Face Shields, Sneeze Guards, Machining Plastics and Acrylics

While we have found ourselves in the midst of a situation no one could have imagined we would ever be in, quite a few of our customers have to stepped up and contribution their production capacity and be a part of the solution to nationwide shortages of personal protection needs. For those volunteering their time and efforts, we commend you!

In this article we will highlight particular tools that may be needed in the production of urgent supplies. The common applications that we have seen among our customers has been for face shields and sneeze guards.

Parting Material for Face Shields

The material that we have found most common for the face shields is .02″(.51mm) PETG. Typically we would suggest a Polished O-Flute up-cut bit for most rigid plastic materials. The reason for this, is to get the plastic chips out of the cut so they won’t melt and form back to the material. However, when you cut material that is .5mm thin you have the risk of an up-cut bit pulling the material off the table. An alternative bit for this is a Straight O-Flute as it won’t have the tendency to pull the material off the table. Some CNC Machine have a “shoe” that is under the shroud that applies pressure on the material which in this case an up-cut can work. If there is no shoe and the material is very thin we recommend a Straight Polished O-Fute.

Should I go with 1 Flute or 2 Flute Bits?
Due to the nature of face shields, being typically sized 9″ x 9″ (with a radius on the corners) the machine has trouble getting to full speed before it reaches the next turn, so a single flute is a better choice. If the tool has 2 Flutes and is not moving through the material fast enough, the chip load will be too small, creating excess heat and cause melting.

Cutting Material for Sneeze Guards

Sneeze guards, which are commonly seen in use at grocery stores, banks and gas stations, are manufactured with a more rigid plastic and acrylic than the face shields. The most common thicknesses that we have encountered are 1/4″ and 3/8″. For machining these, a Polished Up-cut O-Flute router bit will work best.

Rounded Edge
Some customers have found that that it’s easiest to finish the edges with a Solid Carbide Rounding Edge Straight/Upcut Bit. The style of cut depends on how strong your material hold down is. We recommend a Straight O-Flute for weaker material hold down and Up-Cut for stronger material hold down.

We want to thank all the customer’s that are donating their time to provide resources to the healthcare industry, if we can provide any information to assist with the production of the live saving equipment please reach out 800.544.8436


At GDP|GUHDO, we have put our resources together to provide a comprehensive CNC Tooling Guide. This guide is designed to provide the knowledge to support the most efficient use of your CNC tooling.  We want to put the information into your hands any way that you can use it, so we also have a downloadable link to a PDF version of the presentation here.

Below is a directory for both the video presentation and the PDF presentation.

Topic Slide # Time
Introduction to CNC Tooling 1-7  0:00
Tool Holders and Clamping Systems 8-22  3:37
Drill Bits and Adapters 23-26  10:11
Sizing Jointing Rebates, Dado Cuts and Grooving 27-47 11:30
Other Common CNC Tooling 48-53 22:57
Material Specific Tooling 54-63  25:52
Profile and Custom Tooling 64-68 28:54
Saw Blade and Grooving Adapters 69-72  31:33
Other Tool Tips 73-80  32:32


Precision CNC Tool Holder Options

HSK Collet Chuck, Collet and Router Bit

HSK Collet Chuck, Collet and Router Bit

Standard HSK collet chucks are currently the most common in use in the woodworking industry. They are relatively inexpensive, and highly flexible due to the wide range of collet sizes that are available and easy to interchange.   While HSK style collet chucks are a good choice for most applications, the multiple parts involved in tool clamping (holder, collet and nut). this style chuck does not provide the tightest possible tolerances or clamping pressure. This is one of the shortcomings that has made thermal heat-shrink tool holders popular. 

Thermal (Heat Shrink) Collet Chuck

Thermal (Heat Shrink) Collet Chuck

Heat-shrink tool chucks have been gaining popularity due to the very tight tolerances (0.003mm / .00012″) and extreme clamping pressures used to hold tools in place.  They are balanced to 30.000 rpm.   These chucks offer a slim, light weight design with very high clamping power and accuracy. This choice of tool holder is ideal for use with insert tooling.  When using solid carbide or PCD (Polycrystalline Diamond) tooling, tool changes must be completed by the use of either an in-house heating element or sent out to an existing tool supplier.  Heat shrink chucks have their specific advantages, but they also have limitations.  Not all  diameters are readily available, the cost is higher than standard collet chucks and the additional cost of a heating element for in-house flexibility, without depending on a third party to remove the tool from the holder, can be considerable.

Hydro Chuck

Hydro Chuck

 Hydraulic tool holders are an often overlooked option to thermal tool holders with the same accuracy and more flexibility.  The hydraulic tool holder works by using fluid to compress an internal membrane within the tool holder. The hydraulic fluid delivers uniform pressure around the membrane allowing it to compress equally around the periphery of the cutting tool (shank) providing an even hold on the tool shank. The hydraulic fluid is activated by the use of a T-handle wrench to turn and activate a pressure screw. To release the pressure and cutting tool from the tool holder, simply turn the pressure screw counterclockwise. In addition to the quick set and release feature, here are a few additional benefits and features:

  •  Precise tool clamping tolerance of 0.00012”
  • Transmission of high torque or clamping pressure
  • Quick tool set up and removal
  • No Heating element or torque wrench required
  • Hydraulic fluid provides vibration absorbing features
  • Flexible with the availability of collet reducers
  • Increased tool performance (finish quality & tool life)

 With clamping tolerances that are comparable to heat shrink tool holders, tool changes are simple and quick. In addition, no heating element is required for tool changes. And, like standard collet tool holders, hydraulic tool holders provide the ability to use different shank tools by the use of high tolerance (collet) reducers.

The ease of use, high clamping tolerances and torque can and will benefit your bottom line by extending tool performance and improving finish output.

For additional information, please contact us!

What is Polycrystalline Diamond (PCD) Tooling?

PCD Saw Blade

PCD Saw Blade

In the right application, using PCD tooling can reduce your tooling cost significantly.  PCD (Polycrystalline Diamond) has been used in the wood/composites industry for over 35 years due to its abrasion resistant properties and hardness.  This synthetic cutting edge material was pioneered by General Electric’s Specialty Materials Division.  PCD is composed of diamond particles that are sintered with a metallic binder at extreme temperatures and pressures,  creating the hardest and one of the most abrasion resistant materials used in cutting tools. Tooling that utilizes this specialized material is now used in a wide range of machining applications including sawing, routing, drilling and profiling to maximize tool life and reduce production cost.  Ideal material applications include cutting chipboard, MDF, particle board, HDF,  and many composite materials including solid surface, fiberglass and phenolic.

PCD tooling

PCD Tooling in HSK 63F Collet Chucks

Like tungsten carbide, PCD is available in multiple quality grades. Most machine applications are supplied with standard quality grades with varying grain size. More demanding applications may be supplied with coarser grain or a “polished” tip.  Polished PCD helps prevent material buildup on the cutting surface (face) which improves tool performance due to less heat generating in the cut.  If you are considering using diamond tooling or if you have any questions concerning the feasibility of using polycrystalline diamond tooling, you can count on GUHDO to provide the guidance and knowledge to solve your most difficult machining applications, click here to contact us now.  In addition to delivery state-of-the-art PCD tools, we also sharpen PCD in-house at our facility in Marietta, GA.

PCD Radius Cutter

PCD Radius Cutter