1、UDC 621.882.082.1 : 62-4141-415 DEUTSCHE NORMEN October 1971 DIN 7952 E -i. =- Sheet Metal Rim Holes with Screw Thread - -5 26 e= % ss 250 Prepunch Hole Diameters 2s: s tS Part 2 - O0 OOC - a- Blechdurchzie mit Gewinde; Vodochdurchmesser O?C c mx ea .B 0- S 3; e -E Dimensions in mm .- E E; d : 5 ts
2、pr 0“- The dimensions listed in the Tables are guide values (see explanations) -a 5 1“ I - 31 oc 0- I - Standard screw threads M 2 to M 10 =U - If o 8 5 a y i nE 3 0 02.80 No prepunch hole diameters have been specified for the sheet metal rim holes marked by an x. The corresponding sheet metal rim h
3、oles according to DIN 7952 Part 1 can only be manufactured in the form of stamped or plunged rim holes. See DIN 7952 Part 1 for dimensions of sheet metal rim holes with screw thread. Continued on page 2 Explanations on page 3 - - Ve*.-Nr. 0104 Page 2 DIN 7952 Part 2 Fine screw threads M 2 x 0.25 to
4、M 10 x 1 -p 0.6 1.8 0,s 1 E 2,5 1.8 1.3 1.5 1.2 1.4 Prepunch hole diameter d4 for screw threads M2,5x0,35 M3x0,35 M4x0,5 +i- q-t- 15 M5x0,5 M6x0,75 MBx0,75 .I d lox 1 No prepunch hole diameters have been specified for the sheet metal rim holes marked by an x. The corresponding sheet metal rim holes
5、according to DIN 7952 Part 1 can only be manufactured in the form of stamped or plunged rim holes. DIN 7952 Part 2 Page 3 Explanations The accuracy of gauging sheet metal rim holes is influenced by a number of factors which produce different effects. It is therefore not possible to lay down precise
6、dimensional data, all the more as manu- facturing developments which are taking place at present should not be hindered by any technical manufacturing restrictions. Furthermore, any guidelines which are tied up with particular materials should not be pursued. In order to ensure on the other hand tha
7、t essential data are available for the manufacture of sheet metal rim holes, guidelines have been laid down for the prepunch hole diameter d4. These guidelines relate to sheet metal rim holes with a minor diameter of the screw thread d2 according to DIN 7952 Part 1, .e. with a minor diameter of the
8、screw thread within the 5H tolerance zone. The guidelines relating to the prepunch hole diameter are calculated values, and are based on an equal volume of the base metal to the material of the finished rim hole. This condition is fulfilled by the following equation: wherein: d2 Minor diameter of sc
9、rew thread (manufacturing d4 Prepunch hole diameter d5 Mean value of collar diameter dimension) h Reduced collar height (the volume reduction caused by the recessing at the minor diameter of the screw thread has been taken into account) s Sheet thickness The M 2.3 and M 2.6 screw threads in previous use are not recognized in ISO/R 261, compare DIN 13 Part 1. For these screw threads, the prepunch hole diameters listed below are recommended: d4 for screw threads M2,3 I M2,6 h - 8 8
