marking device sheet metal tensile specimen

measure rupture elongation after specimen brake

marking device flat specimen
scratches marks 5 mm distance into flat tensile specimen < 5 seconds

marking device sheet metal specimen

 

 

Marking device flat tensile specimen in seconds

insert, lower, press, remove <5 second

With this marking device tensile / flat specimens can be marked in the simplest way in order to be able to measure the elongation at break manually afterwards. The markings are carved. For most materials these have no influence on the test result.

The marking device is suitable for all flat specimens with a length Lt up to 300 mm and specimen thickness up to 15 mm.

Marking operation:

  • lift the moving part
  • Insert sample centric ally
  • Lower the marking beam and place the scribers on the flat specimen
  • Press on the marking bar with more or less force and push down the long lever:
    The rotary movement marks the marking needles with a marking distance of 5 mm over a length of 120 mm (25 markings)
  • Raise marking bar, take sample and immediately insert new sample


rupture elongation ISO 6892

determination Lu by means of caliper gauge

  • very usefull for parallel strips without heads!
  • If purchase of cost-intensive long-stroke extensometer does not seem advisable due to low sample volume, other methods must be used to determine rupture-elongation (standard-compliant). 
  • For critical applications, it is also sometimes necessary to measure the elongation at break in conventional way (e.g. if the specimen breaks near or outside the knifes of extensometer. Furthermore, manual measurement of elongation at break according to various standards is mandatory (ASTM / NADCAP / BS / API).

Procedure: To determine the elongation at break, the broken sample is placed on a (magnetic) plate and joined together. For easy counting, the counted segment distances are marked with a permanent marker and the Lu to be measured is found (L0 after sample elongation). Ideally, this measured value is determined with an electronic caliper gauge and transferred to the open field of the test software at the touch of a button.

The instrument is suitable for all sample forms at the same time: In the case of a flat test specimen with a parallel length of 120 mm, the marks are applied at a distance of 5 mm for a length of 120 mm (e.g. Lc of a non-proportional flat specimen / tensile specimen DIN 50125 - H 20 × 80