Spiral Cutterhead for Delta Shopmaster TP400LS 12.5" Planer (Model 1342211)
Includes Full Set of Carbide Inserts – Ready to Install
Upgrade your Delta Shopmaster TP400LS 12.5" planer with our precision-engineered spiral cutterhead and experience a dramatic improvement in cut quality, noise reduction, and overall performance.
More and more woodworkers are retrofitting their planers and jointers with spiral cutterheads—and for good reason.
Why Upgrade to a Spiral Cutterhead?
✔ Smoother Finish – Virtually No Tear-Out
Each carbide insert is set at a slight shear angle, producing a true shearing cut. The helical, staggered cutting pattern delivers far superior results compared to traditional straight knives. The combined shear and staggered action significantly reduces tear-out and leaves a smooth, glossy finish—even on highly figured hardwood.
✔ Significantly Reduced Noise
Only a few inserts engage the wood at any given time, resulting in a quieter and smoother cutting experience compared to straight knife cutterheads.
✔ 10x Longer Cutting Life
Equipped with 15×15×2.5mm solid tungsten carbide inserts, which are much harder and more durable than high-speed steel. Each insert features four cutting edges—simply rotate 90° to access a fresh edge.
✔ Quick and Easy Maintenance
Precision-ground inserts (±0.0004" / ±0.01mm tolerance) are fully interchangeable. No knife setting or alignment required. Just loosen the screw, rotate or replace the insert, and retighten—back to work in minutes.
✔ Improved Dust Collection
Produces smaller, thinner chips that are easier to extract, helping improve dust collection efficiency.
✔ Lower Operating Cost
No sharpening required. Reduced sanding time thanks to superior surface finish. Long insert life and easy rotation mean this upgrade quickly pays for itself.
Kit Includes:
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High-tensile strength alloy steel cutter block
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Full set of carbide inserts pre-installed on 4 helical rows
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5 extra carbide inserts (FREE)
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5 extra insert screws (FREE)
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One pair of premium bearings (pre-installed)
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1 wrench
Built for durability, precision, and professional results—this spiral cutterhead is the perfect performance upgrade for your Delta Shopmaster TP400LS planer.
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
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.
