Hi everyone! Today, I’m going to talk about stainless steel CNC machining～ Many newbies often encounter various problems when they first start, such as rapid tool wear, poor surface quality, or difficulty in chip disposal. Don’t worry! Combining my own experience, I’ll explain how to select tools and set parameters, hoping to help you out! 😊  

 1. Why is Stainless Steel Machining So Challenging?  

Stainless steel itself has high hardness, great toughness, and is prone to work hardening, so it has extremely high requirements for tools and parameters. In my opinion, if you don’t choose the right tools, it will really be a waste of both time and money! Moreover, its thermal conductivity is poor, so cutting heat tends to concentrate at the tool tip—if you’re not careful, the tool will be "burnt out"... 🔥  

 2. Tool Selection Guide: Stop Misusing Tools!  

Tool selection is truly a profound knowledge! For stainless steel machining, coated cemented carbide tools are the best choice, such as YG series (tungsten-cobalt type). They have good toughness, high-temperature resistance, and can reduce tool adhesion. The end mill with TiAlN coating I usually use works really well! 💪  

During rough machining, it is recommended to use inserts with a large rake angle (15°~20°) and strong chip breakers to ensure smooth chip evacuation; for finish machining, you need to select tools with sharp cutting edges to guarantee surface finish.  

⚠️ Note: Never use YT series (tungsten-cobalt-titanium) tools, especially when machining austenitic stainless steels like 304 and 316. These tools tend to have material affinity with the workpiece, leading to rapid wear!  

 3. Cutting Parameter Setting: Remember These Values to Double Efficiency!  

No matter how good the tool is, it’s useless if the parameters are set incorrectly! I’ve sorted out a general reference table, and newbies can directly apply it to try～ 👇  

| Material Type       | Cutting Speed (Vc) | Feed Rate (f)     | Cutting Depth (ap) |  

|---------------------|--------------------|--------------------|---------------------|  

| 304 Stainless Steel | 70-120 m/min       | 0.15-0.35 mm/r     | 1.0-5.0 mm          |  

| 316 Stainless Steel | 60-100 m/min       | 0.12-0.30 mm/r     | 1.0-4.0 mm          |  

| 17-4PH Hardened Steel | 50-100 m/min     | 0.10-0.25 mm/r     | 0.5-3.0 mm          |  

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🔹 Core Tips:  

- During roughing, use lower spindle speed and larger feed rate to quickly remove material;  

- During finishing, increase spindle speed and reduce feed rate to improve surface quality;  

- Remember to use cutting fluid! High-pressure internal cooling is recommended, as it can cool the tool and help break chips.  

 4. FAQ: Let Me Offer Solutions!  

❓ Q: What should I do if there’s always tool vibration during machining?  

A: It may be due to insufficient rigidity! Try reducing the spindle speed, shortening the tool holder overhang, or replacing it with an anti-vibration tool holder.  

❓ Q: Chips won’t break and get tangled everywhere?  

A: Increasing the feed rate is the most effective method! Also, check if the chip breaker matches the machining condition, or use high-pressure cooling to flush away chips.  

❓ Q: The surface quality always fails to meet requirements?  

A: During finishing, increase the spindle speed, reduce the feed rate, and ensure the tool is sharp～ If that still doesn’t work, try using the wiper edge technology.  

 5. Personal Insights: Avoid These Pitfalls!  

Let me add a few more words～ Never rush when machining stainless steel! ⚠️ Low-speed and high-feed machining is often more stable than high-speed and light-cutting, especially for new machines. Additionally, it’s important to regularly check tool wear—don’t wait until the tool edge collapses to replace it, as the loss will outweigh the gain!  

By the way, if you’re doing mass production, I strongly recommend investing in coated tools and high-pressure cooling systems. In the long run, they can save a lot of costs and time～ 👍  

In short, stainless steel CNC machining requires more practice and parameter adjustment. Once you get familiar with it, you’ll find it’s not that difficult after all! I hope my sharing can help you. If you have other questions, feel free to leave a message and discuss together! ✨