Mitsubishi SPMW120304 UTI20T | Carbide Milling Insert for Steel
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SPMW120304 UTI20T
Mitsubishi Materials | Uncoated Carbide for Extreme Edge Toughness
The Mitsubishi SPMW120304 UTI20T is a workhorse indexable carbide insert designed for general-purpose milling. Utilizing the legendary UTI20T grade, this insert is the go-to choice for workshops requiring a long-tail tool solution that balances cost-effectiveness with high fracture resistance. It is exceptionally stable for machining stainless steel, alloy steels, and gray cast iron in both manual and CNC operations.
ISO Code Breakdown
Square Shape
11° Relief Angle
M-Class Tolerance
With Fixing Hole
12.7mm IC Size
3.18mm Thick
0.4mm Radius
Global Standard Comparison
| Specification | Metric (ISO) | Inch (ANSI) Equivalent |
|---|---|---|
| Part Number | SPMW120304 | SPMW 421 |
| Inscribed Circle ($IC$) | 12.7 mm | 0.500" |
| Thickness ($S$) | 3.18 mm | 0.125" |
| Corner Radius ($RE$) | 0.4 mm | 0.016" |
Grade: UTI20T Tough Carbide
The UTI20T grade is an uncoated micro-grain carbide specifically designed for interrupted cutting and unstable machining conditions. While coated grades may peel under extreme pressure, the UTI20T maintains a consistent cutting edge. It is highly recommended for machining austenitic stainless steels and cast iron where thermal shock resistance is required.
Geometry: W-Type General Purpose
The W-Type geometry features a flat top face with a countersunk hole for secure clamping. It provides a sharp shearing action that reduces cutting torque and vibration. This makes it ideal for older machines or lighter CNC setups where spindle rigidity may be an issue.
Recommended Cutting Parameters
| Workpiece Material | Cutting Speed ($v_c$) | Feed per Tooth ($f_z$) |
|---|---|---|
| Mild Steel (1018/1045) | 100 - 180 m/min | 0.10 - 0.25 mm/t |
| Stainless Steel (304/316) | 60 - 120 m/min | 0.08 - 0.20 mm/t |
| Cast Iron (Gray/Ductile) | 80 - 160 m/min | 0.15 - 0.35 mm/t |
Universal Holder Compatibility
This insert fits all standard SPM 42x series tool holders and Mitsubishi screw-on milling cutters.
View Compatible Milling Holders →
Technical FAQ & Buying Guide
Absolutely. Our CNC carbide inserts (including CNMG, WNMG, DNMG, and APMT series) are manufactured strictly adhering to international ISO/ANSI specifications. A CNMG 120408 from OYYU BEYOND will flawlessly fit any standard turning tool holder or indexable tool from major global brands like Sandvik Coromant, Kennametal, Iscar, Walter, or SECO, providing a highly cost-effective premium alternative without sacrificing tolerance or tool life.
We offer optimized CVD and PVD multi-layer coatings for different ISO material groups:
- For Carbon/Alloy Steel (ISO P): Choose our thick multi-layer CVD coated grades (e.g., Al2O3 + TiN). They provide exceptional crater wear resistance and thermal barriers during high-speed dry or wet roughing.
- For Stainless Steel (ISO M): Choose our nano-structured PVD coated grades with sharp, positive chipbreakers (like -TM or -MA). This combination prevents work hardening and effectively controls sticky chips.
The optimal cutting parameters vary depending on the workpiece hardness and operation type:
- For General Steel Turnings: Recommended cutting speed ($V_c$) ranges from 150 to 280 m/min, with a feed rate ($f$) of 0.15 to 0.45 mm/rev.
- For Stainless Steel Finishing: Recommended cutting speed ($V_c$) is 120 to 200 m/min, with a feed rate ($f$) of 0.10 to 0.25 mm/rev.Always adjust parameters based on early wear patterns: increase $V_c$ if built-up edge occurs, or reduce $V_c$ if severe flank wear is observed.
Yes, we support machine shops, distributors, and global buyers with tiered wholesale pricing and competitive volume discounts. We also provide OEM custom manufacturing solutions for tool holders and carbide inserts based on your technical drawings. Contact our team to request a quick B2B quotation.
We provide secure worldwide express shipping (via DHL, FedEx, and UPS) with specialized, vibration-proof industrial packaging to ensure tools arrive in perfect condition. In-stock items are dispatched within 24-48 hours, while custom or bulk orders typically have a stable lead time of 15-25 days.
All our cutting tools and tool holders are manufactured strictly in accordance with ISO 9001 and international industrial standards. Every batch undergoes 100% rigorous quality control testing using high-precision optical measuring equipment to ensure reliable tool life and stable performance in continuous mass production.