FAQ: Redressing CNC Tools

Why should you redress your CNC tools?

Sintered tools need to be redressed to keep them straight and true, to continue giving a perfect CNC polished finish.  Redressing your CNC tools helps you get the maximum life you can from the tool, whilst still giving the best performance.

What is the benefit of redressing tools?

CNC tools are made to be redressed.  The cost to redress tools is a fraction of the cost of purchasing a new tool, and keeping on top of tool wear helps keep polish wheels in good condition – therefore giving you the best possible final polished worktop.  Not only this, but due to the tools being consistently sharp, you can keep running them at optimum speed – which means less production time!

How long does it take to redress tools?

The process usually takes around 2 weeks.

How are tools redressed?

We label, pack and ship to Italy, where they are initially sandblasted.  They’re then mounted onto a very expensive EDM spark erosion machine, where the tools are spark eroded back to an original drawing shape, down to the lowest worn point on the tool.  They’re then measured on an optical laser machine before being labelled, packed and shipped back.

EDM spark erosion machine used for eroding the tool down to the original drawing shape

Where are tools redressed?

Here at Stonegate, we get our tools redressed in Italy, which is where the tools are originally manufactured.

What condition do they come back in?

Stonegate supplies tools with 4mm diamond on, but as a tool wears by about 0.5-1mm they become unusable.  When sent for redressing, the tool is EDM’d back to the lowest point (3mm thick diamond) and comes back looking like new!

Are they labelled?

Yes, all tools are clearly engraved once redressed to show which position it is.  This makes it very easy to identify which tool you are using in your sequence.

Are they measured when returned?

Yes, tools are measured very accurately prior to boxing up to 5 microns (0.0005mm) on a Zares measuring machine, which ties into our OPTIMO service if required.

Visible difference between before and after redressing

Can they be easily set up when returned?

As they are measured for concentricity and microscopic imperfections on a Zares machine before arriving back with you, set up is extremely fast and easy.  To make this even easier, you can use our OPTIMO service, where tools are set up on Tool Holders with measurements – then, it’s just a case of inputting measurements into the CNC machine, lining up the height and pressing go!

Can redress tools be incorporated into your OPTIMO system when returned?

Yes, this is by far the best way to go, and will give you the best life and speed going forward.  Usually, we recommend adding new polish wheels to a redress set of metal tools to make a complete refurbished set.

How often should I redress CNC tools?

Tools should be redressed every few hundred metres, depending on the tool and diameter.  For optimum life, we suggest redressing every 150m for 20mm diameter tools, and every 300m for 80mm diameter tools as a guide, however if the tools are predominantly used on engineered stone, they will need to be cleaned up more regularly than granite due to the build up of resin on the tools.  We also supply dressing sticks  for cleaning off the bond on the tool to expose more diamond.

How many times can I redress my CNC tools?

Usually, we suggest redressing tools up to 4 times, however this is dependant on how many metres tools have travelled.  The redress process erodes part of the sintered tool away to make it the correct shape again, so there is a finite number of times a sintered tool can be redressed.  This is contrary to common belief that redressing tools ‘adds diamond back on to the tool’.