The original cutterhead on the Magnum Industrial MI-31170 13" Planer features 26 two-edged carbide cutters. These straight-edged inserts are positioned square to the feed direction, making direct cuts on the board.
Sheartak has developed a helical cutterhead for this planer, upgrading it with 39 carbide cutters, each featuring four indexable edges. Unlike traditional straight inserts, these carbide inserts are set at a slight angle to the feed direction, creating a shear cut. This significantly reduces tear-out and enhances the surface finish, especially on softwood and highly figured hardwood. Additionally, it dramatically lowers operation noise.
When an edge becomes dull or nicked, simply rotate the insert 90 degrees to expose a fresh cutting edge. The inexpensive carbide inserts only need replacement after all four edges have been used—eliminating the need for sharpening and minimizing downtime.
Sheartak’s spiral cutterheads reduce sanding work by up to 75% and consume less power. They also generate short chips in a staggered pattern, preventing dust buildup at the hood port and improving dust extraction efficiency.
An added benefit of Sheartak’s design is the V-pattern insert arrangement, which provides symmetrical cutting forces, ensuring smooth and straight board feeding.
With these advantages, Sheartak’s spiral cutterheads quickly pay for themselves through improved efficiency and reduced maintenance.
Spiral Cutterhead Kit Includes:
- High-tensile strength alloy steel cutter block
- 39 pre-installed carbide inserts
- A pair of Japan-made sealed bearings for lifetime use
- 5 additional carbide inserts and 5 extra screws as spare parts (free)
- 1 Wrench
Do I need to replace the original bearings?
If the bearings in your machine are in good condition, they can be reused by carefully removing them with a bearing or pulley puller. However, if the bearings are tightly pressed onto the shaft, removal may cause damage. To minimize this risk, we recommend replacing old bearings with our greased and sealed bearings, designed for long-lasting performance. For a smooth upgrade, we suggest adding the bearings to your shopping cart before completing your purchase.
We provide premium bearings from NSK, SKF, NTN, FAG, Timken. They are renowned for their high quality and performance, designed to provide durability and reliability in various applications
If you add the bearings to your order, we will preinstall them for you when premounting is possible, saving you the hassle of doing it yourself.
Do I need to to Add a Few Boxes of Carbide Inserts
We provide 5 carbide inserts and 5 screws as spare parts. However, many of our customers choose to purchase additional boxes, as the shipping costs for separate purchases can make it less economical.
Do I need a Torque Wrench?
To securely lock the carbide inserts, we recommend applying a torque of 48 to 52 Pound-Inches (or 5.42 to 5.88 Newton-Meters). (Note: 1 Newton-Meter is equal to 8.851 Pound-Inches, and 1 Pound-Inch is approximately 0.113 Newton-Meters.) It is crucial not to apply excessive torque, as this could cause the carbide inserts to crack or explode. On the other hand, using too little torque may result in the inserts not being properly secured, which could lead to cracks, shattering, or uneven height on the cutter block, causing ridges or lines on the board.
If one person is responsible for maintaining the machine, they can typically apply the same torque consistently without a torque wrench. However, when multiple people are involved in machine maintenance, ensuring uniform torque application can be challenging. For consistency and peace of mind, we recommend using a torque wrench.
What kind of steel the cutter block is made of?
The cutter block is constructed using GB/T 40Cr, a structural alloy steel of the same caliber as ASTM grade 5140, AISI 5140, SAE 5140, DIN 41Cr4, BS 41Cr4, JIS SCr440, and EN 41Cr4.The primary components of this steel are as follows: carbon (C) at a range of 0.37-0.44%, silicon (Si) between 0.17-0.37%, manganese (Mn) within 0.50-0.80%, and chromium (Cr) from 0.80-1.10%.
In terms of physical properties, this steel exhibits a tensile strength range of 115-234σb/MPa, a yield strength of 2σ 0.2 ≥/MPa, and an elongation capacity of 65 δ5≥ (%). It also has a HBS range of 123-321 and a HRC rating of 30.
This alloy steel is frequently utilized in low to moderately stressed components for machines, engines, and vehicles.
