Shenzhen machine shop several thread processing methods procurement engineers must know!

Thread Processing Is One Of The Most Important Applications Of CNC Machining Centers . The Processing Quality Efficiency Of Threads In Shenzhen Machining Plants Will Directly Affect The Processing Quality Of Parts The Production Efficiency Of Machining Centers .

With The Improvement Of CNC Machining Center Performance Cutting Tool Improvement, Thread Machining Methods Are Also Constantly Improving, Thread Machining Accuracy Efficiency Are Gradually Improving. In Order To Enable Process Personnel To Reasonably Thread Machining Methods In Machining, Improve Production Efficiency, Avoid Quality Accidents, Several Thread Machining Methods Commonly Used In CNC Machining Centers Are Summarized As Follows: Huiwen Zhizao Is A Machining Factory With More Than Ten Years Of CNC Machining Experience , With Complete Equipment, CNC Lathe/Milling/Grinding/Drilling/Machining. Partners With Parts Processing Needs Are Welcome To Call Us For Quotation.

1. Tap Processing Method

1.1 Classification Characteristics Of Tap Processing

Using A Tap To Process Threaded Holes Is The Most Commonly Used Processing Method. It Is Mainly Suitable For Threaded Holes With Small Diameters (D<30) Low Requirements For Hole Position Accuracy.

In The 1980s, Threaded Holes Were All Tapped Using A Flexible Tapping Method, That Is, A Flexible Tapping Chuck Was Used To Hold The Tap. The Tapping Chuck Could Be Used For Axial Compensation To Compensate For The Feed Error Caused By The Asynchronous Axial Feed Of The Machine Tool The Spindle Speed, Ensuring The Correct Pitch. The Flexible Tapping Chuck Has A Complex Structure, High Cost, Easy Damage, Low Processing Efficiency. In Recent Years, The Performance Of CNC Machining Centers Has Gradually Improved, The Rigid Tapping Function Has Become A Basic Configuration Of CNC Machining Centers.

Therefore, Rigid Tapping Has Become The Main Method Of Thread Processing In Shenzhen Machining Plants .

That Is, The Tap Is Clamped By A Rigid Spring Chuck, The Spindle Feed Spindle Speed Are Kept Consistent By The Machine Tool Control.

Compared With Flexible Tapping Chucks, Spring Chucks Have Simple Structure, Low Price Wide Application. In Addition To Clamping Taps, They Can Also Clamp End Mills, Drills Other Tools, Which Can Reduce Tool Costs. At The Same Time, Rigid Tapping Can Be Used For High-Speed Cutting, Improve The Efficiency Of Machining Centers Reduce Manufacturing Costs.

1.2 Determination Of Thread Bottom Hole Before Tapping

The Processing Of The Thread Bottom Hole Has A Great Impact On The Life Of The Tap, The Quality Of Thread Processing, Etc. Usually, The Diameter Of The Thread Bottom Hole Drill Bit Is Selected To Be Close To The Upper Limit Of The Thread Bottom Hole Diameter Tolerance. For Example, The Bottom Hole Diameter Of The M8 Threaded Hole Is Ф6.7+0.27mm, The Drill Bit Diameter Is Selected To Be Ф6.9mm. In This Way, The Processing Allowance Of The Tap Can Be Reduced, The Load Of The Tap Can Be Reduced, The Service Life Of The Tap Can Be Increased.

1.3 Selection Of Taps

When Choosing A Tap, First Of All, You Must Choose The Corresponding Tap According To The Material Being Processed. Tool Companies Produce Different Types Of Taps According To Different Processing Materials, So You Must Pay Special Attention When Choosing.

Because Taps Are Very Sensitive To The Material Being Processed Compared To Milling Cutters Boring Cutters. For Example, Using A Tap For Processing Cast Iron To Process Aluminum Parts Can Easily Cause Thread Loss, Tangled Threads, Even Tap Breakage, Resulting In The Scrapping Of The Workpiece. Secondly, Attention Should Be Paid To The Difference Between Through-Hole Taps Blind-Hole Taps. Through-Hole Taps Have A Longer Front Guide Use Front Chip Removal. Blind-Hole Taps Have A Shorter Front Guide Use Rear Chip Removal. Huiwen Zhizao Is A Machining Factory With More Than Ten Years Of CNC Machining Experience. It Has A Full Range Of Equipment, Including CNC Turning/Milling/Grinding/Drilling/Machining. Partners With Parts Processing Needs Are Welcome To Call Us For Quotes.

Using A Through-Hole Tap To Process A Blind Hole Cannot Guarantee The Thread Processing Depth. Furthermore, If A Flexible Tapping Chuck Is Used, The Shank Diameter The Width Of The Square Should Be The Same As Those Of The Tapping Chuck; The Shank Diameter Of The Rigid Tapping Tap Should Be The Same As The Spring Collet Diameter. In Short, Only By Choosing A Reasonable Tap Can The Smooth Processing Be Guaranteed.

1.4 NC Programming For Tap Machining

The Programming Of Tapping Is Relatively Simple. At Present, The Machining Centers Of Shenzhen Machining Factories Generally Have Solidified Tapping Subroutines, Only Need To Assign Values To Various Parameters. However, It Should Be Noted That Different CNC Systems Have Different Subroutine Formats, The Meanings Of Some Parameters Are Different.

For Example, The Programming Format Of SIEMEN840C Control System Is: G84 X_Y_R2_ R3_R4_R5_R6_R7_R8_R9_R10_R13_. When Programming, You Only Need To Assign Values To These 12 Parameters.

2. Thread Milling Method

2.1 Characteristics Of Thread Milling

Thread Milling Is A Milling Method That Uses Thread Milling Tools Three-Axis Linkage Of The Machining Center, Namely, Circular Interpolation Of The X Y Axes Linear Feed Of The Z Axis To Process Threads.

Thread Milling Is Mainly Used For Processing Large-Hole Threads Threaded Holes Of Difficult-To-Process Materials. It Has The Following Main Features:

⑴ Shenzhen Machining Factory Has Fast Processing Speed, High Efficiency High Processing Precision. The Tool Material Is Generally Cemented Carbide Material, The Cutting Speed Is Fast. The Manufacturing Precision Of The Tool Is High, So The Milling Thread Precision Is High.

⑵ The Milling Tool Has A Wide Range Of Applications. As Long As The Pitch Is The Same, Whether It Is Left-Handed Right-Handed, The Same Tool Can Be Used, Which Is Conducive To Reducing Tool Costs.

⑶ Milling Is Easy To Remove Chips Cool, Has Better Cutting Conditions Than Taps. It Is Particularly Suitable For Thread Processing Of Difficult-To-Process Materials Such As Aluminum, Copper, Stainless Steel, Especially For Thread Processing Of Large Parts Parts Made Of Precious Materials. It Can Ensure The Quality Of Thread Processing The Safety Of Workpieces.

(4) Because There Is No Front-End Guide Of The Tool, It Is Suitable For Processing Blind Holes With Shorter Thread Bottom Holes Holes Without Back-Cut Grooves.

2.2 Classification Of Thread Milling Tools In Shenzhen Machining Plants

There Are Two Types Of Thread Milling Cutters: One Is A Machine-Clamped Carbide Insert Milling Cutter, The Other Is An Integral Carbide Milling Cutter. Machine-Clamped Cutters Have A Wide Range Of Applications, Can Process Holes With A Thread Depth Less Than The Blade Length, As Well As Holes With A Thread Depth Greater Than The Blade Length. Integral Carbide Milling Cutters Are Generally Used To Process Holes With A Thread Depth Less Than The Tool Length.

2.3 CNC Programming Of Thread Milling In Shenzhen Machining Plant

The Programming Of Thread Milling Tools Is Different That Of Other Tools. If The Processing Program Is Compiled Incorrectly, It Is Easy To Cause Tool Damage Thread Processing Errors. The Following Points Should Be Noted When Compiling:

⑴ First, The Thread Bottom Hole Should Be Processed Well. Small Diameter Holes Should Be Processed With A Drill, Larger Holes Should Be Processed By Boring To Ensure The Accuracy Of The Thread Bottom Hole. Huiwen Zhizao Is A Machining Factory With More Than Ten Years Of CNC Processing Experience. It Has A Full Range Of Equipment, CNC Lathe/Milling/Grinding/Drilling/Processing. Partners With Parts Processing Needs Are Welcome To Call Us For Quotation.

⑵ The Tool Should Use An Arc Trajectory When Cutting In Out, Usually 1/2 Circle For Cutting In Out, The Z Axis Direction Should Move 1/2 Pitch To Ensure The Thread Shape. The Tool Radius Compensation Value Should Be Brought In At This Time.

⑶ After One Circle Of Circular Interpolation Between X Y Axes, The Spindle Should Move One Pitch Along The Z Axis Direction, Otherwise, The Thread Will Be Screwed Randomly.

⑷ Specific Example Program: The Thread Milling Cutter Diameter Is Φ16, The Threaded Hole Is M48×1.5, The Threaded Hole Depth Is 14.

The Processing Procedures Are As Follows:

　　(The Thread Bottom Hole Procedure Is Omitted, This Hole Should Be Bored To Bottom)

　　G0 G90 G54 X0 Y0

　　G0 Z10 M3 S1400 M8

　　G0 Z-14.75 Feed To The Deepest Point Of The Thread

　　G01 G41 X-16 Y0 F2000 Move To The Feed Position Add Radius Compensation

　　G03 X24 Y0 Z-14 I20 J0 F500 Cut In With 1/2 Circle Arc

　　G03 X24 Y0 Z0 I-24 J0 F400 Cutting The Entire Thread

　　G03 X-16 Y0 Z0.75 I-20 J0 F500 Cut Out Using 1/2 Circle Arc G01 G40 X0 Y0 Return To The Center Cancel Radius Compensation

　　G0 Z100

　　M30

3. Pick--Hook Method

3.1 Characteristics Of The Pick--Button Method

Large Threaded Holes Are Sometimes Found On Box-Type Parts. In The Absence Of Taps Thread Milling Cutters, A Method Similar To Lathe Threading Can Be Used.

Install The Thread Turning Tool On The Boring Bar To Bore The Thread.

Shenzhen Machining Factory Company Once Processed A Batch Of Parts, The Thread Was M52x1.5, The Positioning Accuracy Was 0.1mm. Due To The High Positioning Accuracy Requirements Large Threaded Holes, Taps Could Be Used For Processing, There Were No Thread Milling Cutters. After Testing, The Pick--Thread Method Was Used To Ensure The Processing Requirements.

3.2 Precautions For The Pick--Button Method

⑴ After The Spindle Is Started, There Should Be A Delay Time To Ensure That The Spindle Reaches The Rated Speed.

⑵ When Retracting The Tool, If It Is A Hand-Ground Thread Tool, Since The Tool Cannot Be Ground Symmetrically, Reverse Retraction Cannot Be Used. The Spindle Must Be Oriented, The Tool Must Move Radially, Then Retract The Tool.

⑶ The Manufacture Of The Tool Bar Must Be Accurate, Especially The Position Of The Tool Groove Must Be Consistent. If It Is Inconsistent, Multiple Tool Bars Cannot Be Used For Processing. Otherwise, It Will Cause Random Buckling.

⑷ Even If It Is A Very Thin Buckle, It Cannot Be Picked Out In One Go, Otherwise It Will Cause The Teeth To Fall Off The Surface Roughness Will Be Poor. It Should Be Picked Out In At Least Two Cuts.

⑸ The Processing Efficiency Is Low It Is Only Suitable For Single-Piece Small Batches, Special Pitch Threads Situations There Are No Corresponding Tools.

3.3 Specific Example Program

　　N5 G90 G54 G0 X0 Y0

　　N10 Z15

　　N15 S100 M3 M8

　　N20 G04 X5 Delay To Allow The Spindle To Reach Rated Speed

　　N25 G33 Z-50 K1.5 Buckle

　　N30 M19 Spindle Orientation

　　N35 G0 X-2 Let Go

　　N40 G0 Z15 Retract