There are countless different choices and options for cutting tools available on the market today. A huge variety of factors must be considered in order for you to choose the perfect tooling solution for your application. What material you’re working on, such as whether it is metal, plastic, timber, or composite, the functionality of the product you’re looking to produce, whether it has moving parts or tricky shapes, and the finish you want to leave once you’re done, smooth or rough, all factor in when it comes to choosing which tool you should use!
Trying to consider all of these factors can be overwhelming. Today at Prima Tooling we’re cutting through the noise with another of our blogs to help you make these decisions with no stress or hassle! This week we’ll be looking at directional cuts and breaking down the benefits and differences between upcuts and downcuts.
For those of you who haven’t come across these before, the terms “upcut” and “downcut” refer to the direction of the spiral, or helix, around the tip of a tool. The direction of this helix determines whether the flutes – grooves running up the length of the tool filling the spaces left by the helix – push chips of removed material up and away from the workpiece, or down and towards it. Alongside direction of cut, other factors affect the way in which a tool ejects excavated materials, such as the angle of the helix and the number of flutes.
The most common direction for the helix on drilling tools and end mills is an up-cut. This is usually the standard as the up-cut guides the removed chips up and away from the workpiece, allowing it to be ejected clear of the worksurface and without risk of clogging.
The standard upcut is perfectly suited for cutting thick, strong, and durable materials like solid hardwoods or ferrous and nonferrous metals. However, with thin, brittle, or fibrous materials like composites, plywood, and medium-density fibreboard (MDF), the inner material can be dragged upwards, distorting the finish. The up-cut can also leave a rough, splintered finish instead of the smooth professional surface you want on your finished piece.
The downcut, on the other hand, will push the workpiece downwards into the machine table. This is handy for holding the workpiece firmly in place, but also forces the excavated chips downwards towards the workpiece, which can cause issues extracting the chips, reduce the speed at which you are able to operate your tools, and cause cloggage.
Additionally, doubled-faced panels such as Melamine faced panels (MFC) which require a smooth finish on both sides may not be suitable for either an upcut or a downcut, as both options will leave one side rough and fibrous! A compression tool can help here, as its combination of up-cut and down-cut allows it to leave a clean finish and a chip-free edge on both top and bottom. Take a look at our PCD compression router cutters here!