When considering spiral/helical cutterheads, it's important to take into account the number of carbide inserts they are equipped with. These cutterheads have short pieces of carbide inserts placed on them along helical grooves in a staggered pattern, which approach and cut materials in a continuous manner with divided kick-back. This is different from the direct tearout of whole HSS blades. Therefore, the number of carbide inserts on helical cutterheads is a significant factor that must be considered.
The combined cutting length of the carbide inserts is the individual edge length multiplied by the number of inserts. For example, some 8" bench top jointers come with segmented heads that have 16 pieces of carbide inserts at 14x14x2mm size. The combined length is 14x16=224mm. In comparison, Sheartak installs 24 carbide inserts at a size of 15x15x2.5mm. The combined cutting length is 15x24=280mm, which is a significant difference compared to the segmented head's 224mm.
Another example is the DeWalt DW735, which Sheartak and Byrd install 40 carbide inserts on four spirals. Other suppliers' cutterheads have only 30 or even 26 carbide inserts, which is a noticeable difference.
Similarly, Sheartak installs 80 carbide inserts on 15" planers, Byrd installs 75 inserts, while Lux has only 68 carbide inserts.
The number of inserts that is considered good depends on the frequency of machine operation. For heavy cutting and industrial use, it is recommended to have more inserts. However, for light use or hobbies, fewer inserts will suffice.
Spiral cutterheads with more inserts are certainly better than those with fewer inserts, even if they are offered at the same price.
It's essential to focus on the details of the cutterheads and not just their prices. It's recommended to talk with tool experts and not be misled by fancy advertisements or contents of paid articles.
