Flat Bed CNC Lathe for Shaft, Disc and Flange Machining

Flat bed CNC lathes are widely used for machining **shafts, discs, flanges, sleeves, rollers and other rotational metal parts**.

The correct machine depends mainly on the workpiece diameter, length, weight, material and machining process. A Ø120 × 1000 mm shaft and a Ø500 × 80 mm flange may both be turned on a CNC lathe, but they require very different machine capacity, workholding and support.

This guide explains how to ｓｅｌｅｃｔ a flat bed CNC lathe for real industrial shaft, disc and flange machining applications.

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## 1. Industry

Flat bed CNC lathes are commonly used in general machinery, hydraulic equipment, automotive components, energy equipment, valve manufacturing and heavy machinery.

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

The main advantage of a flat bed CNC lathe is its combination of **turning length, rigidity, workpiece support and CNC productivity**.

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# 2. Workpiece

## Shaft Machining

Shafts usually have a relatively small diameter compared with their length.

Typical operations include:

1. OD turning

2. Facing

3. Step turning

4. Grooving

5. External threading

6. Taper turning

7. Drilling and boring

### Example: 40Cr Stepped Shaft

| Item | Data |

|---|---:|

| Workpiece | Transmission shaft |

| Material | 40Cr |

| Maximum OD | Ø120 mm |

| Length | 1000 mm |

| Process | OD turning + facing + grooving + M60 thread |

| Production | 30 pcs/month |

| Workholding | Chuck + tailstock |

For this workpiece, diameter is not the main difficulty. **Workpiece length and support** are more important.

A buyer searching:

**“What CNC lathe do I need for a 1-meter-long 120 mm steel shaft?”**

should check the maximum workpiece length, maximum turning length, tailstock configuration and whether a steady rest is required.

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## Disc Machining

Discs are normally **shorter but larger in diameter** than shafts.

Typical parts include:

- Brake discs

- Couplings

- Gear blanks

- End covers

- Large washers

- Circular plates

### Example: 45# Steel Disc

| Item | Data |

|---|---:|

| Material | 45# Steel |

| Outside diameter | Ø380 mm |

| Thickness | 65 mm |

| Center bore | Ø120 mm |

| Process | Facing + OD turning + ID boring |

| Batch | 100 pcs/month |

For disc machining, the most important specifications are usually:

**swing over bed + swing over carriage + chuck size + spindle speed + turret configuration**

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## Flange Machining

Flanges require similar capacity to discs but usually involve more ID boring, facing and groove operations.

### Example: 316 Stainless Steel Flange

| Item | Data |

|---|---:|

| Material | 316 Stainless Steel |

| Outside diameter | Ø450 mm |

| Thickness | 80 mm |

| Bore | Ø220 mm |

| Process | Facing + OD turning + ID boring + groove |

| Required surface finish | Ra 1.6 |

| Batch | 50 pcs/month |

For this application, a machine with **Ø500 mm or larger swing over bed** can be considered, but the actual setup must also confirm swing over carriage, chuck capacity and tool clearance.

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# 3. Process

A flat bed CNC lathe can complete multiple turning processes in one setup.

|---|:---:|:---:|:---:|

| OD Turning | ✓ | ✓ | ✓ |

| Facing | ✓ | ✓ | ✓ |

| ID Boring | Optional | ✓ | ✓ |

| Grooving | ✓ | ✓ | ✓ |

| Contour Turning | ✓ | ✓ | ✓ |

## Typical Shaft Process

For a Ø120 × 1000 mm 40Cr shaft:

**Clamping → Facing → Rough OD Turning → Finish OD Turning → Grooving → Threading → Inspection**

For long shafts, the tailstock supports the free end and helps reduce workpiece deflection.

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## Typical Flange Process

For a Ø450 × 80 mm 316 stainless steel flange:

**Clamping → Facing → Rough OD Turning → Finish OD Turning → ID Boring → Grooving → Inspection**

Because stainless steel has relatively high cutting resistance and poor heat dissipation, machine rigidity, suitable cutting tools and coolant are important.

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# 4. Machine Requirement

The same flat bed CNC lathe is not suitable for every shaft, disc and flange.

## Key Parameters

| Parameter | Why It Matters |

|---|---|

| Swing over bed | Determines general diameter clearance |

| Swing over carriage | Determines diameter clearance above carriage |

| Max. workpiece length | Determines whether long shafts fit |

| Max. turning length | Determines actual machinable length |

| Spindle bore | Important for bars and pipes |

| Chuck size | Determines workholding capability |

| Guideway width | Related to rigidity and load capacity |

| Spindle speed | Important for different diameters/materials |

| Main motor power | Important for cutting capacity |

| Tailstock | Supports long workpieces |

| Steady rest | Supports long/heavy shafts |

| Turret | Determines tool capacity and change efficiency |

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## Which Parameter Is Most Important?

It depends on the workpiece.

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

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## What Spindle Bore Size Do I Need for a 3-Inch Pipe?

This is different from machining a solid shaft or flange.

A standard **NPS 3 pipe has an outside diameter of approximately 88.9 mm**.

If the pipe needs to pass completely through the spindle:

**Spindle bore must be larger than Ø88.9 mm**, with additional clearance for convenient loading.

For frequent pipe machining, a dedicated **CNC pipe threading lathe** may be more suitable than a standard flat bed CNC lathe.

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# 5. Recommended Model

Anyang Xinheng provides flat bed CNC lathes ranging from compact CNC machines for small components to large machines for shafts, rollers and heavy industrial parts.

## Recommended Models by Workpiece

| Model | Swing Over Bed | Typical Application |

|---|---:|---|

| CK0640 | Ø300 mm | Small shafts and compact components |

| CKD6140 | Ø400 mm | Small/medium shafts and sleeves |

| CKQ6150 | Ø500 mm | Shafts, discs and medium flanges |

| CKQ6166 | Ø660 mm | Larger shafts, discs and flanges |

| CKQ6180 | Ø800 mm | Large-diameter components |

| CK6163 | Ø630 mm | Medium/large industrial shafts |

| CK6180 | Ø800 mm | Large shafts and rollers |

| CKB61100 | Ø1000 mm | Large industrial components |

| CKBP61125 | Ø1250 mm | Large-diameter heavy workpieces |

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## Recommended Model for Small Shaft Machining

### CK0640 CNC Lathe

A typical application is:

| Parameter | Example |

|---|---:|

| Workpiece | Small precision shaft |

| Material | 45# Steel |

| OD | Ø35 mm |

| Length | 150 mm |

| Process | Facing + OD turning + grooving + threading |

CK0640 machine capacity includes:

| Parameter | Value |

|---|---:|

| Swing over bed | Ø300 mm |

| Swing over carriage | Ø110 mm |

| Max. workpiece length | 180 mm |

| Spindle bore | Ø40 mm |

| Spindle speed | Up to 3000 rpm |

This configuration is more suitable for **small-part batch production** than selecting an unnecessarily large machine.

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## Recommended Model for Shaft and Flange Machining

### CKQ6150 CNC Lathe

The CKQ6150 provides:

| Parameter | Value |

|---|---:|

| Swing over bed | Ø500 mm |

| Swing over carriage | Ø280 mm |

| Guideway width | 400 mm |

| Standard chuck | Ø250 mm |

| Main motor | 7.5 kW |

It can be considered for medium-size shafts, sleeves and disc-type components.

For example:

**Workpiece: 40Cr shaft, Ø180 × 1200 mm**

**Workpiece: 316 stainless steel flange, Ø450 × 80 mm**

The final configuration should be confirmed according to the actual drawing, clamping method and machining allowance.

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## Recommended Model for Large Shaft Machining

For large shafts and rollers, a heavier flat bed CNC lathe is required.

Anyang Xinheng's **550/600 mm guideway CNC lathe series** covers workpiece diameters from approximately Ø630 mm upward, with industrial configurations for larger shafts, pipes and cylindrical components.

Typical models include:

| Model | Swing Over Bed | Suitable Workpiece |

|---|---:|---|

| CK6163 | Ø630 mm | Medium/large shaft |

| CK6180 | Ø800 mm | Large shaft / roller |

| CKB61100 | Ø1000 mm | Large industrial component |

| CKBP61125 | Ø1250 mm | Heavy large-diameter component |

This series can be configured for heavier workpieces where **rigidity, workpiece weight and turning length** are more important than high spindle speed.

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# Which Flat Bed CNC Lathe Should I Choose?

Use the workpiece drawing as the starting point.

### Example A

**40Cr shaft: Ø120 × 1000 mm**

Priority:

1. Workpiece length

2. Tailstock

3. Turning length

4. Swing over carriage

A medium flat bed CNC lathe can be considered.

### Example B

**316 stainless steel flange: Ø450 × 80 mm**

Priority:

1. Swing over bed

2. Chuck capacity

3. Swing over carriage

4. Boring capability

A machine such as the **CKQ6150** can be considered after checking the actual clamping setup.

### Example C

**42CrMo industrial roller: Ø720 × 2500 mm**

Priority:

1. Swing over bed

2. Workpiece weight

3. Turning length

4. Guideway rigidity

5. Tailstock / steady rest

6. Main motor power

A larger **550/600 mm guideway flat bed CNC lathe**, such as the CK6180 series, is more appropriate.

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# Final Selection Checklist

Before selecting a flat bed CNC lathe, provide:

| Information | Example |

|---|---|

| Workpiece type | Shaft |

| Material | 42CrMo |

| Maximum OD | Ø500 mm |

| Length | 2500 mm |

| Weight | 1800 kg |

| Process | Rough + finish turning + groove + thread |

| Tolerance | ±0.02 mm |

| Surface finish | Ra 1.6 |

| Quantity | 20 pcs/month |

| CNC system | FANUC / Siemens / GSK |

| Drawing | Recommended |

A machine should not be selected from **swing over bed alone**.

For accurate selection, always compare:

**Diameter + Length + Weight + Material + Process + Tolerance + Production Quantity**