CNC切削速度 & フィード電卓

カーバイドエンドミルのCNC速度とフィードを計算する方法

正確な速度とフィードの計算は、収益性の高いCNC加工の基礎です。カーバイドツーリングの場合、パラメーターを正しく取得することは、競争力のある操作と絶え間ないツールの故障の違いを意味します。このガイドは、機械工と製造エンジニアに、一般的なワークピース材料全体でカーバイドエンドミルの切断パラメーターを最適化するために必要な式、データ、および戦略を提供します。

基本的な式

Spindle 切削速度 (RPM) is calculated from the desired surface speed:
Imperial: RPM = (SFM × 12) ÷ (π × D)
Metric: RPM = (Vc × 1000) ÷ (π × D)

送り Rate determines how fast the tool moves through material:
送り Rate = RPM × N × IPT where N = number of flutes and IPT = inches per tooth (chip load).

材料固有の推奨事項

Aluminum 6061: SFM 800-1,500. Use polished flute geometries and 2-3 flute designs. High RPM with moderate chip loads maximizes material removal without built-up edge.

Stainless Steel 304/316: SFM 250-500. Use 4-6 flute variable helix geometries to reduce chatter. Maintain minimum chip thickness to avoid work-hardening — the most common cause of edge chipping in stainless steel.

Titanium Grade 5: SFM 150-300. Low thermal conductivity concentrates heat at the cutting edge. Climb milling and through-spindle coolant are essential for tool life.

Hardened Steel (45-55 HRC): SFM 150-250. Use 6+ flute end mills with AlTiN or AlCrN coatings. Trochoidal milling with light radial engagement (5-15%) maximizes material removal while protecting the tool.

よくある質問

How do I calculate speed and feed for a carbide end mill? Use the calculator above. Select your material, tool diameter, flute count, and operation type. The calculator applies the standard formulas automatically.

What happens if the feed rate is too high? Tool deflection, poor surface finish, accelerated wear, and potential tool breakage. Reduce feed by 20-30% if you observe these symptoms.

How does cutting speed affect tool life? Per the Taylor equation, doubling cutting speed typically reduces tool life by 50-80%. Optimal speed balances productivity and tool cost.

Why is my carbide tool chipping in stainless steel? Most common cause is insufficient chip load — the tool rubs instead of cutting, causing work-hardening. Ensure minimum chip thickness is maintained.

What is the difference between SFM and RPM? SFM (Surface Feet per Minute) is the speed at which the cutting edge travels through material. RPM is the spindle speed calculated from SFM and tool diameter.

Why carbide over HSS? Carbide offers 3-5× higher cutting speeds, maintains hardness at high temperatures (800-1000°C), and enables machining of hardened materials up to 65 HRC.