Stahlinstitut VDEh https://vdeh.de/en/standardisation/stahl-eisen-blaetter/stahl-eisen-pruefblaetter/ – 10.08.2026

Sheet No.

Title

Status

SEP 1220-1

Testing and Doc­u­ment­a­tion Guideline for the Join­ab­ility of thin sheet of steel – Part 1: General spe­cific­a­tions. 

This first part of the series of SEP 1220 spe­cific­a­tions contains general require­ments. It is meant as a basis for unified material char­ac­ter­iz­a­tion and shall stand­ardize the exchange of data between the mater­ials sup­pliers and cus­tomers.

Described are the char­ac­ter­iz­a­tion of the base mater­ials, location of sampling, general test con­di­tions, including recom­mend­a­tions for cyclic testing. The data format for data exchange of tests (data header) is explained in detail.

2^nd edition November 2024

SEP 1220-2

Testing and Doc­u­ment­a­tion Guideline for the Join­ab­ility of thin sheet of steel – Part 2: Res­ist­ance Spot Welding.

The test methods spe­cified in this Stahl-Eisen test spe­cific­a­tion (SEP) describe the pro­cedure to determine the suit­ab­ility of auto­motive steel sheets for joining via the process of res­ist­ance spot welding.

Described are testing scope and con­di­tions, determ­in­a­tion of quality limits, destructive and non-destructive testing, and doc­u­ment­a­tion of results. Example diagrams are given for testing and eval­u­ation of results.

2^nd edition November 2024

SEP 1220-3

Testing and Doc­u­ment­a­tion Guideline for the Join­ab­ility of thin sheet of steel – Part 3: Laser Beam Welding.

The test methods spe­cified in this Stahl-Eisen test spe­cific­a­tion (SEP) describe the pro­cedure to determine the suit­ab­ility of auto­motive steel sheets for joining via the process of laser beam welding.

Described are sample pre­par­a­tion, test con­di­tions, determ­in­a­tion of quality limits, the test pro­cedure itself (con­tinuous and stitched lap welds), destructive and non-destructive testing, as well as doc­u­ment­a­tion of results. Example diagrams are given for testing and example sheets for the eval­u­ation of results.

2^nd edition February 2025

SEP 1220-3
supplementary sheet

Sup­ple­mentary Sheet ‘Method to determine cold crack sus­cept­ib­ility of laser welded thin steel sheet’ to SEP 1220-3 ‘Test and doc­u­ment­a­tion guideline for the join­ab­ility of thin sheet of steel – Part 3 Laser beam welding’.

This sup­ple­mentary sheet to SEP 1220-3 describes a test method to determine the cold crack sus­cept­ib­ility of laser beam welded thin steel sheet (delayed cracking). It shall be applied together with SEP 1220-3.

Described are sample pre­par­a­tion, test con­di­tions, welding pro­cedure (full and partial pen­et­ra­tion), visual testing, and doc­u­ment­a­tion of results with example doc­u­ment­a­tion

1^st edition July 2026

SEP 1220-6

Test and doc­u­ment­a­tion guideline for the join­ab­ility of thin sheet of steel – Part 6: Adhesive Bonding.

The test methods spe­cified in this Stahl-Eisen test spe­cific­a­tion (SEP) describe the pro­cedure to determine the suit­ab­ility of auto­motive steel sheets for joining via the process of adhesive bonding (with struc­tural adhes­ives and anti-flutter adhes­ives). Described are sample pre­par­a­tion, quasi-static lap shear test, under­cut­ting cor­ro­sion testing and doc­u­ment­a­tion of results.

Sig­ni­ficant changes compared to the 1st edition are updating of the ref­er­ence adhes­ives and the number of tests of sandwich spe­ci­mens.

2^nd edition January 2026

SEP 1220-7

Testing and Doc­u­ment­a­tion Guideline for the Join­ab­ility of thin sheet of steel – Part 7: Pro­jec­tion welding of fasteners.

The test methods spe­cified in this Stahl-Eisen test spe­cific­a­tion (SEP) describe the pro­cedure to determine the suit­ab­ility of auto­motive steel sheets for joining via the process of pro­jec­tion welding.

Exem­plar­ic­ally, a nut with seg­mented pro­jec­tions is welded to a thin steel sheet.

Described are sample pre­par­a­tion, welding equip­ment and test con­di­tions, determ­in­a­tion of quality levels, the test pro­cedure itself (visual testing, thread engage­ment, weld nut set-down, push-out and pull-out testing, torque testing, metal­lo­graphy), as well as doc­u­ment­a­tion of results. Example diagrams are given for testing and example sheets for the eval­u­ation of results.

1^st edition October 2025

SEP 1220-10

Test and doc­u­ment­a­tion guideline for the join­ab­ility of thin sheet of steel – Part 10: Laser beam brazing.

The test methods spe­cified in this Stahl-Eisen test spe­cific­a­tion (SEP) describe the pro­cedure to determine the suit­ab­ility of auto­motive steel sheets for joining via the process of laser beam brazing.

Described are sample pre­par­a­tion, test con­di­tions, the determ­in­a­tion of quality levels, test methods (visual testing, tensile testing, metal­lo­graphy) , and doc­u­ment­a­tion of results with example doc­u­ment­a­tion sheets.

1^st edition June 2026

SEP 1245

Approval Process for Steel Sheets for Automotive Applications (Cold Forming)

In the framework of collaborative work between automotive and steel industries, for the introduction of newly developed steel grades into serial application in automotive production, phases of the material approval process were defined.

A material approval process shall be used to specify the necessary steps for qualification of new grades of thin steel sheets through to readiness for use in series (volume) production. In order to evaluate new steel grades regarding their fitness for use in automotive series production, a test matrix is provided for supplying a broad data base. The results of testing are necessary requirements for the approval of a steel grade by the customer (OEM).

Compared to the 1st edition 2011, the following changes have been made: Additional to the four phases, there is milestone SST series start. Source approval has been added.

2^nd edition October 2024

SEP 1680

Drawing time-tem­per­ature-trans­form­a­tion diagrams for ferrous alloys

A CCT diagram makes state­ments about the devel­op­ment of the micro­struc­ture of a steel during pro­cessing or heat treat­ment. This Stahl-Eisen test spe­cific­a­tion (SEP) contains guidelines for drawing such diagrams. The dif­ferent types of diagrams are described. Spe­cified are specimen selec­tion and pre­par­a­tion, test methods and inter­pret­a­tion of test results. An Annex provides dif­ferent example diagrams.

Compared to the 3rd edition the fol­lowing sig­ni­ficant changes are executed: This SEP is avail­able with English trans­la­tion for the first time. Atten­tion was paid to a clear present­a­tion, e.g. for form­a­tion.

4^th edition October 2024

SEP 1681

Guidelines for pre­par­a­tion, exe­cu­tion and eval­u­ation of dilato­metric trans­form­a­tion tests on iron alloys,

Dilato­metric testing allows to trace the phase trans­form­a­tions in ferrous alloys. This Stahl-Eisen test spe­cific­a­tion (SEP) contains guidelines for the pre­par­a­tion, exe­cu­tion and eval­u­ation of dilato­metric tests for ferrous alloys.

Described are taking of samples, the fab­ric­a­tion of dilato­meter spe­ci­mens and the welding of ther­moele­ments. Indic­a­tions for the exe­cu­tions contain the mounting of spe­ci­mens, furnace atmo­sphere, deform­a­tion of the spe­ci­mens and data recording, as well as regular checks of the equip­ment. The eval­u­ation of results and the doc­u­ment­a­tion is demon­strated with figures.

Compared to the 2^nd edition the fol­lowing sig­ni­ficant changes are executed: The contents were adapted and written more pre­cisely. Atten­tion was paid to a clear present­a­tion, e.g. for form­a­tion.

3^rd edition January 2025

SEP 1927

Ultra­sonic Immer­sion Testing Method for Determ­ining the Mac­ro­scopic Clean­li­ness Rate of Rolled or Forged Steel Bars.

This Stahl-Eisen test spe­cific­a­tion (SEP) applies to the auto­mated ultra­sonic immer­sion testing of appro­pri­ately prepared rolled or forged samples of steel for long products.

Described are agree­ments, per­sonnel qual­i­fic­a­tion, pre­par­a­tion of test spe­ci­mens, the test equip­ment and its inspec­tion, adjust­ment, sens­it­ivity classes, test volume, test pro­cedure, assess­ment and test report.

An example assess­ment is included.

Important change: Sens­it­ivity setting shall be carried out no more with a ref­er­ence block (cal­ib­ra­tion block), but with a sample of the test job.

3^rd edition December 2025

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