Machining leadfree brass

Autore: Lemtec

Data di modifica: November 8, 2021

truciolo ottone
LEM TEC Machines for the Industry 4.0

Lead has always been added to brass alloys to facilitate processing and in particular to improve cutting, create excellent chip breaking and reduce tool wear. In recent years, however, lead reduction has become a priority for environmental and public health reasons.

The new European directive on drinking water called DWD (Drinking Water Directive), effective from 12 January 2021, introduces the minimum requirements for materials that are in contact with water intended for human consumption throughout the EU.

Each EEC  Member will have 2 years to review its national legislation and adapt to the new rules.

What does it mean for us in detail?

As far as we are concerned, in sectors such as taps, fittings, valves and more, where there is direct contact with water, the ‘absence’ of lead in the materials used will be required.

In other words, your machine tools will have to be suitable for lead free brass processing.

From a technical point of view, as we all know, the processing of brass such as CW614N (one of the most common leaded brass alloys) has always been considered relatively simple.

For example, there is no formation of coils on the tools as the chip is short and no extra spindle power is required to carry out during standard brass machining.

The issues of leadfree brass!

We cannot generally say the same thing about the various lead-free brass alloys already on the market in terms of burr formation, shear forces and shear strength.

If you thought of operating with the same machines you used before, you will know and have certainly encountered problems you are impressed to see a very long / pasty chip.

This situation, as you know, leads to the locking of the tools and to the clear demand for greater power and rigidity of the machine. Additionally, some of these lead-free alloys can be more problematic than others, so it’s also important to consider which lead-free alloy you are going to work with.

Some tips and recommendations

Tip number one, always specify the type of lead-free brass you want to use.

Therefore, once the lead has been removed from the brass alloy, the material is generally more complicated to work, unstable and, the traditional machines used up to that moment are almost out of action due to insufficient power to the engines. The cycle times will be very different.

For this reason, if you have decided to anticipate the times or have already changed the production to these new materials following the new regulations and market needs, we recommend that you avoid using rules and techniques designed for traditional brass. We are dealing with new materials for which LEM TEC is able to provide you with the most suitable solution, allowing you to optimize your process again. Cycle times will never be the same again. Of course, each case must be evaluated separately and if you would like more information, do not hesitate to contact us.

Goodbye and we hope to speak to you soon!