Diamond v. Carbide : Weighing the Costs and Benefits

PCD tooling Under the right conditions and with proper maintenance and handling, significant cost savings can be achieved by running polycrystalline diamond (PCD) tooling.   Understanding the basics of diamond tooling is important when contemplating its use in your own production line.  First and foremost, think of it as the marathon runner, as it will yield the best results in continuous and steady cutting of homogeneous materials.  Diamond tooling is not advisable as an all-round tool that will be required to meet demands of a wide range of cutting applications on a day to day basis.  So, if you are machining different materials and want one tool to do it all, the diamond tool will not be able to excel as well as it will if you are machining, for instance, 3/4″ MDF all day long.

Polycrystalline diamond is manufactured in a high-pressure, high-temperature laboratory process that fuses diamond particles onto a carbide substrate, which, in turn, allows the diamond to be brazed onto a tool body.  PCD has an exceptionally high wear resistance factor, in particular with abrasive composite materials that are often difficult to machine with carbide.  Examples are:  particleboard, MDF, OSB, high pressure laminate, phenolic, fibre glass etc.  Depending on what material is being machined, it is not unheard of for a diamond tool to outrun carbide by a ratio of 300 : 1!  Nevertheless, when deciding whether to switch, be conservative in your cost analysis and base your decision on the diamond bit lasting 25x longer than carbide.  You won’t be disappointed!

The original developers of synthetic diamond were GE (Specialty Materials Division) and DeBeers  (Element 6) who pioneered this process and mastered the know-how of synthesizing diamond for industrial cutting applications.  Meanwhile, there are a number of synthetic diamond tool blank manufacturers, and the quality, durability and wear resistance is not always equal.

When shopping for a PCD tool, it is important to discuss your proposed use and expectations in detail with the tool manufacturer as this allows for selection of the proper PCD grade (grain size), and optimum tool design.  In particular,  you want to be certain that there is no more PCD on the tool than actually needed (i.e. don’t order a tool with 1.1/4″ cut length when you only cut 3/4″ material because that needlessly increases the tool cost.

To understand the complete picture and compare “apples to apples” when shopping, it is important to ask the following questions:
How many times will I be able to sharpen this tool under normal wear conditions?
What will it cost to sharpen this tool?
How long will it take to turnaround a tool when sharpening?

If you neglect to get answers to these questions,  you might be in for a surprise to find you were sold a “disposable” tool that cannot be sharpened at all, or can only be sharpened once.  Or, you might think you are getting a bargain when you buy the tool, only to find you are going to be expected to pay 50% of the new tool cost to get it sharpened.

These factors significantly affect the cost per linear foot machined so are important to know when doing a cost comparison or justification for PCD tooling.  Below is an example of a cost comparison using a diamond saw blade versus a carbide tipped blade:

Screen shot 2012-12-04 at 11.59.11 AMcost per linear foot formulaScreen shot 2012-12-04 at 1.01.11 PM

$.0028/$.0143 = PCD costs 19.6% of carbide when comparing $/Linear Foot (80.4% cost reduction) 

Another advantage of PCD tooling, apart from the longer tool life,  includes the quality of finish which is often significantly improved and therefore requires less sanding.  With carbide tools, the finish starts to deteriorate from the very first cut onward, whereas the diamond tool maintains a nice clean finish right up until it becomes dull…..at which time it plummets and should be pulled for sharpening.  Pushing a diamond tool to run a little longer once it shows signs of becoming dull  (a good indicator is when the machine amps increase), can result in a substantially larger sharpening cost as the diamond face can shatter and require re-tipping/replacing of the cutting edge.

At first glance PCD tooling seems expensive when compared to carbide however when we compute the cost per linear foot machined, in the right application, PCD will be revealed as the only choice for discerning shops that are cost conscious.  As you can see from the cost calculation above, the investment in PCD tools pays off rather quickly. Some of the top PCD applications are machining abrasive materials, composites and workflows that do high volume of the same cut and material type.

With PCD router bits, maintaining correct chip load is very important as heat buildup during the cut will damage the diamond and can lead to tool failure.  Accurate tool clamping systems with close tolerances are also essential as is firm material hold down to avoid any vibration during the cut.   For specific questions about PCD tooling, please contact us or give us a call at 1-800-544-8436

The Continuing Evolution of Diamond (PCD) Cutting Tools

surface and panelAs published in Q2 2014 issue of “Surface and Panel” magazine:

The Continuing Evolution of Diamond (PCD) Cutting Tools:

In the summer of 1982, when the International Woodworking Fair (IWF) made its debut show in Atlanta, GA, the first polycrystalline diamond tools for wood/composite material were introduced in the U.S. The promise they brought ….to run up to one million feet of material without a single tool change, seemed inconceivable and no one could fathom that any cutting tool could continuously run the equivalent of 7+ marathons (over 180 miles) cutting abrasive particleboard without wearing out on the first 10 miles!

High-tech panel production equipment coupled with competition among cutting tool manufacturers has earned a handsome dividend for panel processorsgiga cutter, allowing manufacturing costs to stabilize. As diamond tooling evolves, developments include extreme axial shear angle cutters that achieve a satin smooth finish resulting from a cutting action that is closer to shaving or peeling, rather than cutting. While these cutters are ideal for peripheral cuts, they aren’t the solution for parting cuts due to the larger cutting diameter necessitated by the extreme axial shear and resulting yield inefficiencies.

Hogging/panel sizing cutters continue to advance with interesting designs that incorporate dust flow and chip extraction features along with lighter overall tool weight (to reduce injury risk during tool changes) and tooth geometries that are matched to specific application for best finish.

The continuing advancement of newer composite panel materials, whether lightweight honeycomb panels with aluminum skin, wood composite panels with highly abrasive laminate surface, fire rated MDF, carbon fiber reinforced plastics, phenolics or other PCD Hoggerspecialty materials, each seem to present their own set of unique challenges to efficiently cut, profile and optimize tool life while obtaining a quality surface finish. These challenges keep design and implementation of new cutting tool engineering ideas at the forefront and this trend will continue.

Diamond-tipped saw blades deliver great savings during the many months they run without garnering even a moment of attention until they become dull! PCD saw blades do best and perform the longest in homogeneous materials, such as solid surface material, wallboard, hardboard, cement fiber board, MDF and similar materials.

FourcutDiamond router bits have progressed as well. Chip load is the most important factor in seeing positive performance, so, the once popular disposable diamond router bit, that has definite feed speed limitations, has taken back seat to newer designs. It is important to review expectations for output, finish and performance when determining the tool specifications. The choice of single, two or three flute, straight or shear, segmented, staggered, insert or solid PCD tip, diamond grade (coarse or fine), polished or not should all play a part in the decision for best results.

Drill bitsPCD2V, both through-hole (V-Point) and dowel style, are another relative newcomer in the array of diamond tools offered. While they do not run the marathons that their hogger, saw blade and routing counterparts are known for, they still offer a stately price/performance ratio that should not be underestimated or overlooked.

To summarize, panel processors not using diamond tooling in their production, are overlooking a tremendous opportunity to improve their bottom line! Letting the initial cost of diamond tooling intimidate…is ignoring the fact that in most cases, PCD provides the lowest cost per linear foot machined!

Written by Karin Deutschler, President of GUHDO USA Inc. Karin has been selling diamond tooling since its introduction in the U.S. in 1982.

 GUHDO now offer select precision tooling online or you can also check out our full catalog here!

The Safety of Cutting Tools

DSC_0021American woodworkers do not enjoy quite the same protections that European woodworkers do. Working with cutting tools is serious business and quite apart from the basics, such as wearing eye protection, using saw guards and other common sense precautions, there is no U.S. standard norm that dictates safety features in the manufacture of a cutting tool itself. So, when buying a cutting tool you are really at the mercy of the manufacturer and can only hope they know at what point the risk is too high and the request to quote or make must be turned down.

The first and most important consideration in the design of a cutting tool is safety. A poorly designed tool can result in catastrophic accidents that can maim someone permanently.

In Germany, for instance, anyone engaged in the manufacture of cutting tools is required to know the rules and to adhere to them at all times. According to the Accident Prevention Directives of the Association of Woodworking Careers which is the oversight authority for the industry workers (Holzberufsgenossenschaft), the employer must have all cutting tools made, serviced and assembled by competent individuals, i.e. an individual who, based on his/her trade, education and experience has sufficient knowledge in the area of tool maintenance, worker safety standards, accident prevention rules and is familiar with the technical aspects that he/she can accurately judge the condition of any cutting tool for its safe operation.

Tool marking requirements, such as exhibiting maximum allowable rpm of the tool and rotation indicators are great examples of very basic safety directives that are not required in the US and are generally absent on tools manufactured in North America. Another example is re-tipping saw blades. In general, by the time a carbide saw blade has run its course of 7 to 10 sharpenings, the saw plate is fatigued and ready for retirement. You could compare this to a marathon runner. Re-tipping a saw blade, would be like meeting a Marathon runner at the finish line, giving him/her a new pair of shoes and say “do another Marathon!”. The folks who support the argument of re-tipping a blade are doing so out of a lack of understanding how big a role the integrity of the saw plate itself plays in cutting performance and tool life.
An employer who allows his blades to be re-tipped is running an enormous financial liability risk. Imagine a tip came off a newly re-tipped blade and hits the saw operator? The manufacturers warranty and insurance will be void, and the saw shop is often not much more than a one-man shop. Often the small service shops don’t even carry liability insurance.

It is not unusual to see cutting tools in U.S. woodworking plants that would not meet European Safety Standards for safe operation. There are relationships between shank diameter and overall diameter (on router bits), and cutter or saw diameter versus arbor diameter that cannot be overridden. Bottom line is, when it comes to cutting tools don’t take any chances and know who you are dealing with!
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