japanese JIS and Chinese GB standard. (For reference) 42CrMo4 Equivalent Grade European Union US China Japan ISO Standard Grade (Steel Number) Standard Grade Standard Grade Standard Grade Standard Grade EN 10083-3 42CrMo4 (1.7225) AISI SAE; ASTM A29/A29M 4140 GB/T 3077 42CrMo JISG 4105 SCM440 ISO

  Chrome hollow bar   also called chrome hollow rod/shaft or chrome tubing in many countries. chrome hollow bars are made of   cold drawn seamless tubes   or hollowed bars, by grinding and precision polishing on the outside diameter and then chrome plated to a certain thickness on the OD. Chrome hollow bar and chrome solid bar both very popular components for producing   hydraulic cylinder . Heat Treatment Of Chrome Hollow Bar 1.Q+T(Quenched+Tempered) Quenching and tempering refers to the hardening (Quenching) of hollow rod materials at temperatures from 800 — 1,100 °C with a subsequent re-heating (Tempering) at temperatures from 540 — 680 °C. Hardening is a heat treatment process that comprises of austenitizing and rapid cooling. On account of the associated microstructure transformation during the cooling process, the chrome hollow steel rod is hard but also brittle. The subsequent high tempering temperature leads to an increased yield and tensile strength as well as to high elongati