DIN2391-1

DEUTSCHE NORMSeptember 1994Seamless precision steel tubesDINDimensions2391Part 11C523.040.10Supersedes July 1981edition.Descriptors.Tube,steel tube,precision tube,dimensions.Nahtlose Prazisionsstahlrohre mit besonderer MaBgenauigkelt;MaBein keeping with current practice in standards published by the international Organization for Standardization (150),acomma has been used throughout as the decimal marker.国ON正Dimensions in mm1Scope and field of applicationThe limit deviations for diameters given in table 2 allow forThis standard speclfies dimensions for cold finished,ovality and apply for the cold finished (hard)(BK)and coldseamless precision steel tubes and is to be used in con-finished (soft)(BKW)conditlons.junction with DIN 2391 Part 2 which states the relevantFor heat treated tubes,i.e.cold finished and stress-reliefannealed (BKS),annealed (GBK)or normalized (NBK)星technical delivery conditions.The proforred sizes listed intable 2 are mainly used in mechanical and automotive en-tubes,the limit devlations for the dlameter increase as afunction of the wall thickness/diameter ratio (see table 1).gineering.The dimensions given in table 1 also apply to the insideWhere steel tubes of dimensions specified In this standarddiameter of steel tubes.are to comply with the technical delivery conditions listedin subclause 1.2 of DIN 2391 Part 2,they shall be orderedIn the case of intermedlate sizes,the deviations for the nextin quality grade C.largest size shall apply.The limit deviations for wall thickness shall be +10%of the2nominal size and Include the concentricity tolerance,whichDimensionsis calculated as a percentage using the following formula:The tube diameter is subject to the limlt deviations speci-fied in table 2.Tm -Tain.100If one of the limit devlations is to be zero,this shall be statedTomax +Tminin the order,e.g.instead of (55+0,25)mm,eitherwhere(5585)mmor(55-6s)mmls the largest wall thickness measured of a5tube cross section;Table 1:LImlt deviations for the diameterof heat treated tubesTi the smallest wall thickness measured of a器tube cross section.Wall thickness,Limit devlations forTubes are generally ordered in terms of outside diameterTdiameter,Dand inside dlameter.Where the wall thickness is of significance,the tubes may0,05-D and aboveAs specified in table 2.also be ordered in terms of outside dlameter and wall thick-ness or inside diameter and wall thickness.In this case,theAbove 0,05.D1,5 times the valuesup to 0,025.Dtimit devlations specified here refer only to two of threein table 2.possible parameters,the deviations for the third being sub-Above0,025·LDTwice the values in table 2.ject to agreement.Such tubes shall be ordered in qualitygrade C.SANON PIPE正能国标Continued on pages 2 to 6.18.2.03Beuth Verfag GmbH.Berilln,has the exclusive right of sale for German Standardts [DIN-NormenDIN 2391 Part 1 Engl.Price group 604.95