Mat.No. 1.1186, DIN Ck40, AISI 1040

Designation by Standards

Chemical Composition (in weight %)

Description CK40 steel has a higher (0.40%) carbon content for greater strength than the lower carbon alloys. It is hardenable by heat treatment, quench and tempering to develop 150 to 250 ksi tensile strength.  Applications Used for crankshafts, couplings and cold headed parts.  Physical properties (avarage values) at ambient temperature Modulus of elasticity [10³ x N/mm²]: 210  Density [g/cm³]: 7.84 Soft Annealing Heat to 870-980^oC, cool slowly in furnace.  Normalizing Normalizing temperature: 890^oC. Stress Relieving Stress relieving to remove machining stresses should be carried out by heating to approx. 590^oC, holding for 1-2 hours at heat, followed by air cooling. This operation is performed to reduce distortion during heat treatment. Hardening Harden from a temperature of 840-898^oC followed by water quenching. Tempering Tempering from the quenched condition may be done at 320 to 700^oC depending upon the strength desired. Forging Hot forming temperature: 1100-850^oC.  Machinability Machinability is good, rated at 60% that of the AISI 1112 alloy used as a 100% machining rated steel.  Corrosion Resistance  This is a steel alloy and will rust if not protected. it is not corrosion resistant. Welding  CK40 steel is weldable by all of the welding methods. However with its higher carbon content it is important to use both pre-heat at 150 to 260^oC and post-heat at 590 to 650^oC practice per an approved welding procedure. Cold working  In the annealed state the CK40 alloy is readily cold worked by conventional methods. Forms manufactured: Please see the Dimensional Sales Program.  Disclaimer The information and data presented herein are typical or average values and are not a guarantee of maximum or minimum values. Applications specifically suggested for material described herein are made solely for the purpose of illustration to enable the reader to make his own evaluation and are not intended as warranties, either express or implied, of fitness for these or other puposes. There is no representation that the recipient of this literature will receive updated editions as the become available. Unless otherwise specified, registered trademarks are property of Metal Ravne company. Copyright 2015 by Metal Ravne. All rights reserved. Contact our Sales Office for more information.