To speak to some tradespeople it would seem that the most important thing about a diamond cutting disc is the price. Not the materials it was designed for cutting, not safety, not speed of cut nor the amount of noise it made. Now I am definitely keen on getting value for money, but I am also keenly aware of my safety and my time. However, I do get a sense of satisfaction when I get a tradesperson come up and ask about a particular piece of kit and I am able to make the point that good kit, used well, can be safer and quicker, thus saving time and money, as well as making for happier clients.
Of course there is the sharp intake of breath when I tell them, for example, that my rail saw cost £500, but the message remains that sometimes, its not all about the price you pay – sometimes the bottom line needs a bit more sophistication when being calculated. It can be a case of penny wise but pound foolish. Diamond cutting discs are squarely in the area of you “get what you pay for”. There are literally dozens of makes of cheap diamond discs on the market. They all vary enough in appearance and packaging for you to be vaguely able to tell the difference so that you can find them again. But my argument is that a good quality diamond disc, chosen with the job in mind, is more likely to perform well, save you time and minimise wear and tear on your disc
Enter the two diamond discs sent by major abrasives company, Klingspor. Established in Germany in 1893 by Johan Friedrich Klingspor to make a variety of abrasives, the company was behind the development of abrasive cut-off wheels and grinding discs in the 1950s and 60s. With manufacturing facilities in Europe, the US and Mexico, the company is one of the four largest abrasives companies in the world and produces a huge range of abrasives of many types – hence it has a lot riding on getting its products right both in terms of price and performance. Klingspor makes a point of providing discs at three price points (good, better, best) to meet the needs of customers’ varying needs and its in-house R and D facility in Germany offers continuous review, development and improvement of its products.
ALL of Klingspor’s diamond discs are Organisation for the Safety of Abrasives (oSa) accredited – the highest level of safety accreditation available. I was sent two mid-range discs for review, a DT600U and a DT600AB. The DT600U is so designated because it is a mid-priced universal blade meant to be used on pretty well all construction materials from natural stone, to reinforced concrete and all stations in between. This blade has proved to be very successful in the market – not only because of its pricing but also because of its design – a design that makes for rapid cutting as well as a long disc life.
Aimed at: depending on the grade all the way up to demanding professionals
Pros: Made in Europe OSA approved for safety and ingenious design makes for good cutting
Now normally, these two features would work against each other. Long disc life usually means having a slightly thicker blade and deeper segmentation of the blade. On the other hand, a thinner blade usually means a quicker cut because there is not so much dust to remove from the thinner kerf, but the thinner blade then wears more quickly. You can also make a blade last longer by making deeper segments, but that brings other issues into play like the safety of the weld of the segments onto the disc. What Klingspor has managed to do with this blade is to strike the correct compromise between thickness and wear and the secret of this is in the design of the segments. This 300mm diameter disc has 32 segments squeezed onto its rim. Each individual segment is
10mm deep and it has 25mm deep gullets that are wider at the bottom, that slim down a bit before ending in a precisely drilled hole for reducing noise.
The wider slot at the bottom allows dust to be shifted quickly from the cut. A look through a magnifier reveals a fairly close, but random, distribution of diamonds on the segments, but if you think that more diamonds always equals faster cutting, then you are wrong. You may not get optimum cutting if too many diamonds produce too much dust to shift from the cut and then cause clogging. But the key design feature is the number of segments on the rim – 32 segments with regular slots to disperse the waste quickly has proved to make a blade that not only cuts quickly, but lasts well too. By the end of my tests on steel, concrete, marble and bricks, I could barely see any sign of wear on the rim at all, promising a longer life – I still expect to be using this blade in a few month’s time.
The DT600AB disc is a more specialised design for use largely on concrete and asphalt and has been a hit with utilities, road repair contractors and general construction firms. The one thing that is very obvious when looking at the segments of this blade is that the diamond distribution is much closer than the DT600U.
The diamonds are also coated in titanium powder for maximum adhesion as asphalt and concrete are very aggressive and tend to tear away diamonds that are not tightly bonded. With eighteen larger segments and much larger open–ended gullets cut into the rim, it is clear that dust removal is one of the main aims of this design. Nothing for it but to mount it on the machine and try it out on some concrete and asphalt. Fortunately, I have a small asphalted area where I park my car, and I was struck by just how
“clingy” asphalt can be when cutting, as the heat melts the tar and sort of gums it up. But the big gullets do their job and cutting is quite quick – if you are not careful you can go too deep quite quickly. Concrete is a doddle with this disc, no wonder road repair firms are buying it – it is perfect for cutting kerbstones. I know I had a relatively short time of testing, but the wear on the disc at the end was very small, meaning that I can use the disc on other jobs…. In the end, quality always wins out for me – I have proved to myself again and again that you get what you pay for. These Klingspor diamond discs, tick lots of boxes and I will certainly keep an eye out for them when I have worn these ones out.