Quality has always been an integrated part of company policy. Not only concerning the technical aspects of the threaded rods, but also concerning the performance to our customers, and environmental issues relating to production and packaging.

Bodegraven Metaal n.v. is certified according to ISO 9002(1994) and 9001(2008) by TÜV. This guarantees full trace-ability for the qualities 8.8 and Stainless, these qualities can be supplied with certificates.



DIN 976-1

Threaded rods with metric thread

This norm describes the length tolerances, and a list of all other relevant norms.

ISO 898/1

Mechanical properties of fasteners made of carbon steel and alloy steel

This norm gives the properties for the grade indication of fasteners

EN ISO 4042

Electroplated coatings of fasteners

This norm states the different qualities of electroplating, and their properties.

DIN ISO 10684

Electroplated coatings of fasteners

This norm states the different qualities of electroplating, and their properties.

DIN ISO 3506-1

Corrosion-resistant stainless steel fasteners

This norm states the most popular kinds of stainless steel used for fasteners, and their properties.

NBN EN 10204

Metallic products- Type of inspection documents

This norm gives a view of the different kind of certificates, and what you can expect from them.

DIN 13-20

ISO metric thread.

General purpose ISO metric screw threads.

DIN ISO 68-1 

Screw threads - Basic profile 

DIN ISO 965-1 + DIN ISO 965-2

Tolerance system of metric thread.

This norm explains the working of the tolerance system for metric thread.

Surface treatments

We can supply our threaded rods with different surface
treatments, of which the following are the most common:


Self colour

Has no treatment.


Electroplated. (EN ISO 4042)

Is called Bright Zinc Plated (BZP) and is adding a thin layer of zinc through a electro/chemical
process. In general very thin (3-5 Mµ) and is for use indoors.


Hot dip galvanising (DIN ISO 10684)

Is adding a layer of zinc, by dipping it in a heated liquid zinc bath. This causes an alloy between

zinc and steel. This layer is a lot thicker (40-60Mµ) compared with electroplating. This can be used

outdoors, but, due to the process, the tolerances and straightness can cause some problems.


Delta Seal (Duplex)

Is a "duplex" system, meaning first a layer of BZP and then a top layer of Delta Seal. This gives a
lot higher corrosion resistance.

Colour Codes


The different qualities are marked with a colour code on the head of the threaded rods. This code

is followed by the majority of the European producers and distributors.




SS 304-A2

SS 316-A4


No colour code

Yellow (RAL 1021)

Green (RAL 6018)

Red (RAL 3000)

10.9   White (RAL 1013)