BS EN 10243-1:1999:2006 Edition
$167.15
Steel die forgings. Tolerances on dimensions – Drop and vertical press forgings
| Published By | Publication Date | Number of Pages |
| BSI | 2006 | 38 |
1.1 This European Standard specifies the dimensional tolerances for steel drop and vertical press forgings made under hammers and presses.
The first part of this European Standard applies to hot forgings in the delivery condition, made in carbon and alloy steels. The tolerances specified apply to forgings not exceeding 250 kg in mass or 2 500 mm maximum dimension. Tolerances for heavier or larger forgings shall be agreed at the time of enquiry and order.
This European Standard does not apply to upset forgings made on horizontal forging machines (see EN 10243-2).
1.2 The tolerances shown in this European Standard cover both forgings to normal requirements and forgings to a closer range of tolerances. These two grades of tolerances are identified as follows:
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forging grade F with tolerances providing an adequate standard of accuracy for the majority of applications and capable of being complied with by commonly used forging equipment and production methods;
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forging grade E providing closer tolerances to assist in acommodating those instances in which the normal manufacturing standards are inadequate.
While grade E (close) tolerances may be applied to all dimensions on one forging, it is more economical to apply them only to those specific dimensions on which closer tolerances are essential. This grade should not be specified unless the additional forging cost entailed can be justified by a consequent saving in overall cost.
The tables showing dimensional tolerances are based on the R20 series of preferred numbers (see ISO 3).
Annex A gives for information some examples of the application of these tolerances for different types of closed die forgings.
1.3 Any occasional instances may necessitate the use of tolerances wider than those indicated, e.g. specially complicated designs and steels having particularly difficult forging characteristics. In such cases these standard tolerances can form only a basis on which to agree modifications appropriate to the particular circumstances.
1.4 This European Standard does not include ranges of special tolerances closer than grade E. Such requirements usually necessitate supplementary operations, e.g. hot or cold coining or special processes such as warm or cold forging.
Considerations of this nature, whilst frequently encountered, are highly individual, and vary widely. They are best dealt with by consultation at the design stage and shall be agreed between the purchaser and the supplier. This approach will ensure that optimum use is made of the forging process in fulfilling the purchaser’s special requirements at the lowest additional cost.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 1 | BRITISH STANDARD |
| 2 | National foreword |
| 7 | 1 Scope 1.1 This European Standard specifies the dimensional tolerances for steel drop and vertical press forgings made under hammers and presses. 1.2 The tolerances shown in this European Standard cover both forgings to normal requirements and forgings to a closer range of tolerances. These two grades of tolerances are identified as follows: 1.3 Any occasional instances may necessitate the use of tolerances wider than those indicated, e.g. specially complicated design… 1.4 This European Standard does not include ranges of special tolerances closer than grade E. Such requirements usually necessitate supplementary operations, e.g. hot or cold coining or special processes such as warm or cold forging. 2 Normative references 3 Symbols |
| 8 | 4 Information required in determining tolerances 4.1 Mass of forging 4.2 Shape of die line Die lines |
| 9 | 4.3 Category of steel used 4.4 Shape complexity factor Enveloping shapes of circular forgings |
| 10 | Enveloping shapes of non-circular forgings Exception in determining shape complexity factor |
| 11 | 4.5 Types of dimension Relationship between types of dimensions and die line 5 Categories of tolerances 5.1 Scope of categories |
| 12 | 5.2 Definition of categories Type of dimensions |
| 13 | Length and width dimensions between external surfaces Length and width dimensions between internal surfaces |
| 14 | Length and width dimensions from a centre to a surface |
| 15 | Mismatch Residual flash Trimmed flat |
| 16 | Application of thickness tolerances to deep hubs |
| 17 | Application of straightness tolerances Dimensions to which centre-to-centre tolerances are applicable |
| 18 | Dimensions to which centre-to-centre tolerances are not applicable (other than by negotiation) Fillet and edge radii |
| 19 | Eccentricity tolerance for deep holes |
| 20 | Tolerances for unforged stock and sheared ends 5.3 Deviations of form |
| 21 | 6 Use of tables 6.1 Table 1 and Table 2 |
| 22 | Use of tables 6.2 Table 3 and Table 4 – Tolerances for thickness and ejector marks 6.3 Table 5 – Tolerances for straightness, flatness and tolerances for centre-to-centre dimensions |
| 23 | 6.4 Table 6 – Tolerances for fillet and edge radii; tolerances for burrs; tolerances for sheared ends 7 Design procedure 7.1 Information required by the forger 7.2 Preparation of forging drawing 7.3 Indication of dimensions on forging drawing 7.4 Indication of tolerances on forgoing drawings 7.5 Importance of forging drawing |
| 24 | Drop and press forgings – Forging grade F – Tolerances for length, width, height, mismatch, residual flash and trimmed flash |
| 25 | Drop and press forgings – Forging grade E – Tolerances for length, width and height |
| 26 | Drop and press forgings – Forging grade F – Tolerances for thickness and ejector marks |
| 27 | Drop and press forgings – Forging grade E – Tolerances for thickness and ejector marks |
| 28 | Drop and press forgings – Tolerances for straightness, flatness and centre-to-centre dimensions Drop and press forgings – Tolerances for fillet, edge radii, burrs and sheared ends |
| 29 | (informative) Examples of application (informative) Examples of application Content General remarks concerning the examples Example 1: Gear General Information necessary for determining the tolerances Determining the tolerances from the tables according to EN 10243-1 |
| 31 | Example 2: Crankshaft General Information necessary for determining the tolerances Determining the tolerances from the tables according to EN 10243-1 Entry of tolerances on the forging drawing |
| 33 | Example 3: Stub axle General Information necessary for determining the tolerances Determining the tolerances from the tables according to EN 10243-1 Entry of tolerances on the forging drawing |
| 35 | Example 4: Rocker arm General Information necessary for determining the tolerances Determining the tolerances from the tables according to EN 10243-1 Entry of tolerances on the forging drawing |
