EN 10031-2003 pdf download.Semi-finished products for forging-Tolerances on dimensions shape and mass.
This EN 10031 specifies the tolerances on dimensions, shape and mass for semi-finished products
intended to undergo hot forming by forging, i.e. blooms, slabs and billets made of:
— general purpose steels, in accordance with EN 10250-ito 4;
— steels for pressure purposes, in accordance with EN 10222-ito 5.
It does not cover semi-finished products intended for drop forging which are covered by EN 10243.1.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication applies (including amendments).
EN 10079:1992, Definition of steel products.
3 Terms and definitions
For the purposes oI this European Standard, the terms and definitions given in EN 10079:1992 apply.
4 Appearance and soundness
4.1 General
The semi-finished products shall be sound and free from defects such as segregation, cracks, laminations and
other imperfections that preclude their intended use.
4.2 Removal of surface detects
Surface defects shall be removed by dressing in order to conform with 4.1. Dressing may be carried Out by chipping and/or grinding or by any suitable method providing:
— the resulting depression for a single face shall not fall below a value equal to a maximum of 2% of the nominal size or 3 mm, whichever is the greater:
— in the case of removal of defects from various faces of the same cross section. the residual transverse dimensions shall remain within the specified tolerances:
— > 150 mm: i 4,5 mm or ± 2°!. whichever is the greater.
5.1.2 Square or circular semi-finished products
The tolerance on the specified side length a or diameter d shall be:
— ≤ 150 mm: ± 3% or ± 3 mm, whichever is the greater;
— ,. 150 mm: ± 4,5mm or ± 2% whichever is the greater.
5.2 Diagonal tolerances
The difference between the two diagonals of the same section shall be ≤ 6 % of the larger of the two diagonals for semi-finished products of nominal width ≤ 200 mm. For wider semi-finished products, the tolerance shall be the subject of agreement at the time of enquiry and order.
5.3 Length tolerances
5.3.1 Delivery in standard lengths
If standard lengths are ordered, a tolerance of ± 1000 mm shall apply. Semi-finished products shall have a length  1000 mm unless agreed at the time of enquiry and order.
In addition, for semi-finished products of nominal cross-sectional area ≤ 22 500 mm2, only 10 % (relative to the mass of the order) of semi-finished products shorter than the values indicated is permitted per delivery.
For semi-finished products of nominal cross-sectional area > 22 500 mm2, the percentage of short semi-finished products shall be the subject of agreement at the time of enquiry and order.
5.3.2 Delivery in fixed lengths
K fixed lengths are ordered, the following tolerance classes apply:
a) Normal tolerance, ± 250 mm:
b) Tightened tolerance, ± 100 mm;
C) Reduced tolerance, ± 50 mm.
The tolerance class shall be specified at the time of order. If there is no tolerance indication, the normal tolerance (± 250 mm) applies.
Special tolerances lower than those specified in a). b) or C) may be agreed at the time of enquiry and order. It agreed at the time of enquiry and order, the tolerance may be totally positive or totally negative.
In addition, if specified at the time of enquiry and order, 20 % of the semi-finished products shall be permitted in sub-multiples of the service length: the tolerances applicable to these short bars are one class tighter than those specified for the ordered length.
6 Shape tolerances
6.1 Straightness
Semi-finished products shall be delivered hot formed without any special straightening. The permissible deviations shall be:
— in the case of bending, 10 mm per metre uniformly distributed (see Figure 1);
— in the case of local deformations or waviness, 20 mm per metre (see Figure 2).
It specified at the time of enquiry and order, special straightening shall be carried out; the permissible deviations shall be less than 4 mm per m.
Tolerances on deformation of the ends may be agreed at the time of enquiry and order.
6.2 Twist
Square semi-finished products shall not have a twist angle greater than 42 per m, with a maximum of 10° for lengths ≤ 6 m and 15° for greater lengths.
Rectangular semi-finished products shall not have a twist likely to adversely affect their application. If specified at the time of enquiry and order, the tolerances specified for square semi-finished products also apply for rectangular semi-finished products.
7 Tolerances on mass
7.1 Tolerances on mass per unit length
7.1.1 case of billets
The mass shall be between 88% and 100% inclusive of the theoretical mass per unit length corresponding to the nominal cross-sectional area (square or rectangle of the corresponding dimensions).EN 10031-2003 pdf download.