FOUNDRY TECHNOLOGY - Zollern

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VDG SPECIFICATION P 695 INVESTMENT CASTINGS: TERMS OF DELIVERY Part 1: General conditions 1. Applications VDG Specification P 695 lays down the general technical terms of delivery for investment castings made by the lost wax method from standard and non-standard casting materials or metals. Additional, specific requirements relating to certain materials are laid down in separate standards. The purchaser specifies his requirements for the casting in accordance with its intended purpose. Appendix A of the specification contains a check list providing negotiators with rapid information about various points which can be agreed when an order is placed. These refer to corresponding subsections and extracts from the VDG specification. We expressly recommend that only materials be chosen which qualify as casting materials in official standards. Part 2: Quality grades 1. General The present specification lays down various grades of external and internal quality for the condition of materials on delivery. The grades are subdivided in accordance with the requirements which the results of non-destructive tests must meet. 2. Quality grades 2.1 Allocation of quality grades The allocation of external quality grades is determined in accordance with tests based on the magnetic leakage-flux method or dye method. The allocation of internal quality grades is determined by a radiographic test and/or X-ray examination. Extract from the guideline drawn up by the Investment Castings Committee of the VDG (Association of German Foundrymen). INVESTMENT CASTING
VDG SPECIFICATION P 690 8 9 DIMENSIONAL TOLERANCES, SURFACES, MACHINING ALLOWANCES P690, 4th edition, February 1992 Directive compiled by the Special Committee on ‘Investment Casting’ GERMAN ASSOCIATION OF <strong>FOUNDRY</strong> SPECIALISTS Available from VDG-Center of Information Sohnstr. 70, 40237 Düsseldorf Tel. +49 (0) 211/68 71-254 Fax. +49 (0) 211/68 71-364 Email info@vdg.de www.vdg.de Slightly abridged version with the permission of the German Association of Foundry Specialists. 1. Definition and scope 1.1 Investment casting is a process by which a high surface quality can be manufactured through the formation of dimensionally accurate casting. The patterns produced by injection moulding are heat disposable and are melted out after manufacture of the ceramic moulds. The ceramic moulds are destroyed after casting. For this reason, both the pattern and the moulds are designated ‘lost’ using this method. Casting usually takes place into hot moulds. 1.2 Metals and iron, aluminium, nickel, cobalt, titanium, copper and magnesium-based alloys can be used for investment casting. Depending on the type of alloy, casting is performed exposed to the air, under inert gas in a vacuum. 1.3 This technical memorandum does not apply precious metals cast using the dewaxing method, to products of the jewellery industry, dental laboratories or to art casting. 2. Purpose 2.1 This technical memorandum defines dimensional tolerances, specifies machining allowances and surface roughness corresponding to the start of the art in the field of investment casting. It serves as a basis for optimum economic cooperation between investment casting suppliers and buyers. 2.2 The specifications mentioned here refer to sandblasted preserved or pickled surfaces in their delivered condition. Exception must be agreed where work processes are involved which alter the dimensional tolerances. 2.3 Unless otherwise agreed, initial samples are supplied for first-time orders. These are used to permit concrete mutual agreement between supplier and purchaser. Initial samples must be appraised by the buyer, followed by a written release to the foundry for series production. Deviation acknowledged by the release or with positive appraisal of the initial samples are binding for the production process and must be entered into the (casting) drawing.
Page 1 and 2: FOUNDRY TECHNOLOGY INVESTMENT CASTI
Page 3 and 4: ZOLLERN CASTINGS TECHNOLOGY - PERFO
Page 5 and 6: 1 Patternmaking 2 Assembly of the c
Page 7: 6 7 Table 2: Machining allowances d
Page 11 and 12: 4. Dimensional tolerances 4.1 Linea
Page 13 and 14: 5. Surface properties For cast surf
Page 15 and 16: Ceramic cores Ceramic cores are use
Page 17 and 18: Inside edges, notches Sharp inside
Page 19 and 20: Holes and slots Mould and draught a
Page 21 and 22: Investment casting are frequently r
Page 23 and 24: Economy It makes economic sense to
Page 25 and 26: 10 10 Aluminum electronic housing f
Page 27 and 28: CONTACT 26 27 ZOLLERN GmbH & Co. KG

FOUNDRY TECHNOLOGY - Zollern

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