Used Heller Bea 2 for sale (71)

Condition: ready for operation (used), Year of construction: 1999, Main Drive Psdpoxu Rwaefx Adijrd Spindle speed range 10000 Number of axis 4 Tools Number of index 160 Type of tool holder HSK-63A This 4-axis HELLER MC 16-2 was manufactured in 1999. It features a Siemens control system, a robust tool magazine with 160 slots, and an HSK-63A tool holder. The spindle operates at a speed of 10,000 rpm, ideal for detailed machining tasks. If you are looking to get high-quality milling capabilities, consider the HELLER MC 16-2 machine we have for sale. Contact us for more information about this machine. Application Types Milling

Condition: used, Year of construction: 2019, operating hours: 15,551 h, functionality: fully functional, controller manufacturer: Siemens, controller model: SINUMERIK 840D sl, General Year of manufacture: 2019 Operating hours: 15,551 Control: SINUMERIK 840D sl Maximum workpiece dimensions Workpiece length up to 600 mm Maximum cutting circle mm 200 Stroke over center mm 100 Maximum clamping diameter mm 110 Tip diameter mm 30 – 60 Working area Longitudinal stroke Z-axis mm 705 Longitudinal stroke Z-/W-axis mm 705 / 705 Cross stroke X-axis mm 180 Cross stroke X-/U-axis mm 180 / 180 Steady Z3-axis depends on the chuck Workpiece C21-/C22-axis degrees 360 Tool Outer diameter mm 700 Tool holder Short cone according to DIN 55026: Size: 8 Theoretical diameter of cone mm: 139,735 Tool drum bearing diameter in the front bearing: 160 mm Chuck mount: 180 mm Chuck diameter up to 260 mm Workpiece spindle bearing diameter in the front bearing: 170 mm Guidance system for machining units: Rolling guides with rollers, size 55 Psdjwgm Hkopfx Adijrd Spindle Maximum power at 100% load: 24 kW Spindle speed: 0-2000

Condition: good (used), BJ. 1999+2001 Combined Crankshaft Machining Combination of centric turning and eccentric milling operations on two machines connected via a shared chip conveyor with a single chip discharge. Siemens 840D control system Tool holder - Heller Nominal tool diameter Ø700 - tools are not included but can be purchased or newly acquired for an additional charge. NC-controlled steady rest for milling operations 3-jaw chucks on both sides from Blessing with integrated alignment arms Both machines with automatic loading hatch from above with a loading interface or for manual loading. The machines are currently still in series production and can be inspected under power. Installation of components is possible upon request for an additional charge, with documentation of the interchangeable parts and tools. Safety lock for the control system and drives included - free location. Availability upon request, warranty excluded. Year of Production: 1999+2001 Combination of concentric turning. and eccentric Milling Operations in 2 separate machines, which are linked through a common chip conveyor with high drop-off Machine control: Siemens 840D Tool Adapter - Brighter Tooling diameter Ø700 nominal - Tooling is not subject might be subject for separate purchase or new from supplier NC controlled support with pads both sides 3-jaw-chucks from Company Blessing with integrated equalizing device automatic Gantry door for overhead loading and corresponding interface or manual loading also possible Machines are actually in serial production and can be inspected upon request set-up of individual parts possible for separate oncost including documentation of change-over parts and tooling safeguarding of control and drives included - free location Predpev I Ab Ujfx Adijd availability on agreement, no warranty possible

Condition: used, Technical characteristics: HORIZONTAL MACHINING CENTER Prjdpfxe Dvlxo Adied AUTOFEED 8 PALLETS 140 TOOL ISO50

Condition: used, Year of construction: 2017, turning length: 500 mm, spindle motor power: 30,000 W, General Year of manufacture: 2017 Control: SINUMERIK 840D sl Maximum workpiece dimensions Workpiece length up to 500 mm Maximum cutting radius mm 200 Stroke over center mm 25 Maximum clamping diameter mm 100 Tip diameter mm 30 – 60 Working area Longitudinal stroke Z-axis mm 602 Longitudinal stroke Z-/W-axis mm 602 / 602 Cross stroke X-axis mm 140 Cross stroke X-/U-axis mm 140 Steady Z3-axis depends on the chuck Workpiece C21-/C22-axis degrees 360 Tool Outer diameter mm 230 Tool holder Quick-change system Bearing diameter of tool drum in the front bearing mm 660 * 790 Chuck holder Cylindrical mm 180 Chuck diameter up to mm 260 Workpiece spindle bearing diameter in the front bearing mm 170 Guidance system for machining units Rolling guides with rollers, size 45 Feed drives Cross slide adjustment W-axis, Z-axis 100% duty cycle Nm 18 / 18 Prjdpfowgndkex Adied Tool feed U-axis, X-axis 100% duty cycle Nm 18 / 18 Steady Z3-axis 100% duty cycle Nm 10.5 Vise right Z4-axis 100% duty cycle Nm 10.5 Circular feed workpiece C21- axis, C22-axis 100% duty cycle Nm 18 / 18 Axis speed Feed/rapid traverse speed longitudinal W-, Z-, and Z3-axes m/min 0 - 40 Feed/rapid traverse speed transverse U-axis, X-axis m/min 0 - 20 Feed/rapid traverse speed Z3-axis (steady rest) m/min 0 - 40 Circular feed of workpiece C21-axis, C22-axis rpm 0 - 60 Cutter drive Power per unit (nominal / maximum) kW 15 / 30 Cutting speed m/min 120 - 255 Tool torque Nm 1500

Condition: used, Year of construction: 2019, operating hours: 17,529 h, turning length: 500 mm, spindle motor power: 30,000 W, General Year of manufacture: 2017 Operating hours: 17,529 Control: SINUMERIK 840D sl Maximum workpiece dimensions Workpiece length up to 500 mm Maximum cutting radius mm 200 Stroke over center mm 25 Maximum clamping diameter mm 100 Tip diameter mm 30 – 60 Working area Longitudinal stroke Z-axis mm 602 Longitudinal stroke Z-/W-axis mm 602 / 602 Cross stroke X-axis mm 140 Cross stroke X-/U-axis mm 140 Steady Z3-axis depends on the chuck Workpiece C21-/C22-axis degrees 360 Tool Outer diameter mm 230 Tool holder Quick-change system Bearing diameter of tool drum in the front bearing mm 660 * 790 Chuck holder Cylindrical mm 180 Chuck diameter up to mm 260 Workpiece spindle bearing diameter in the front bearing mm 170 Guidance system for machining units Rolling guides with rollers, size 45 Feed drives Cross slide adjustment W-axis, Z-axis 100% duty cycle Nm 18 / 18 Tool feed U-axis, X-axis 100% duty cycle Nm 18 / 18 Steady Z3-axis 100% duty cycle Nm 10.5 Vise right Z4-axis 100% duty cycle Nm 10.5 Circular feed workpiece C21- axis, C22-axis 100% duty cycle Nm 18 / 18 Axis speed Feed/rapid traverse speed longitudinal W-, Z-, and Z3-axes m/min 0 - 40 Feed/rapid traverse speed transverse U-axis, X-axis m/min 0 - 20 Feed/rapid traverse speed Z3-axis (steady rest) m/min 0 - 40 Predpfxjwgnigs Adiod Circular feed of workpiece C21- axis, C22-axis rpm 0 - 60 Cutter drive Power per unit (nominal / maximum) kW 15 / 30 Cutting speed m/min 120 - 255 Tool torque Nm 1500

Condition: used, Year of construction: 2019, operating hours: 17,349 h, turning length: 500 mm, spindle motor power: 30,000 W, General Year of manufacture: 2017 Operating hours: 17,349 Control: SINUMERIK 840D sl Maximum workpiece dimensions Workpiece length up to 500 mm Maximum cutting radius mm 200 Stroke over center mm 25 Maximum clamping diameter mm 100 Tip diameter mm 30 – 60 Working area Longitudinal stroke Z-axis mm 602 Longitudinal stroke Z-/W-axis mm 602 / 602 Cross stroke X-axis mm 140 Cross stroke X-/U-axis mm 140 Steady Z3-axis depends on the chuck Workpiece C21/C22 axis degrees 360 Tool Outer diameter mm 230 Tool holder Quick-change system Bearing diameter of tool drum in the front bearing mm 660 * 790 Chuck holder Cylindrical mm 180 Chuck diameter up to mm 260 Workpiece spindle bearing diameter in the front bearing mm 170 Prsdowgnfuepfx Adied Guidance system for machining units Rolling guides with rollers, size 45 Feed drives Cross slide adjustment W-axis, Z-axis 100% duty cycle Nm 18 / 18 Tool feed U-axis, X-axis 100% duty cycle Nm 18 / 18 Steady Z3-axis 100% duty cycle Nm 10.5 Vise right Z4-axis 100% duty cycle Nm 10.5 Circular feed workpiece C21- axis, C22-axis 100% duty cycle Nm 18 / 18 Axis speed Feed/rapid traverse speed longitudinal W-, Z-, and Z3-axes m/min 0 - 40 Feed/rapid traverse speed transverse U-axis, X-axis m/min 0 - 20 Feed/rapid traverse speed Z3-axis (steady rest) m/min 0 - 40 Circular feed of workpiece C21- axis, C22-axis rpm 0 - 60 Cutter drive Power per unit (nominal / maximum) kW 15 / 30 Cutting speed m/min 120 - 255 Tool torque Nm 1500

Condition: used, Year of construction: 2016, operating hours: 60,000 h, functionality: fully functional, Heller FMS with 2 x H2000 Machine make / type: HELLER H2000 Operating hours: 59,654 Year of manufacture: 2016 Control system: Siemens 840D SL Spindle: PC63 10,000 rpm, 38 kW, 242 Nm Predpfswbt Rrsx Adiod Tool clamping system: SK40 Magazine / locations: Chain magazine / 160 locations Convenient operator terminal, setup during machining Rotary table: 360,000° x 0.001° Coolant system: Knoll KF 400/50 bar Working area XYZ (mm): 630 / 630 / 630 Pallet size (mm): 500 x 400 Workpiece clamping: Mechanical Additional options, special features: Drill breakage detection (SBBK); FMS interface, infrared receiver probe (Renishaw), extraction interface; coolant cooler Machine make / type: HELLER H2000 Operating hours: 60,546 Year of manufacture: 2016 Control system: Siemens 840D SL Spindle: SC63 16,000 rpm, 40 kW, 96 Nm Tool clamping system: SK40 Magazine / locations: Chain magazine / 240 locations Convenient operator terminal, setup during machining Rotary table: 360,000° x 0.001° Coolant system: Knoll KF 400/50 bar Working area XYZ (mm): 630 / 630 / 630 Pallet size (mm): 500 x 400 Workpiece clamping: Mechanical Additional options, special features: Drill breakage detection (SBBK); FMS interface, infrared receiver probe (Renishaw), extraction interface; coolant cooler Machine make/type FASTEMS FPC750 with expansion container Operating hours: No counter installed Year of manufacture: 2016 Control system: FASTEMS Memory locations: 24 memory locations, 2 setup stations Workpiece clamping: Mechanical Additional options, special features: 20 pallets included Further information and technical specifications upon request.

Condition: ready for operation (used), Year of construction: 2016, Control Unit Brand SIEMENS Model 840D sl Main Drive Spindle speed range 9000 Stroke 200 mm Prjdpjw Tnn Ujfx Adied Number of axis 3 This 3-axis HELLER PT 16 was manufactured in 2016. It features a multifunction spindle driven by a compact servo motor, achieving speeds up to 15 m/min and a maximum of 9,000 rpm. The machine offers a 200mm stroke in 3 axes with ball rail guides and screws for enhanced precision. Consider the opportunity to buy this HELLER PT 16 CNC milling machine. Contact us for more information about this machine. Application Types Milling

Condition: excellent (used), Year of construction: 2007, Control: Siemens 840D powerline Travel paths X/Y/Z: 630/630/630 mm 2-fold pallet changer Spindle speed: 10,000 rpm Knoll coolant system with paper band filter Tool holder: SK40 Prjdpfx Adoxy S Aujied Tool magazine with 80 stations

Condition: used, Year of construction: 2005, Technical details: x-travel: 2200 mm y-travel: 2200 mm z-travel: 1400 mm spindle taper ISO: 50 spindle diameter in front bearing: 110 mm spindle turning speed range: 45 - 6000 U/min pallet table size: 1000 x 1250 mm Pedovgmitopfx Adisrd pallet worktable capacity: 6000 kg feed range: 1 - 60000 rapid traverse: 60 m/min spindle drive motor: 27 kW dimensions of the machine ca.: 15 x 8,5 x 5,7 m total power requirement: 133 kVA weight of the machine ca.: 50 t Machine with SIEMENS 840 D control - full B-axis - palette changer for 3 palettes - tool changer for 244 tools - coolant through spindle - max. workpiece swing 2200 mm *

Condition: good (used), Year of construction: 2011, Ref. -No.: 10598 Manufacturer: HELLER Type: MC 2000 Year of construction: 2011 Type of control: CNC Control: Siemens 840 D sl Storage location: Halberstadt Country of origin: Hermany Machine-No.: 50XXXX X-Travel: 800 mm Y-Travel: 800 mm Z-Travel: 1000 mm Work spindle torque (25% ED): 242 Nm Tool Taper: SK 40 Numbers Of Tools In Magazin: 54 Tool Piece Magazine With: 80 Pcs./pcs. Turning Speeds: 10000 RPM Drive Capacity - Spindle Motor: 17 kW High-Pressure Pump: 50 bar Speed range - main spindle: 10000 RPM Numbers Of Pallets: 2 Size Of Pallet: 630 x 500 mm Weight Of The Machine Ca.: 13000 t spindle running time: 7000 H Operating hours: 14000 H Preparation area: 4 x 90° hydraulic pressure: 200 bar Further information: - The machine has been measured - The geometry is in excellent condition - The spindle runs a little rough - Clamping towers and cutting tool holders are also included - 2 additional clamping towers - 2 replacement pallets - 2-axis servo tool changer - Scraper conveyor for dry machining Pjdpfx Adjxvw Rpeisrd - Cold light in the work area - Central cooling unit for motor spindle and control cabinet - Control unit at the workpiece setup station - NC-controlled rotary table - Clamping hydraulics The machine can be viewed under power by appointment.

Condition: used, Year of construction: 2002, Technical details: x-travel: 1000 mm y-travel: 800 mm z-travel: 1100 mm weight of the machine ca.: 20 t dimensions of the machine ca.: 6,80 x 3,0 x 3,20 m Tool bore: SK50 Tool taper: HSK-A 100 Pedpfx Aew T Tntedijrd turning speed range: 45-6.000 U/min size of pallet: 630x800 mm change time of pallets: 21 sec Mechanical processing of cylinder heads and cylinder crankcases Machines have been in single-shift operation since 2013 Service and maintenance intervals were adhered to *

Condition: used, Year of construction: 2007, operating hours: 40,933 h, functionality: fully functional, travel distance X-axis: 1,000 mm, travel distance Y-axis: 1,000 mm, travel distance Z-axis: 1,000 mm, controller manufacturer: Siemens, controller model: 840D PL, table width: 630 mm, table length: 630 mm, spindle speed (max.): 8,000 rpm, number of spindles: 1, Machine name / type: HELLER / MCH 280 C Psdpfx Adsxwpmxeijrd Operating hours: 40.933h Year of construction: 2007 Control unit: Siemens 840D PL Spindle: 8.000 rpm (43 kW/ 822 Nm) Tool clamping system: HSK 100 Tool magazine / places (Options): Rack / 234 (Operating panel at the tool loading station with terminal) Rotary table: 360.000° X 0,001° Coolant unit: KNOLL, VRF 250, IKZ 70 bar, (work area flushing) Positioning range XYZ (mm): 100 / 1000 / 1000 Pallet size (mm): 630 X 630 Workpiece clamping: mechanical Additonal options: Receiver for measuring probe (RENISHAW); interface exhaust system; additional weight for pallets; drill fracture sensing; status lamp; interface exhaust system; integrated tool and collision monitoring; toolshaft cleaning; tool codechip; Interface handheld;

Condition: ready for operation (used), Year of construction: 2017, operating hours: 1,000 h, Control Unit Brand SIEMENS Model 840D Tools Type of tool holder SK 40 DIN 69 871 Pedpfx Adoxy Tipoijrd Additional Equipment Operating voltage: 400 V, 50 Hz This HELLER H2000 was manufactured in 2017. It features a robust SIEMENS 840D solution line control system and a tool magazine with 80 positions. The machine includes a NC rotary table and a coolant purification system with a 50 bar internal supply. Ideal for precision machining with its advanced spindle technology and 3,000 operating hours. Consider the opportunity to buy this HELLER H2000 horizontal machining centre. Contact us for more information about this machine. Application Types Milling

Year of construction: 1997, condition: good (used), Control uni-Pro CNC 90 Psdpfxslkgfae Adiord Travel X/Y/Z 800/800/710 mm Spindle speed 4500 rpm Tool magazine for 52+120 tools SK 50 Indexing table 1° 4-fold pallet changer 500x630 mm chip conveyor

Condition: used, Year of construction: 2002, Technical details: Psdpfxevgmiyj Adierd x-travel: 630 mm y-travel: 630 mm z-travel: 630 mm pallet size:: 400 x 500 mm spindle taper:: HSK 63 spindle turning speed - stepless: 10 - 16000 U/min total power requirement: 55 kW weight of the machine ca.: 11 t Machine with SIEMENS 840 D control for 4 axis - digital drives - palette changer 4-fold - tool changer 160-fold - coolant device with coolant through spindle - full B-axis - chip conveyor - hydr. workpiece clamping *

Condition: good (used), Year of construction: 2017, Ref. -No.: 10596 Manufacturer: HELLER Type: H - 2000 Year of construction: 2017 Type of control: CNC Control: Siemens 840 D Storage location: Halberstadt Country of origin: Germany Machine-No.: 56XXX X-Travel: 630 mm Y-Travel: 630 mm Z-Travel: 630 mm B-Axis: 0,001 ° Table Load: 500 kg Max. Tool Length: 350 mm Max. Tool Diameter: 160 mm Tool Taper: HSK 63 Numbers Of Tools In Magazin: 80 Turning Speeds: 16000 RPM Tool changer: Doppelgreifer Max. Workpiece height: 850 mm Max. Torque: 95 Nm Rapid Travel X/Y/Z: 60 mm / min Rapid Traverse X-Axis: 80 m / min Rapid Travel Y-Axis: 80 m / min Rapid Traverse Z-Axis: 90 m / min Pedpfx Adexvw Risierd Drive Capacity - Spindle Motor: 40 kW Internal cooling: 50 bar Numbers Of Pallets: 2 Size Of Pallet: 400 x 500 mm spindle running time: 1000 H Operating hours: 3000 H Workpiece interference circuit max.: 720 mm Media interface: 5 - fach Further information: - Equipped with NC rotary table. - State-of-the-art spindle technology. - Ideal for precise machining tasks. - Spindle hours: 1000. - Pallet can be rotated manually 4 x 90 - Hydraulic pressure 200 bar - Quick drill breakage check Machine can be viewed under power by arrangement

Condition: like new (used), Year of construction: 2023, operating hours: 200 h, functionality: fully functional, travel distance X-axis: 1,000 mm, travel distance Y-axis: 1,000 mm, travel distance Z-axis: 1,000 mm, rapid traverse X-axis: 50 m/min, rapid traverse Y-axis: 50 m/min, rapid traverse Z-axis: 50 m/min, feed length X-axis: 1,000 mm, feed length Y-axis: 1,000 mm, feed length Z-axis: 1,000 mm, feed rate X-axis: 50 m/min, feed rate Y-axis: 50 m/min, feed rate Z-axis: 50 m/min, controller manufacturer: Siemens, controller model: Siemens 840d solution line SL, workpiece length (max.): 900 mm, workpiece width (max.): 900 mm, workpiece height (max.): 900 mm, workpiece diameter (max.): 900 mm, table width: 630 mm, table length: 630 mm, table load: 850 kg, overall weight: 16,000 kg, spindle speed (min.): 5,000 rpm, spindle speed (max.): 8,000 rpm, operating hours of spindle: 960 h, coolant supply: 70 bar, spindle motor power: 43,000 W, spindle nose: HSK100, number of spindles: 1, input voltage: 400 V, type of input current: AC, Equipment: chip conveyor, rotational speed infinitely variable, List price new: €749,000 Psdsxzh Ebspfx Adisrd HSK100, the machine is in like-new condition and has not yet produced any series parts. So far, only one component has been sampled.

Condition: used, Year of construction: 2008, operating hours: 61,112 h, functionality: fully functional, travel distance X-axis: 800 mm, travel distance Y-axis: 800 mm, travel distance Z-axis: 800 mm, controller manufacturer: Siemens, controller model: 840D PL, table width: 630 mm, table length: 630 mm, spindle speed (max.): 6,000 rpm, number of spindles: 1, Machine name / type: HELLER / MCH 250 with RSP Operating hours: 61112 Year of construction: 2008 Control unit: Siemens 840D PL Spindle: 6.000 rpm Tool clamping system: HSK 100 Tool magazine / places: Rack / 234 Prsdpfx Aexwpi Todied Rotary table: 360.000° X 0,001° Coolant unit: KNOLL, VRF 250, IKZ 70 bar, (work area flushing) Positioning range XYZ (mm): 800 / 800 / 800 Pallet size (mm): 630 X 630 Workpiece clamping: mechanical Additonal options: Fast drill fracture sensing (SBBK); interface exhaust system; screen blow-off device for operator door; alternative strategy; Integrated process monitoring (IPM) and collision monitoring; 3 colour status lamp; RSP 4-fach; tool cleaning; MCIS TDI tool planning; Feed force display; MCIS DNC; spline-interpolation; cycle 800;

Condition: ready for operation (used), Year of construction: 2004, operating hours: 28,349 h, Main Drive Number of axis 4 Spindle Speed 12000 RPM Pedpfx Asxyaz Eediord Tool taper HSK 63 This 4-axis HELLER MC 12 horizontal machining center was manufactured in 2004. It features a tool holder with HSK 63, a hydraulic workpiece clamping system at 60 bar, and a spindle speed of 12,000 rpm. The machine includes a 42-position tool changer and an NC rotary table. If you are looking to get high-quality milling capabilities, consider the HELLER MC 12 machine we have for sale. Contact us for more information about this machine. Application Types Milling

Condition: new, Heller CPU91 CNC G 23 Uni Pro CNC 90 Board used 100 % functional Pedpfx Adei Ea E Aoisrd

Condition: used, Year of construction: 1999, cutting diameter max 400 mm mit Sägeblättern weight of the machine ca. 1,4 t Podpfx Adow Sygmsijrd

Condition: excellent (used), Year of construction: 2022, operating hours: 6,740 h, functionality: fully functional, travel distance X-axis: 900 mm, travel distance Y-axis: 950 mm, travel distance Z-axis: 930 mm, torque: 400 Nm, controller manufacturer: Siemens, controller model: 840D SL, table width: 630 mm, table length: 500 mm, spindle speed (max.): 12,000 rpm, spindle motor power: 45,000 W, number of spindles: 1, Machine name / type: HELLER / HF 5500 APC MT Operating hours / usage time: 6740 / 1181 Year of construction: 2022 Control unit: Siemens 840D SL Spindle: HSU DC 100i; 12.000 rpm, 45 kW, 400 Nm Tool clamping system: HSK 100 Predpfexwng Rjx Adiod Tool magazine / places: Chain / 50 Rotary table: 360.000° X 0,001° Coolant unit: KNOLL, VRF 250, IKZ 70 bar (work area flushing) Positioning range XYZ (mm): 900 / 950 / 930 Pallet size (mm): 500 X 630 Workpiece clamping: 80 bar Sonder Additional options / specifics: HELLER facing slide unit Receiver for measuring probe (RENISHAW) Coolant temperature control Interface for exhaust system 3 colour status lamp Work area flush Hinge band conveyor for wet machining Fast drill fracture sensing (SBBK) Multi-spindle-head support (MSK) Thermal growth compensation Thermal growth correction in linear axis Working area camera Tool measurement (BLUM) AutoCal, AutoSet Robot interface Tool pickup manual

Condition: ready for operation (used), Year of construction: 2011, Control Unit Brand SIEMENS Main Drive Spindle speed range 10000 Spindle motor power 17 kW Predpfx Adsxuay Djisd Number of axis 3 Additional Equipment Scraper belt conveyor for dry machining Cold light in the work area Central cooling unit for motor spindle and control cabinet, CFC-free This 3-axis HELLER MC 2000 was manufactured in 2011 and features a robust three-phase motor spindle, delivering 17 kW at 10,000 rpm with a SK 40 tool holder. It includes a 2-axis servo tool changer, a stationary tool magazine with 54 positions, and a pallet changing device with 2 pallet positions. If you are looking to get high-quality milling capabilities, consider the HELLER MC 2000 machine we have for sale. Contact us for more information about this machine. Application Types Milling