Section 6 Materials
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Naval Ships, January 2023 - Volume 2 Machinery and Engineering Systems - Part 4 Propulsion Devices - Chapter 1 Propellers - Section 6 Materials

Section 6 Materials

Parent topic: Chapter 1 Propellers

6.1 Castings for propellers

6.1.1 Castings for propellers and propeller blades are to comply with the requirements of Rules for the Manufacture, Testing and Certification of Materials, July 2022, Rules for the Manufacture, Testing and Certification of Materials (hereinafter referred to as the Rules for Materials). The chemical composition and mechanical properties of steel castings are given in Ch 4, 5 Castings for propellers and those of the copper alloys are given in Ch 9, 1 Castings for propellers

6.1.2 The specified minimum tensile strength of the castings is to be not less than stated in Table 1.6.1 Materials for propellers. The values of U in Table 1.6.1 Materials for propellers relate to castings of less than 25 tonnes in weight.

Table 1.6.1 Materials for propellers

Material Specified minimum tensile strength N/mm2 G U
Density g/cm3 Allowable stress N/mm2
Carbon steels 400 7,9 20,6
Low alloy steels 440 7,9 20,6
13% chromium stainless steels 540 7,7 41
Chromium – nickel austenitic stainless steel 450 7,9 41
Duplex stainless steels 590 7,8 41
Grade Cu 1
Manganese bronze (high tensile brass) 		440 8,3 35
Grade Cu 2
Ni-Manganese bronze (high tensile brass) 		440 8,3 35
Grade Cu 3
Ni-Aluminium bronze 		590 7,6 53
Grade Cu 4
Mn-Aluminium bronze 		630 7,5 45

6.1.3 Spheroidal cast iron load transmitting components of controllable pitch mechanisms, are to be manufactured, tested and certified in accordance with Ch 7 Iron Castings of the Rules for Materials, and have an elongation of not less than 12 per cent.

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