cnc machining turning/milling/planing/grinding/drilling/boring, how exactly?

Dealing With CNC Machining Every Day , I Believe You Must Have A Deep Impression Of Machining Accuracy, But How Much Do You Know About "Tolerance Grade"? Tolerance Grade Refers To The Grade That Determines The Degree Of Dimensional Accuracy. The National Standard Stipulates That It Is Divided Into 20 Grades, IT01, IT0, IT1, IT2 To IT18. The Larger The Number, The Lower The Tolerance Grade (Machining Accuracy), The Larger The Allowable Range Of Dimensional Variation (Tolerance Value), The Lower The Machining Difficulty.

Product Parts Need To Achieve Different Processing Accuracy According To Their Functions, The Selected Processing Methods Processing Technologies Are Also Different. This Article Introduces The Processing Accuracy That Can Be Achieved By Several Common Processing Methods Such As Turning, Milling, Planing, Grinding, Drilling, Boring. Huiwen Zhizao Is A Machining Factory With More Than Ten Years Of CNC Processing Experience . It Has A Full Range Of Equipment CNC Turning/Milling/Grinding/Drilling/Processing. Partners With Parts Processing Needs Are Welcome To Call Us For Quotes.

IT Standard Tolerance Grade Table

(Click On The Image To Enlarge It)

Note: When The Basic Size Is Less Than 1mm, There Is No IT14 To IT18

01 Turning

The Workpiece Rotates The Turning Tool Moves In A Straight Line Curve In The Plane For Cutting. Turning Is Generally Performed On A Lathe To Process The Inner Outer Cylindrical Surfaces, End Faces, Conical Surfaces, Forming Surfaces Threads Of The Workpiece.

The Turning Accuracy Is Generally IT8~IT7, The Surface Roughness Is 1.6~0.8μm. The Shenzhen Huiwen Intelligent Manufacturing Technology Co., Ltd. Team Was Established In 2010 Is Located On The 1st Floor Of Building F3, Tianyou Maker Industrial Park, Lixinhu, Fuyong, Bao'an District, Shenzhen. It Has Long Been Committed To The Processing Of High-Precision, High-Difficulty, Easy-To-Deform Metal Plastic Parts , Small Medium-Volume Production Manufacturing Of Light Alloy Composite Materials (Such As Aluminum Alloy, Carbon Fiber, Etc.),  Robot Parts Procurement Customization Services.

1) Rough Turning Strives To Improve Turning Efficiency By Using Large Cutting Depth Large Feed Rate Without Reducing Cutting Speed, But The Machining Accuracy Can Only Reach IT11, The Surface Roughness Is Rα20~10μm.

2) For Semi-Finishing Finishing Turning, High Speed Small Feed Rate Cutting Depth Should Be Used As Much As Possible. The Machining Accuracy Can Reach IT10~IT7, The Surface Roughness Is Rα10~0.16μm.

3) Using A Finely Polished Diamond Turning Tool On A High-Precision Lathe To High-Speed Precision Turn Non-Ferrous Metal Parts Can Achieve A Machining Accuracy Of IT7~IT5 A Surface Roughness Of Rα0.04~0.01μm. This Type Of Turning Is Called "Mirror Turning".

02 Milling

Milling Is A Highly Efficient Machining Method That Uses A Rotating Multi-Edged Tool To Cut Workpieces. It Is Suitable For Machining Planes, Grooves, Various Forming Surfaces (Such As Splines, Gears Threads) Special Surfaces Of Molds. According To Whether The Main Motion Speed Direction During Milling Is The Same Opposite To The Workpiece Feed Direction, It Is Divided Into Forward Milling Reverse Milling.

The Milling Processing Accuracy Can Generally Reach IT8~IT7, The Surface Roughness Is 6.3~1.6μm.

1) The Machining Accuracy During Rough Milling Is IT11~IT13, The Surface Roughness Is 5~20μm.

2) The Machining Accuracy During Semi-Finishing Milling Is IT8~IT11, The Surface Roughness Is 2.5~10μm.

3) The Machining Accuracy During Fine Milling Is IT16~IT8, The Surface Roughness Is 0.63~5μm.

03 Planing

Planing Is A Cutting Method That Uses A Planer To Make Horizontal Relative Linear Reciprocating Motion On The Workpiece, Is Mainly Used For The Shape Processing Of Parts.

The Planing Processing Accuracy Can Generally Reach IT9~IT7, The Surface Roughness Is Ra6.3~1.6μm.

1) The Rough Planing Accuracy Can Reach IT12~IT11, The Surface Roughness Is 25~12.5μm.

2) The Semi-Precision Planing Accuracy Can Reach IT10~IT9, The Surface Roughness Is 6.2~3.2μm.

3) The Precision Of Fine Planing Can Reach IT8~IT7, The Surface Roughness Is 3.2~1.6μm.

04 Grinding

Grinding Refers To A Processing Method That Uses Abrasives Grinding Tools To Remove Excess Material A Workpiece. It Is A Finishing Method Widely Used In The Machinery Manufacturing Industry.

Grinding Is Usually Used For Semi-Finishing Finishing, With An Accuracy Of IT8~IT5 Even Higher, The Surface Roughness Is Generally Ground To 1.25~0.16μm.

1) The Surface Roughness Of Precision Grinding Is 0.16~0.04μm.

2) The Surface Roughness Of Ultra-Precision Grinding Is 0.04~0.01μm.

3) The Surface Roughness Of Mirror Grinding Can Reach Below 0.01μm.

05 Drilling

Drilling Is A Basic Method Of Hole Processing. Drilling Is Often Performed On Drilling Machines Lathes, But Can Also Be Performed On Boring Machines Milling Machines.

The Machining Accuracy Of Drilling Is Low, Generally Only Reaching IT10, The Surface Roughness Is Generally 12.5~6.3μm. After Drilling, Expansion Reaming Are Often Used For Semi-Finishing Finishing.

06 Boring

Boring Is A Cutting Process That Uses A Tool To Enlarge The Inner Diameter Of A Hole Other Circular Contour. Its Application Range Generally Ranges Semi-Roughing To Finishing. The Tool Used Is Usually A Single-Edged Boring Tool (Called A Boring Bar).

1) The Boring Accuracy Of Steel Materials Can Generally Reach IT9~IT7, The Surface Roughness Is 2.5~0.16μm.

2) The Machining Accuracy Of Precision Boring Can Reach IT7~IT6, The Surface Roughness Is 0.63~0.08μm.

The Following Table Is More Intuitive!

The Shenzhen Huiwen Intelligent Manufacturing Technology Co., Ltd. Team Was Established In 2010 Is Located On The 1st Floor Of Building F3, Tianyou Maker Industrial Park, Lixinhu, Fuyong, Bao'an District, Shenzhen. It Has Long Been Committed To The Processing Of High-Precision, High-Difficulty, Easy-To-Deform Metal Plastic Parts, Small Medium-Batch Production Of Lightweight Alloy Composite Materials (Such As Aluminum Alloy, Carbon Fiber, Etc.) Parts, Procurement Customization Of Robot Parts.