Scheiben: Produktklasse A , ab Harte 300HV, vorzugswelse fur Sechskantschrauben und-muttern

This standard, together with DIN 125 Part 1, March 1990 edition, supersedes DIN 125, May 1968 edition.

In keeping with current practice in standards published by the International Organization for Standardization (ISO), a comma has been used throughout as the decimal marker.

Dimensions in mm

1 Scope and field of application

This standard specifies requirements for product grade A washers with a hardness of 300HV or more. The preferred application of these washers is in product grades A and B hexagon head bolt/hexagon nut assemblies, with widths across flats as specified in ISO 272.

2 Dimensions

Type A , with Internal, but no external chamfer Commercial sizes: 1,7 mm to 37 mm.

Type B, with Internal and external chamfers Commercial sizes: 5,3 mm to 165mm.

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Page 2 DIN 125 Part 2

4        Designation

Designation of a type A or B washer of nominal size 13 and hardness class 300 HV:

Washer DIN 125-13-300 HV

Where stainless steel washers are to be supplied, the steel grade as specified in DIN 267 Part 11 or the material number as specified in DIN 17440 shall be included in the designation:

Washer DIN 125-13-300HV –A2 or Washer DIN 125-13-300HV -1.4306

Where a particular washer type is desired (e.g. type A), the type symbol shall be included in the designation, e.g.:

Washer DIN 125-A13-300HV

The DIN 4000-3-1 tabular layout of article characteristics shall apply for washers complying with this standard.

Page 4 DIN 125 Part 2

Standards referred to

DIN 267 Part 9  Fasteners; technical delivery conditions; electroplated components

DIN 267 Part 11 Fasteners; technical delivery conditions; stainless and acid resistant steel components (with addenda to ISO 3506)

DIN 522       Metal washers; technical delivery conditions

DIN 4000 Part 3 Tabular layout of article characteristics for washers

DIN 17440     Stainless steel; technical delivery conditions for plate and sheet, hot rolled strip, wire rod, drawn wire, steel bars, forgings and semi-finished products

ISO 272        Fasteners; hexagon products; widths across flats

Previous editions

DIN Kr961:01.36, 10.37; DIN Kr963:01.36, 10.37; DIN 134:03.23, 10.36; DIN 125 Part 1:02.21, 12.21, 03.23; DIN 125:10.36, 05.43, 05.68.

Amendments

The following amendments have been made to the May 1968 edition.

a)    DIN 125 has been split up into two standards, Part 1 and Part 2, the reasons being given in the Explanatory notes.

b)    The title of the standard has been amended.

c)    The outside diameters for nominal sizes 2,7,6,4,8,4, and 10,5 have been changed.

d)    Nominal size 165 has been included.

e)    The clearance hole is now to be provided with a chamfer or radius.

f)    Limits of size have been given on the basis of the tolerances specified.

g)    Hardness class 300HV has been introduced.

h)    The technical delivery conditions have been revised.

i)    The standard has been editorially revised.

Explanatory notes

In the case of hexagon head bolts and hexagon socket head cap screws, the design of the underhead fillet within the area defined by the minimum bearing face diameter, d_{a ,} is at the manufacturer’s discretion. This may occasionally result in an interference between bolt / screw and washer where the latter has a clearance hole made to the fine series as specified in ISO 273. Normally, such interference will pose no problems since, when the assembly is tightened, the washer undergoes deformation resulting in the washer being moulded to fit the shape of the underhead fillet. If washers of greater hardness are used, there is the risk that the edge of the washer will cut into the fillet and thus damage it.

Taking this into account, the responsible ISO Committee, TC2, decided that the clearance hole edge should be provided with a chamfer or a radius to minimize the risk of such a damage. In line with this decision, the responsible technical committee in Germany deals with ‘soft’ and ‘hard’ washers in separate Parts of this standard to allow for the difference in performance of both washer types.

For washer sizes up to 37, the clearance hole diameter, outside diameter and washer thickness have been harmonized with the specifications given in the 1983 editions of ISO 7089 *) and ISO 7909*) where such were available. At present, these ISO Standards or their revised versions (currently being prepared ) cannot be adopted as DIN Standards since, in Germany, a considerably greater number of sizes is required than specified in the ISO Standards.

International Patent Classification

F16 B 43 / 00

*) Obtainable form Beuth Verlag GmbH (Auslandsnormenverkauf), BurggrafenstraBe 6, D-1000 Berlin 30.