Learn how to look for signs of cutting tool wear
Cutting tool wear and tool breaks can create real production and performance headaches. David Magnall, Seco Tools (UK)’s Business Development Manager – Products, explains how manufacturers can tell when its time to change tools.
'A cutting tool’s edge has a hard life – because the edge is where all the action takes place.
'Different work-piece materials and different cutting conditions mean that a cutting edge is literally being attacked from all sides and has to cope with a great deal of hostility namely changing mechanical loads... chemical attacks and thermodynamic assaults.
'OK – modern cutting materials like Seco’s Duratomic coated carbide grades combined with the correct tool geometries can withstand everything that’s thrown at them – but even these will wear out over time.
'Back in the day cutting tool wear was easier to observe and was mainly confined to flank and crater wear. The wearing process could be followed and even anticipated enabling the operator to intervene, stop the cutting process and change the cutting edge.
'Today this is much more difficult to see or gauge.
'A cutting edge can look new and wear free for a long time...and then suddenly it will break causing downtime and/or damaged parts. Both need to be avoided and can be for those manufacturers able to spot the warning signs.
'Understanding tool wear and its causes are fundamental in controlling and adapting the cutting process.
'Such understanding will help manufacturers make strategic decisions and modify the input conditions – tool selection, machining strategies etc, in order to achieve the outputs and results required – higher productivity, reduced costs, improved process reliability etc.
'The trick with cutting edge breakage is to be able to stop machining just before the break occurs but, if this is maybe cutting it a bit-too-fine, there are tell-tale signs that can help manufacturers intervene at the optimum time.
'Specific signs can include the creation of a ‘grey zone’ appearing on the cutting edge...or a subtle chipping or crumbling of the cutting edge. Or even the slight change in shape and colour of the chips.
'Watching out for these signs (and using, for example, a small tool wear magnifying glass), will alert manufacturers when the edge is on its last legs and that it’s time to change.
'Owing to the many different materials being machined these days Seco, through its STEP (Seco Technical Education Programme), has developed an in-depth training module where cutting tool wear, using different work-piece materials, are covered - thereby enabling manufacturers to be better aware and informed about what to expect and what signs to look out for .
'With so many difficult challenges confronting precision component manufacturers these days - tool wear shouldn’t be one of them – and needn’t be with Seco’s assistance and intervention.”