September 5, 2014 / best practices, blade life, continuous improvement, Cost Management, cost per cut, LIT, operations, preventative maintenance, productivity, quality
When it comes to selecting the right metal-cutting tools, most managers focus on two main features—performance and cost. In fact, most forward-thinking managers would probably even agree to spending a little more on a blade if it could clearly outperform others on the market.
However, what many managers fail to see is that the value of a blade goes far beyond its cutting time or its price tag. The real value is in the blade life. This is especially true in service centers, where managers are trying to balance tight delivery schedules with high variability. There is just no time to constantly change out blades. As this article from Forward magazine describes, a growing number of service centers are starting to measure overall equipment effectiveness (OEE) to gauge the availability, performance, and yield of their equipment, and blade life can play a key role in optimizing equipment.
Put simply: blade life matters. It affects your productivity, your cost, and your quality.
While advancements in tooth geometries and materials have certainly helped extend blade life, how your operators care for your blades is what really helps you get the most bang for your buck. Below are some tooling tips managers can apply to optimize their blade life:
- Running the blades at the proper speed settings is critical to achieving long blade life. In most cases, faster is not always better. Increasing the cutting speed of a blade may produce more pieces per hour, but it drastically reduces blade life. Band speed is restricted by the machinability of the material and ultimately heat produced by the cutting action. Too high of a band speed or very hard metals produce excessive heat, which has a negative impact on blade life. This not only increases your tooling costs, it creates bottlenecks and decreases cut quality. This could also result in excess scrap and rework—both of which directly impact your bottom line.
- Lubrication is essential for long blade life and economical cutting. Properly applied to the shear zone, lubricant substantially reduces heat and produces good chip flow up the face of the tooth. Without lubrication, excessive friction can produce heat high enough to weld the chip to the tooth. This slows down the cutting action, requires more energy to shear the material and can cause tooth chipping or stripping which can destroy the blade. Unfortunately, many operators fail to perform basic fluid maintenance because they don’t fully understand how lubrication can affect cut quality and costs. For a great resource on metal-cutting fluids, check out this video from the Society of Manufacturing Engineers.
- It pays to break in blades. A new band saw blade has razor sharp tooth tips, and in order to withstand the cutting pressures used in band sawing, tooth tips should be honed to form a micro-fine radius. Failure to perform this honing will cause microscopic damage to the tips of the teeth, resulting in reduced blade life and poor-quality cuts. Based on the results of our industry benchmark study, breaking in band-saw blades is a best practice among service centers and other industrial metal-cutting companies. According to the study, 45 percent of organizations surveyed reported they “always” break in blades, and 30 percent said they do it “most of the time.” But here’s the real nugget: 70 percent of organizations that report their scrap and rework costs are less than five percent also say they “always” break in their band saw blades. By breaking in blades properly, organizations are able to reduce “soft” failure that leads to waste and scrap, and, in turn, eats into their bottom line. While breaking in a blade may seem tedious, managers and experienced operators know that it pays off in the long run.