For the production of our screw threads, we mainly use the thread roll system (chipless cold forming).

The input material has a diameter equal to the flank diameter of the thread (the measure that shows the centre of the thread turn). Thus, by indenting a half thread plastically, the material can be pushed outward.  This increases the diameter of the thread and the latter increases without forming chips.

Here it is necessary to use drawn steel. As not all steel types are in stock in great quantities, we use the following types: 4.8, 5.8 and sometimes 8.8. For RVS this is AISI 304 and AISI 316.

The table hereunder gives an overview of the used diameters for the production of threads.

In case of cold forming without chips, the material of the product is plastically and durably formed by pressure. When rolling a profile, the material structure is not cut, like in chipping operations, but only relocated.

Hereunder you find an overview of the many advantages of cold forming without chipping

Economic advantages:

• Extremely short operation time;
• Less material is required because the end diameter of the material to be operated is equal to the flank diameter and not to the external diameter of the thread.

Technical advantages:

• High precision of the profile and of the pitch of the thread, whereby the pitch cannot drift because the thread is rolled by means of fixed moulds; 
• The thread has a high resistance;
• Under pressure mirror smooth polished threads;
• Great wear resistance and corrosion resistance;
• The rolling process creates a pressure system in the thread core which allows to produce the greatest reinforcement there. This significantly increases the carrying capacity in comparison with cut thread.

U-brackets according to DIN 3570 and standard versions in sizes M6x3/8” to M24x24” are always available. U-brackets are offered in electrolytic or galvanized steel, but also in RVS A2 or A4. For U-brackets that deviate from these sizes (till M36) you can call on our customisation. 

At Merofix, materials can obtain different surface treatments:

• Electrolytic galvanized according to EN-ISO-4042
• Thermic galvanized (hot dip) according to EN-ISO-1461
• Iso-appropriate or oversized