When it comes to CNC processing steel parts, Die eat knives (also known as cut-off volume) is one of the most critical parameters you’ll need to master. It directly influences how fast you can machine parts, the quality of the final workpiece, and how long your tools last. For manufacturers in industries like automotive, machinery, and construction—where steel parts are everywhere—getting the eat knives right can mean the difference between meeting deadlines and facing costly delays, or producing durable parts vs. faulty ones. This guide breaks down everything you need to know about eat knives for CNC processing steel parts, from basic definitions to real-world application examples.
1. What Is “Eat Knives” in CNC Processing Steel Parts?
Erste, Lassen Sie uns klarstellen, was eat knives means in the context of CNC processing steel parts. It’s not a complex concept, but understanding it correctly is key to making smart decisions.
Definition of Eat Knives
Eat knives refers to the depth or width of material that a CNC tool cuts into the steel workpiece during machining. It has two main components:
- Axial depth of cut (ap): The distance the tool cuts into the workpiece along the tool’s axis (think of it as “how deep” the tool goes into the steel).
- Radial depth of cut (ae): The distance the tool cuts into the workpiece perpendicular to the tool’s axis (this is “how wide” the tool’s cut is across the steel surface).
Why Eat Knives Matters
Choosing the right eat knives isn’t just about cutting material—it’s about balancing three critical factors:
- Machining efficiency: Ein größeres eat knives removes more material at once, speeding up the process (great for roughing stages).
- Workpiece quality: Zu viel eat knives can cause tool vibration, leading to rough surfaces or even dimensional errors in the steel part.
- Tool life: Excessive eat knives puts extra stress on the tool, causing it to break or wear out quickly—costing you money in tool replacements.
Zum Beispiel, if you set the eat knives too high when machining a steel gear, the tool might vibrate, leaving uneven teeth on the gear. This gear would then fail to mesh properly with other components, leading to product defects.
2. Key Factors Influencing Eat Knives for CNC Processing Steel Parts
The ideal eat knives for your steel part isn’t a one-size-fits-all number—it depends on four main factors. Ignoring any of these can lead to poor results.
2.1 Steel Material Hardness
The harder the steel, the smaller the eat knives you should use. Hard steel resists cutting more, so a large eat knives would create excessive cutting force, damaging the tool or the workpiece.
Steel Type | Härte (HRC) | Recommended Max Axial Eat Knives (ap) |
45# Stahl (medium carbon) | 18 - 22 | 1.0 mm |
Edelstahl 304 | 15 - 18 | 0.8 mm |
Hochgeschwindigkeitsstahl (HSS) | 60 - 65 | 0.3 mm |
Beispiel: Bearbeitung 45# Stahl (HRC 20) with a 1.0mm eat knives works well, but if you try the same eat knives on high-speed steel (HRC 62), the tool will likely chip within 10 minutes of machining.
2.2 Tool Material and Shape
Not all CNC tools are built the same—their material and shape determine how much eat knives they can handle.
- Tool Material:
- Carbide tools: Durable and heat-resistant, so they can handle larger eat knives (up to 1.0mm for 45# Stahl).
- Ceramic tools: Even harder than carbide, ideal for high-hardness steel (Z.B., HSS) with small to medium eat knives (0.3 – 0.6mm).
- Hochgeschwindigkeitsstahl (HSS) Werkzeuge: Softer than carbide or ceramic, limited to small eat knives (0.2 – 0.5mm for 45# Stahl).
- Tool Shape:
- Round nose knives: Their curved tip distributes cutting force evenly, allowing slightly larger eat knives than flat-end knives.
- Flat-end knives: Better for precise, shallow cuts (smaller eat knives) because their sharp edge can easily chip if force is too high.
2.3 CNC Machine Performance
Your machine’s power, Steifheit, and accuracy play a big role in eat knives selection. A weak or wobbly machine can’t handle large eat knives—it will vibrate, ruining the part.
- Machine Power: Machines with higher spindle power (Z.B., 15kW) can handle larger eat knives than low-power machines (Z.B., 5kW). A 15kW machine can cut 45# steel with a 1.0mm eat knives, while a 5kW machine may struggle with 0.6mm.
- Machine Rigidity: Loose spindle bearings or unstable worktables cause vibration. A rigid machine (with heavy-duty frames) can maintain accuracy even with larger eat knives.
- Machine Accuracy: Modern machines with high-precision linear guides can handle smaller, genauer eat knives (Z.B., 0.1mm for finishing), which old or poorly maintained machines can’t.
2.4 Processing Stage (Rauen vs. Fertig)
The stage of machining—whether you’re roughing (removing excess material) or finishing (refining the part)—dictates the eat knives Größe. This is one of the most important factors to consider.
3. Eat Knives Selection Principles for Different Processing Stages
The goal of each processing stage is different, so your eat knives should align with that goal. Below are the principles for roughing, semi-finishing, and finishing.
3.1 Roughing Stage: Prioritize Efficiency
Roughing’s job is to quickly remove most of the excess material from the steel workpiece. Here, you want a large eat knives to save time—but not so large that you damage the tool or leave no room for finishing.
- Key Principle: Use the largest eat knives your tool and machine can handle, while leaving a machining allowance (extra material) for semi-finishing and finishing.
- Typical Allowance: 0.3 – 0.5mm on all sides of the workpiece.
Real-World Roughing Case:
When roughing 45# Stahl (a common medium-carbon steel) for a machine bracket:
- Werkzeug: Φ20mm carbide disc cutter
- Axial eat knives (ap): 0.5 – 1.0mm
- Spindle speed (S): 1200 - 1500 Drehzahl
- Futterrate (F): 1000 - 1500 mm/min
- Ergebnis: The bracket’s excess material (5mm total) is removed in just 2 passes, and a 0.3mm allowance is left for semi-finishing.
3.2 Semi-Finishing Stage: Balance Efficiency and Quality
Semi-finishing smooths out the rough surface left by roughing and prepares the workpiece for final finishing. Der eat knives here is smaller than roughing but larger than finishing.
- Key Principle: Reduce eat knives to improve surface quality, while still removing most of the remaining allowance.
Real-World Semi-Finishing Case:
Semi-finishing the same 45# steel machine bracket:
- Werkzeug: Φ20mm carbide disc sleeve cutter
- Axial eat knives (ap): 0.3 – 0.5mm
- Spindle speed (S): 1500 - 1800 Drehzahl (faster than roughing for smoother cuts)
- Futterrate (F): 800 - 1200 mm/min (slower than roughing to reduce vibration)
- Ergebnis: The bracket’s surface becomes smoother, and only 0.1mm allowance is left for finishing.
3.3 Finishing Stage: Prioritize Quality
Finishing’s goal is to achieve the part’s final dimensions and surface quality. Here, eat knives is the smallest—focused on precision, not speed.
- Key Principle: Use a small eat knives to minimize tool vibration and ensure dimensional accuracy.
Real-World Finishing Case:
Finishing the 45# steel machine bracket (final requirement: glatte Oberfläche, ±0.01mm dimensional accuracy):
- Werkzeug: Φ20mm carbide disc sleeve cutter (sharpened for precision)
- Axial eat knives (ap): 0.1 – 0.2mm
- Spindle speed (S): 2000 - 2500 Drehzahl (fastest speed for clean cuts)
- Futterrate (F): 500 - 800 mm/min (slowest feed to avoid surface marks)
- Ergebnis: The bracket meets all dimensional and surface quality standards, with no visible tool marks.
4. Practical Tips to Avoid Common Eat Knives Mistakes
Even with the right principles, mistakes can happen. Here are three tips to keep your eat knives on track:
- Test with Small Batches First: Before machining a large order, test your eat knives on 1–2 sample parts. Zum Beispiel, if you’re unsure about using a 0.8mm eat knives für Edelstahl, try 0.6mm first—if the tool lasts and the part quality is good, you can increase it slightly.
- Monitor Tool Wear: A worn tool can’t handle the same eat knives as a new one. Check your tool every 30 minutes during machining—if you see chips or dull edges, reduce the eat knives or replace the tool.
- Adjust for Machine Vibration: If your machine starts vibrating during machining, it’s a sign the eat knives is too large. Reduce the eat knives by 0.2mm and test again—vibration should stop, and surface quality will improve.
Yigu Technology’s View on Eat Knives for CNC Processing Steel Parts
Bei Yigu Technology, Wir wissen eat knives for CNC processing steel parts is the backbone of efficient, high-quality manufacturing. Über 10 Jahre, Wir haben geholfen 300+ clients—from auto parts makers to machinery manufacturers—optimize their eat knives Parameter. We start by analyzing the steel’s hardness and tool material, then tailor eat knives to each processing stage (Z.B., 1.0mm for 45# steel roughing, 0.1mm for finishing). Our team also provides on-site testing to ensure parameters work with clients’ machines, cutting tool replacement costs by 25% and improving production efficiency by 30%. Für uns, getting eat knives right isn’t just about numbers—it’s about solving clients’ real-world challenges.
FAQ
Q1: Can I use the same eat knives for different types of steel?
A: NEIN. Harder steel (Z.B., high-speed steel) needs smaller eat knives than softer steel (Z.B., 45# Stahl). Using the same eat knives for both will either damage the tool (on hard steel) or waste time (on soft steel, where you could use a larger eat knives).
Q2: What happens if I set the eat knives too small?
A: A too-small eat knives won’t damage tools or parts, but it will slow down machining. Zum Beispiel, Rauen 45# steel with a 0.2mm eat knives instead of 1.0mm would take 5x longer to remove the same amount of material—missing production deadlines.
Q3: Do I need to adjust eat knives if I switch from a carbide tool to an HSS tool?
A: Ja. HSS tools are softer than carbide, so you’ll need to reduce the eat knives by 40–50%. Zum Beispiel, if you used 1.0mm eat knives with a carbide tool on 45# Stahl, switch to 0.4–0.5mm with an HSS tool to avoid tool wear.