CNC Turning

Precision Machining of Rotating Components

Professional CNC turning services for demanding industrial applications

ZDANMILL specializes in precision CNC turning of metals and plastics, with its headquarters in the Greater Poland region. We provide comprehensive machining of rotational components, from single prototypes to full production series for the automotive, machinery, energy, and other industrial sectors. Our modern CNC lathes and experienced team of operators guarantee machining accuracy of up to ±0.01 mm.

What is CNC Turning?

CNC turning (Computer Numerical Control) is a machining process in which material is removed by a stationary cutting tool (lathe tool), while the workpiece rotates. This process enables the production of axially symmetrical parts with the highest precision and repeatability.

Key features of CNC turning:

  • The workpiece rotates in the lathe chuck
  • The cutting tool moves linearly along and across the axis of rotation
  • Ideal for the production of shafts, axles, bushings, and rings
  • High precision in diameter and length tolerances
  • Capability to machine threads, tapers, and radii
  • Automation based on programmed G-code

Turning of structural and alloy steels

Structural steel is a fundamental material for machine parts requiring high strength and rigidity.

 

Steel grades we turn:

  • C45, C45E – most popular steel for shafts and axles

  • 42CrMo4, 41Cr4 – chromium-molybdenum alloy steel (high load applications)

  • S235, S355 – structural steel for welded components

  • 18HGT, 16MnCr5 – case hardening and hardening steels

  • 34CrNiMo6 – alloy steel for heavily loaded components

 

Applications:

  • Drive shafts and cardan shafts

  • Bearing journal shafts

  • Loaded pins and bolts

  • Machine spindles

  • Tool shanks

 

Heat treatment: We turn components before heat treatment (hardening, case hardening, nitriding) with appropriate allowance:

  • Ø up to 30mm: 0.3-0.5mm on diameter (0.15-0.25mm per side)

  • Ø 30-60mm: 0.5-0.8mm on diameter

  • Ø over 60mm: 0.8-1.2mm on diameterFollowing heat treatment, finishing grinding is available to achieve required tolerances.

Precision: Shaft tolerances h6, h7, h8 (0/+0.01mm, 0/-0.01mm)

Stainless Steel for CNC Machining

Stainless steel requires specialized machining parameters due to its tendency to work-harden.

 

Stainless steel grades:

  • 304 (1.4301) / 304L (1.4307) – universal austenitic steel, L version with reduced carbon content

  • 316 (1.4401) / 316L (1.4404) – acid-resistant steel with molybdenum, chloride resistant

  • 303 (1.4305) – free-cutting steel with increased sulfur content (improved machinability)

  • 430 (1.4016) – ferritic steel (magnetic, lower corrosion resistance)

Applications:

  • Pump shafts for chemical industry

  • Axles for food industry

  • Pins for marine industry

  • Sealing sleeves

  • Laboratory equipment components

Specifics of stainless steel turning:

  • Cutting speeds 50-120 m/min (depending on grade and carbide inserts)

  • Sharp tools with coated carbide inserts (TiN, TiAlN)

  • Intensive cooling (cutting fluid at high pressure)

  • Experienced operator (risk of work-hardening of the surface layer)

  • Continuous feed without interruptions (avoiding work-hardening)

Surface treatment: After turning, chemical passivation is available (restoring corrosion resistance after mechanical machining).

 

Precision: Tolerances to ±0.02mm, surface roughness Ra 1.6-3.2 µm

Aluminium for CNC Machining

Aluminium is a material with excellent machinability, low weight and good mechanical properties.

 

Aluminium alloys we turn:

  • Al 2024, 7075 – high strength (aerospace, sports)

  • Al 6082, 6060 – universal applications

  • Al 5083 – corrosion resistance (marine industry)

  • Al 2011 – free-cutting alloy (best machinability)

Applications:

  • Shafts for lightweight structures

  • Axles for aerospace industry

  • Spacer sleeves and adapters

  • Machine tool shanks

  • Electronic components

Advantages of aluminium turning:

  • Very high machining speeds (200-500 m/min)

  • Excellent surface finish (Ra 1.6-3.2 µm after finishing turning, Ra 0.4-0.8 µm after polishing)

  • Possibility of thin walls

  • Low cutting forces

  • Possibility of anodizing after machining

Precision: Tolerances to ±0.01mm, possibility of very smooth surfaces

Non-Ferrous Metals for CNC Machining

Non-ferrous metals with excellent conductivity and easy machinability.

 

Applications:

  • Electrical shanks (copper)

  • Sliding sleeves (bronze)

  • Installation fittings (brass)

  • Adjustment screws

  • Decorative components

Advantages:

  • Very good machinability

  • High surface quality

  • Possibility of polishing

  • Quick machining

Free-cutting brass CuZn39Pb3 (CW614N):

  • Best for turning (lead additive 2-3%)

  • Excellent machinability (Class I according to PN)

  • Ideal threads and grooves (short, brittle chip)

  • Applications: fittings, connectors, electrical components

Bronze:

  • Excellent sliding properties

  • Wear resistance

  • Applications: bearing sleeves, sliding gear elements

Polymers for CNC Machining

Polymers require specialized knowledge of material properties and machining parameters.

 

Engineering plastics:

  • Polyamide PA6, PA66 – gears, guides, structural components

  • Polyoxymethylene POM-C – sleeves, sliding bearings, precision gears

  • Polycarbonate PC – transparent components, housings

  • Polyethylene PE-HD, PE-UHMW – sleeves with lowest friction

Specialist plastics:

  • PEEK – high continuous operating temperature up to 250°C (short-term up to 310°C), aerospace/medical industry

  • PTFE (Teflon) – lowest coefficient of friction, chemical resistance

  • PPS – thermal and chemical stability

Challenges in polymer turning:

  • Low melting temperature (temperature control)

  • Tendency to deformation (minimal clamping forces)

  • Proper tools (large rake angles, sharp edges)

  • Special cooling (compressed air or no cooling)

  • Dimensional stabilization after machining

Applications:

  • Sliding sleeves and bearings (POM, PTFE, PE-UHMW)

  • Gears (PA6, POM)

  • Guides and sliders (PA6, PE-UHMW)

  • Seals and rings (PTFE, PE)

  • Insulators (PEEK, PPS, PC)

  • Medical components (PEEK)

Precision:

Tolerances ±0.05-0.1mm depending on:

  • Type of material (amorphous vs. semi-crystalline)

  • Component size

  • Operating conditions

Note: Hygroscopic materials (PA6, PA66) require accounting for dimensional changes after moisture saturation (up to +0.5-1.5%)

Our offer

Send inquiry

📧 Email: biuro@zdanmill.pl

📞 Telephone: +48 693 672 266

✅ Quote within 24h

✅ Free consultation

✅ 10+ years of experience

Face Turning (Transverse Turning)

Machining of face surfaces perpendicular to the axis of rotation.

 

Applications:

  • Facing shaft ends

  • Creating steps and shoulders

  • Machining mating surfaces

  • Face grooves and undercuts

Benefits:

  • Surface flatness to 0.02mm

  • Perpendicularity to axis of rotation

  • Smooth surfaces for seals

Taper and Radius Turning

Creating tapered surfaces and radii.

 

Applications:

  • Fitted tapers

  • Morse tapers

  • Transitional radii (rounding)

  • Sealing surfaces

Capabilities:

  • Taper angles: any (e.g. 1:10, 1:20, 45°, 60°)

  • Radii: R0.5 – R50 mm

  • High angle accuracy: ±0.1°

Thread Turning

Cutting external and internal threads on a CNC lathe.

Thread types:

  • Metric threads – M6 to M48 (external and internal)

  • Inch threads – UNC, UNF

  • Trapezoidal threads – Tr (screw drives)

  • Multiple threads (multi-start) – Multi-range Tr

  • Special threads – according to technical documentation

  • Thread direction – right-hand (standard) or left-hand

Accuracy classes:

  • Standard: 6g/6H

  • Precision: 5g/5H

  • Loose: 7g/7H

Applications:

  • Screws and spindles

  • Ball screws (gear drives)

  • Threaded connections

  • Adjustment screws

Drilling and Reaming

Machining of axial holes in rotating components.

Capabilities:

  • Drilling holes: Ø1 – Ø40 mm

  • Reaming to tolerances H7, H8

  • Drilling deep holes up to 10×Ø (holes with L/D > 10 require special technology)

  • Countersinking (conical drilling)

  • Tapping holes

 

Applications:

  • Hollow shafts (weight reduction)

  • Holes for pins and dowels

  • Threaded holes

  • Lubrication channels

Grooving and Parting

Creating grooves and cutting off components.

 

Types of grooves:

  • Grooves for retaining rings (DIN 471, 472)

  • Grooves for sealing rings (O-ring)

  • Grooves for feather keys

  • Technological grooves (for thread exit)

  • Decorative grooves

Parting:

  • Cutting finished components from bar stock

  • Minimal material waste

  • Smooth cut surfaces

Example projects:

  • Shafts with grooves for DIN 471 retaining rings

  • Sleeves with grooves for O-rings

  • Series of components cut from Ø20mm bar stock

Industries We Serve

Automotive

Precision turning of components for the automotive industry.

 

Projects:

  • Transmission shafts and cardan shafts

  • Suspension axles and control arms

  • Pins and bolts

  • Sleeves and spacer rings

  • Adjustment spindles

  • Steering system components

Materials: Structural steels (C45, 42CrMo4), hardening steels (16MnCr5), aluminium (7075)

 

Requirements: Highest precision, shaft tolerances h6/h7, full repeatability in production runs

Production of shafts, axles and rotating components for industrial machines.

 

Projects:

  • Drive shafts for machines

  • Axles for rolling and sliding bearings

  • Machine tool spindles

  • Tool shanks

  • Connecting pins

  • Guide sleeves

Materials: Alloy steels, tool steels (hardening after turning), bronzes (sleeves)

 

Features: High strength requirements, assembly precision, production runs

Components for power plants, pumps, turbines, compressors.

 

Projects:

  • Industrial pump shafts

  • Rotor axles

  • Sealing sleeves

  • Pins and bolts for connections

  • Valve and fitting components

Materials: Corrosion-resistant alloy steels, stainless steel 316L, bronzes

 

Requirements: Corrosion resistance, high temperatures, material certificates

Precision components for hydraulic and pneumatic systems.

 

Projects:

  • Cylinder rods

  • Cylinder sleeves

  • Guide pins

  • Valve shafts

  • Distributor components

 

Materials: C45/C45E steels for hard chromium plating (rods), stainless steels, aluminium

 

Features: Smooth surfaces (Ra 0.4-0.8 µm), precise diameter tolerances (h6, h8), possibility of chromium plating

Stainless steel components for production lines.

 

Projects:

  • Mixer and homogenizer shafts

  • Conveyor axles

  • Guide sleeves

  • Dosing pump components

  • Connecting pins

Materials: Stainless steel 304, 316L (material certificates, attestations)

 

Requirements: Compliance with hygiene standards, possibility of passivation, smooth surfaces

Technical Capabilities

Machining Dimensions

Diameters:

  • Minimum: Ø5 mm

  • Maximum: Ø200 mm

  • Most common: Ø10 – Ø80 mm

 

Lengths:

  • Maximum: 500 mm

  • Most common: 20 – 300 mm

Dimensional Tolerances

Shaft diameter tolerances:

  • h6 – ±0.005 – ±0.009 mm (precision bearings)

  • h7 – ±0.007 – ±0.015 mm (standard bearings)

  • h8 – ±0.014 – ±0.027 mm (looser fits)

  • h9 – ±0.025 – ±0.043 mm (free fits)

Hole tolerances (sleeves):

  • H7 – ±0.010 – ±0.015 mm (standard bearings)

  • H8 – ±0.014 – ±0.027 mm (looser fits)

 

Length tolerances:

  • Standard: ±0.1 mm

  • Precision: ±0.05 mm

Surface Roughness

After rough turning: Ra 6.3-12.5 µm

After finishing turning: Ra 1.6-3.2 µm

After precision turning: Ra 0.8-1.6 µm

After polishing: Ra 0.4-0.8 µm

After rough grinding: Ra 0.8-1.6 µm

After precision grinding: Ra 0.2-0.4 µm

After fine grinding: Ra 0.1-0.2 µm

Production Runs

Single-piece production: 1-9 pieces (prototypes, spare parts)

Small series: 10-100 pieces

Medium series: 100-1000 pieces

Large series: above 1000 pieces (price negotiation)