Special raw materials and stainless steels
for high-quality connecting elements
We are a leading specialist for high-quality connecting elements made of various special materials and stainless steels. You will find materials with different properties in our assortment.
Our selection ranges from conventional A2 screws to connecting elements including threaded rods, washers and nuts made of materials that are highly resistant to corrosion. We currently have one of the largest warehouses for threaded rods in 1.4529, 1.4462 and 1.4571. We are more than happy to cut threaded bolts according to the requirements of our customers.
We offer the right stainless steel screws for every application.
Due to the new actualization of standards of ISO 3506-6:2020, the materials of CRC IV and CRC V on our stock are now also classified into the new steel grades A8, D8 and D6.
Conventional special materials always in stock
The most common and frequently required special materials such as A8 (1.4529 HCR), D8 (1.4410 Super Duplex), D6 (1.4462 DUPLEX), and A5 (1.4571), as well as the stainless steels A4 and A2, are available directly ex stock.
Our “king” among special materials is Alloy 926 (1.4529), which has a extremely high corrosion resistance amongst all austenitic stainless steels.
Super duplex steel 1.4410, which also offers an even higher strength, is also in the highest corrosion resistance class V. Just one level below duplex steel 1.4462 is to be found, which is classified in corrosion resistance class CRC IV. The third-highest level of our special materials is occupied by 1.4571 and the stainless steels 1.4401 and 1.4404. This means that you will find the right material for each of the five corrosion resistance classes (CRC) in our range – directly from stock.
For applications requiring stainless steel with proper acid and corrosion resistance in accordance with Class III, the titanium-stabilized material 1.4571 (A5) and the stainless steels 1.4401 and 1.4404 (A4) offer optimal solutions. It is not without reason that screws made of stainless steel A4 are used in many areas of fastening technology. The most commonly used stainless steel is A2, also known as AISI 304. This alloy type accounts for about one third of stainless-steel production. Screws made of A2 meet the corrosion resistance requirements of Class II and are typically used in wood screw connections, apparatus engineering or kitchen equipment.
Lots of other special materials with special properties
In addition to the standard special materials and screws made of A2, A4, 1.4571, 1.4462 DUPLEX, 1.4410 SUPERDUPLEX and 1.4529 HCR, we also supply lots of other special materials for special applications on request. Although you will not find them in our product catalogue, we will be more than happy to procure them on your behalf on a project-by-project basis. Our other special materials are divided into the following three groups:
- Heat-resistant special materials
- Super-duplex special materials
- High-alloy special materials
Materials such as 1.4828 and 1.4841 are characterized by their heat resistance. The materials for screws can be found in applications in the petrochemicals industry, waste incineration units or heat treatment units in the metal industry.
Super duplex steel is one of the most highly corrosion resistant materials available and is always used when conventional steels no longer meet the corrosion requirements. Super-alloy materials with brand names such as Hastelloy or Incoloy demonstrate high strength at high operating temperatures. Typical applications are in the high temperature range for engines, propulsion units or aerospace turbines.
Important alloying elements and microelements in stainless steels
What do the chemical elements molybdenum, sulphur, aluminium, chrome, niobium, carbon, silicon, copper, manganese, nickel, nitrogen, titanium, and vanadium have in common? They all are alloying elements and microelements of stainless steel.
But which effect does every single element have towards stainless steel and in which composition? Does the material become harder or more resistant against corrosion? Which influence do the elements have on the characteristics of the material? What does the effective sum W (or in English: PREN) declare and how is it determined?
You can find a compact summary about this topic here: Important alloying elements and microelements in stainless steels.
Choice of material according to corrosion resistance classes
Corrosion resistance classes (CRC) are of central importance for the selection of suitable materials. They can be divided into five different classes, depending on the basic elements used for the materials and the composition of the alloys. The classes determine the extent to which the connecting elements made of the materials fulfil the expectations for corrosion resistance in buildings. Architects, construction planners and engineers need to comply with the resistance classes when selecting and procuring the connecting elements. The material specified by the standard always needs to be selected depending on whether a stainless steel screw is used in an indoor pool, close to the sea or in a dry environment. Safety is of the highest priority here!
We deliver the desired fasteners in the required material – directly from stock!
The following pages provide you with more information about the properties of the different materials and the importance of corrosion resistance.
If you have any questions on this topic, do not hesitate to contact our expert staff by phone, web form or email.
They will be more than happy to provide you with detailed advice and find the right material for you.
Our Sales Team will be more than happy to help you further:
T: +49 7941 6073-0 sales@tobsteel.com