Cost Comparison – Inserts vs. Solid Carbide Bits

We’ve had some interest around how the costs break down in our last post,  “Increase Productivity with Insert Compression Router Tooling”.  Here is an example using the same 6243 series (PN#6243.029.34 with insert#6243.295.00) two flute compression style insert router bit for comparison against a solid carbide two flute compression spiral (PN#6229.750.20M) to see how the costs stack up.   As you can see from the following chart the breakeven payoff for using insert tooling comes at around 45K linear feet machined. The difference in tooling cost becomes more noticeable at around 100K  linear feet machined where the cost of tooling is reduced by >50%!

Total Cost of Tooling - Inserts vs Carbide

Total Cost of Tooling – Inserts (Red) vs Carbide (Blue)


If large diameter router bits (3/4″ +) is used in your cutting application, it’s important to assess the cost savings that can be achieved by using insert over solid carbide tooling.  With solid carbide bits, you must continually purchase new tools as they can only be sharpened 2 or 3 times.   In addition, often the tool life, after sharpening, is reduced to 70-80% of original tool life,  due to decreased rake angles.   Finally, after sharpening you need to compensate for the diameter change that occurred as a result of sharpening.

6243 Series Insert Compression Bit

6243 Series Insert Compression Bit


One of the biggest advantages of using carbide insert tooling is that you pay for the tool body one time and often get two cycles out of the same insert since the insert is often reversible.   Keeping just a box of replacement inserts on hand saves tying up cash in spare tools on the shelf.  The benefits of insert tooling, unfortunately, are not available for smaller diameter tools (such as 3/8 or 1/2″)  as they cannot be constructed in 2 flute or shear design due to space limitations on the tool body.   If you are interested in ways that you can reduce your total cost of tooling you can contact us now for more information. We also have a full service sharpening and insert grinding center with quick turn around times.

HSK Calibration Arbor

CNC Calibration Arbor - HSK63F

CNC Calibration Arbor – HSK63F

Within the CNC Machining universe the HSK calibration arbor goes by many different names including the spindle run-out arbor, calibration arbor, runout test bars, spindle taper test bar and test arbor.  These integral maintenance tools offer a quick and easy way to test your CNC machine for accuracy and alignment after a crash, machine installation or relocation or simply as a periodic performance test.

The calibration arbor helps identify excessive slop or axial play early on, a factor that will greatly reduce machine performance and lead to excessive tool wear and breakage. Regular spindle inspection and calibration will ultimately reduce downtime and prevent costly repairs of the machine tool spindle and related bearings over the long term.

The GUHDO Precision Calibration Bar (Part# 6375.300.00 ) is available in all standard HSK-A, HSK-C,  and HSK63F as well as SK/ISO/BT models and are case-hardened and manufactured in Germany in accordance with strict European Standard  production specifications. Runout of less than 0.005mm at test bar nose and run out of less than 0.016mm on the test bar diameter are guaranteed.  For more information please give us a call at 1-800-544-8436 or contact us on our main website.


Is your CNC Machine burning material or bits?

Here are some bits our clients sent in for repair.

PCD (diamond) bits our clients sent in for repair

Have you ever experienced smoke or even worse burning during the routing process and wondered why this is happening? While friction is the cause of the problem, the root cause can be harder to identify. Feed rates, rotation speed, halts in momentum and a variety of other factors can all contribute to creating the excess friction that can destroy your bit or workpiece. This is not something we can simply ignore as burning affects the tool life, machine condition and even puts your shop at risk! Choosing the right bit for the job can help reduce some of the factors around excavating shavings at a sufficient rate. Additionally, tools like the Cyclone will help with dust/chip evacuation.   The right balance must be struck between tool design and performance expectations as well as motor speed and feed rate.  Incorrect chip load for the material being machined is the primary cause of burning bits. Halts in momentum in places like inside corners are also prone to burning due to the CNC slowing momentarily and thereby recutting chips that would have otherwise already been extracted from the cut. This is a key concern in the CNC programming of the tool path and shouldn’t be overlooked. Some bits are designed to ramp plunge only, so a straight axial descent into the material will cause burning as well. Realistically, no matter what you do, bits have a limited life span even in normal conditions and the more abrasive the material, the quicker the wear . Hard materials and abrasive composites consume bits at a much higher rate than less abrasive materials. The correct tool selection for your application, coupled with material being cut under the correct chip load will have the largest impact on your tool life.  Another consideration, when applicable, is using PCD tooling over solid carbide in many cases. Have questions? Contact us today (or 1-800-544-8436) and we’ll ensure you have the right bit for the job!

How to Ensure your Tools are Safely Clamped in the Tool Holder

Over-tightening your collet nut can lead to collet distortion, tool runout and breakage, while not tightening enough can lead to tool slippage or worse. The best solution to avoid either scenario is to use a torque wrench which will provide an accurate torque measurement when tightening the collet nut.

Torque Wrench

Torque Wrench

The torque wrench consists of a spanner wrench handle and collet key that correlates to the collet style being used. The appropriate clamping torque recommendations for the most popular collets used in wood and plastics machining are as follows:

  • RDO35 (SYOZ25) collets 90ft/lbs
  • ER 32 collets 100 ft/lbs
  • ER 40 collets 130 ft/lbs

For more information on tool holder you might want to check out this article on the importance of using a ball bearing collet nut.  All GUHDO tool holders are bi-directional and they come with a ball bearing collet nut standard. Contact us now for more information.