Used Cnc Grinding Machines for sale (64,702)

Year of construction: 2003, condition: excellent (used), Schneeberger DMR Gemini CNC tool grinding machine TECHNICAL DATA Control: GE Fanuc 160, 5 axes simultaneous Software: Schneeberger Quinto Measuring system X,Y and Z axis: 0.1 μm A-axis: 0.0001° C axis: 0.0001° Grinding head Power: 15 kW Kodpfomqni Asx Aanofa speed: 50 - 10`000 rpm spindle nose: HSK 50 Max. wheel diameter: 250 mm Max. Number of grinding wheels: 6 Linear axes X-axis, travel: 380 mm feed speed: 20`000 mm/min resolution: 0,0001 mm gear ratio: 1 : 1 Power: 1,0 kW / 3 Nm Y-axis, travel: 300 mm feed speed: 5`000 mm/min resolution: 0,0001 mm Gear ratio: 24 :4 Power: 1,6 kW / 8 Nm Z-axis, travel: 280 mm feed speed: 20`000 mm/min resolution: 0,0001 mm gear ratio: 1 : 1 Power: 1,0 kW / 3 Nm Rotary axes C-axis: 210 ° Speed: 72 ° / s Resolution: 0,0001 ° Power: 1.6 kW / 8 Nm C` axis: +- 180 ° Speed: 90 ° / s Resolution: 0,0001 ° Infeed: Hydraulic A axis: +- 360 ° Speed: 225 ° / s resolution: 0,0001° Power: 1,0 kW Nose: ISO 50 Center height: 210 mm Dimensions and weight Length: 1700 mm Depth: 2270 mm Height: 2260 mm Weight: 8`000 kg We do not guarantee the accuracy, completeness and timeliness of the information.

Year of construction: 1996, condition: ready for operation (used), Center height: 150mm, max. grinding diameter: 300mm, distance between centers: 620mm, max. workpiece weight: 120kg, grinding head spindle swivel range: +45°/-15°, table adjustment: +/-8.5°, travel X/Z: 160mm/756mm, grinding wheel dimensions X/Y/Z: 400mm/63mm/127mm, grinding wheel speed: 45m/s, workpiece spindle speed: 700rpm. Machine dimensions X/Y/Z: approx. 3000mm/1850mm/1850mm, weight: approx. 3000kg. Including LTA extraction system and SBS wheel balancing device. The workpiece drive is disassembled and its completeness is unknown. Documentation available. An on-site inspection is possible. Ksdsxvdd Aopfx Aanjfa

Condition: ready for operation (used), total height: 2,100 mm, total length: 1,235 mm, total width: 1,500 mm, empty load weight: 1,000 kg, Chevalier FM 3VS X: 762 - Y: 305 - Z: 406 mm Max longitudinal travel X-axe: 762 mm Kodjxpgfcspfx Aanjfa Max cross-travel Y-axe: 305 mm Max travel Z-axe: 406 mm Max height workpiece: 70 > 476 mm Power on spindle: 3 HP Admission in boring head (ISO): ISO 30 Spindlespeeds: 3750 rpm Table size: 1220 x 230 mm

Condition: excellent (used), Grinding range 800 x 600 x 500 mm Ksdpfjr Ezfwex Aanofa Wheel diameter 400 mm Magnetic plate 800 x 600 mm Automatic dresser Automatic balancing device Misc.accessories MARCELS MASCHINEN CH

Condition: as good as new (ex-display), Year of construction: 2025, Centre height: 181 mm Centre distance: 650 mm Maximum grindable workpiece diameter: 360 mm Max. load between centres (cantilevered): 1000 N (100 kg) Max. load between centres: 3000 N (300 kg) Z-axis: Table swivel angle: 10° Table drive, hydraulic: 0-4 m/min X-axis: Infeed spindle travel: 80 mm Rapid traverse (hydraulic): 50 mm Coarse adjustment (air cushion): 280 mm Feed drive by DC motor Rapid feed rate: 48 mm/min/Ø Feed process: plunge grinding / longitudinal grinding 4 preselectable feed rates: mm/min/Ø 0.01–48 4 preselectable infeed amounts: mm 0.001–0.1 Spark-out time, oscillation grinding: 0–99 s / 0–99 strokes Tapping infeed: mm/Ø 0.001 Grinding spindle headstock: universal, swiveling: 0–180° Grinding wheel (external): D x b x d (mm) 500x100x127 or 203.2 Grinding wheel (face - option): D (mm) 250x32x76.2 Grinding wheel (internal - option): D (mm) (2–250) Drive power, external/face: kW 5.5 (7.5) Drive power, internal: kW 2.2 Peripheral speed, external: m/s 35 (50) Grinding wheel wear (external): mm/Ø 160 Guard width: 100 mm Grinding spindle diameter: 60 mm Internal spindle mounting: 80 (100) mm Workpiece headstock: Stepless variable drive: Mk 4, 1/mm 30–270 / 50–450 Workpiece spindle fixable Spindle bore: MK 4/24 mm Spindle nose for flange mounting: MK 4 mm cylindrical Ø63H6 x 6 Ksdpotqf Sqefx Aanefa Workpiece headstock swivel on rotary part: 0–90° Tailstock: Quill mounting / quill diameter: MK 4 / 75 mm Quill stroke: 45 mm Quill force: 100–800 N / 250–1400 N adjustable Quill actuation: manual (foot switch) Quill fine adjustment: ±40 µm Connections: Total connected load (machine): 6.5–10 kW Grinding spindle headstock: 5.5 (7.5) kW Workpiece headstock: 0.55 (1.1) kW Coolant filtration: 0.75–2.2 kW Guideway lubrication pump: 0.1 kW Hydraulic pump: 1.5 kW Hydraulic tank: 80 L Pneumatics: 6 bar Comparable machines: Weiss / EMAG / GP cylindrical grinders / Studer / Kellenberger / Schaudt / Tschudin / Tacchella / Dannobat

Condition: refurbished (used), Year of construction: 2025, (3) Mikrosa SASL 5 CNC (size similar to Kronos M, MX, L) CNC overhaul and retrofit in progress full overhaul and CNC retrofit (pending) komplett Ueberholung + CNC retrofit Grinding wheel 500mm wide x 610mm dia. CNC 5 axis / 5 axis Mikrosa SASL 5 CNC photos of the last finished machine, for reference only complete overhaul and retrofit Grinding wheel 500 x 610 mm Regulating wheel 400 x 650mm Fixed center Complete mechanical overhaul Complete electrical overhaul Elimination of hydraulic movements Application CNC Siemens 840D 5 axes controlled in position with digital brushless motors: - Operating wheel axis motor with optical scale - 4 dressing axes: 2 on the grinding wheel, 2 on the regulating wheel - rotating axis with adjustable speed motor on regulating wheel - rotating axis with 55kW AC motor with inverter on grinding wheel to adjust RPM / peripheral speed (m/sec) Set-up for through-feed grinding and still customizable according to customer needs. Machine refurbished, grinding test in our warehouse is possible, CE certification, manuals, 12 months warranty also available Machines can be inspected in our warehouse in Gussago BS Google Map HERE INFO? . Machine Tools - Machine Tools Gussago (BS) - Italy Tel:  Centerless grinding is a procedure for grinding cylindrical bodies and is used for the mass production of rollers cylindrical, conical rollers, jet needles, pump pistons, hydraulic sliders, crosses, tips, etc. During centerless plunge grinding (plunge grinding), the workpiece is ground in one pass thanks to the translation of the wheel. For this purpose, the grinding wheels and the adjustment discs have a negative profile of the workpiece to work which is given to them with the aid of a tool. Through-feed grinding or also through grinding and longitudinal grinding: parts to be machined proceed uninterruptedly with axial advancement through the grinding gap. Grinding wheel width: 500 Grinding wheel diameter: 610 Kedpfogmf Rnox Aanofa CNC: 5 axis (new)

Year of construction: 1994, condition: good (used), Manufacturer: Rollomatic Year of manufacture: 1994 Ksdpfowhznxjx Aanefa Type: CNC 24-F Machine number: 142 3 x 380 V, 50 Hz

Condition: used, Distance between centres: 1000 mm Centre height: 250 mm B-axis: Accuracy 0.1" CNC brand: Kelco CNC model: 90 Left grinding wheel dimensions (OD x ID x width): Ø400 x Ø127 x 63 mm Kfedpfx Aasxmg Ekjnoa Right grinding wheel dimensions (OD x ID x width): Ø400 x Ø127 x 50 mm Workhead swivel: -30º to +120º Workhead taper: MK 5 Max. workpiece weight between centres: 150 kg Tailstock taper: MK 4 Tailstock quill travel: 50 mm Maximum peripheral speed: 32 m/s High-frequency internal grinding spindle: Ø120 mm High-frequency internal grinding spindle brand: WARNER model K 3.000 Main motor power: 7.5 kW Total power: 26.5 kW Max. Z-axis travel: 1,150 mm Max. Z-axis feed speed: 15 m/min Worktable rotation: 0º to 9º Max. X-axis travel: 320 mm Max. X-axis feed speed: 7.5 m/min Length: 3,600 mm Width: 2,000 mm Approx. weight: 5,000 kg

Condition: ready for operation (used), Elgo CNC controlled machine, very easy and user-friendly max tube cap: dia 76 mm x 4 mm thickness max square tube: 70 x 70 mm max radius: 600 bending angle: 180° Standard tooling 3D Special tooling on request Kfodpfx Aajxpghqjnea Length: 1200 mm Width: 800 mm Height: 1300 mm

Condition: new, Model Name Kodpfx Aaogvqxtenjfa FALKEN R 1

Condition: as good as new (ex-display), Year of construction: 2025, Centre height: 181 mm Centre distance: 1000 mm Maximum grindable workpiece diameter: 360 mm Max load cantilevered: 1000 N (100 kg) Max load between centres: 3000 N (300 kg) Z-axis: Table swivel angle: 10° Table drive, hydraulic: 0–4 m/min X-axis: Cross slide travel: 80 mm Rapid traverse (hydraulic): 50 mm Coarse adjustment – air cushion: 280 mm Infeed drive by DC motor Rapid infeed speed: 48 mm/min/Ø Infeed cycle: Plunge grinding / Longitudinal grinding 4 preselectable speeds: mm/min/Ø: 0.01–48 4 preselectable infeed increments: mm: 0.001–0.1 Automatic shut-off during stop-grinding: 0–99 s or 0–99 strokes Kodpfjtqf Rzsx Aansfa Stepwise infeed: mm/Ø: 0.001 Grinding headstock universal, swivelling: 0–180° Grinding wheel (OD): D x width x bore: 500 x 100 x 127 mm or 203.2 mm Grinding wheel (face, option) D: 250 x 32 x 76.2 mm Grinding wheel (ID, option) D: 2–250 mm Drive power, external/face: 5.5 (7.5) kW Drive power, internal: 2.2 kW Peripheral speed, external: 35 (50) m/s Grinding wheel wear (OD): mm/Ø: 160 Guard width: 100 mm Grinding spindle diameter: 60 mm Internal spindle mounting: 80 (100) mm Workpiece headstock: Infinitely variable drive: MK 4, 1/min: 30–270 / 50–450 Workpiece spindle lockable Spindle mounting: MK 4/24 mm Spindle nose for flange attachment: MK 4, cylindrical Ø63H6 x 6 mm Headstock swivels on rotating part: 0–90° Tailstock: Quill mounting / Quill diameter: MK 4, 750 mm Quill stroke: 45 mm Quill force, N: 100–800 / 250–1400 adjustable Quill operation: manual (foot switch) Quill fine adjustment: ±40 μm Connections: Total machine connected load: 6.5–10 kW Grinding headstock: 5.5 (7.5) kW Workpiece headstock: 0.55 (1.1) kW Coolant filtration: 0.75–2.2 kW Lubrication pump – guideways: 0.1 kW Hydraulic pump: 1.5 kW Hydraulic tank: 80 l Pneumatics: 6 bar Comparable to: Weiss / EMAG / GP cylindrical grinders / Studer / Kellenberger / Schaudt / Tschudin / Tacchella / Dannobat

Condition: used, Year of construction: 1988, Manufacturer: Haacke type: UW II A-CNC year of construction: 1988

 only for step drills up to max. Ø 30mm cross adjustment: 250mm height adjustment: 250mm grinding length: 400mm weight: 1,4t footprint: 2,5 x 1,2 x 1,9mm Application: for grinding steps on step drills Kodog Tvmbepfx Aanjfa Accessories:

 Paper belt filter make LKK Foreground flap collet chuck Forkardt Overz /BR 50/ LH-Z 24394

Condition: used, Year of construction: 2013, grinding length 800 mm Kfsdpswd Tx Iofx Aanja grinding width 400 mm workpiece height 375 mm Control Siemens 840 D total power requirement 18 kW weight of the machine ca. 2,6 t Q U O T A T I O N We are pleased to offer you ex our stock, subject to prior sale, and error in technical data : GEIBEL & HOTZ CNC horizontal surface & profile grinding machine model FS 840 KT CNC year 2013 Serial no 38040513 _____ Grinding length max. (table movement 850mm) 800 mm Grinding width max. (cross movement 400mm) 450 mm Mounting height under new grinding wheel 375 mm Distance table – center of spindle min / max 140 – 525 mm Standard size of magnetic plate 800 x 400 mm Max. table load 700 kg Table speed 5 – 35.000 mm/min Cross-/Vertical quick feed 5 – 4.000 mm/min Grinding wheel measurements 300 x 50 x 76,2 mm (350 x 100 x 76,2) Cutting spped max. 45 m/s Grinding spindle-drive approx. 9 kW Total electrical load approx. 18 kW - 400 V - 50 cycles Weight approx. 2.600 kg Accessories / Special Features: • Machine is equipped with a simple to use but freely programmable SIEMENS CNC control model 840 D SolutionLine with additional GEIBEL&HOTZ grinding software. User friendly interface, supported by dialog and graphics, simple programming, also of complex grinding wheel profiling and easy connecting of all the usual grinding cycles. • electronic handwheel for 3 axis. • Table movement is actuated by ball screw drive (KT), which allows both very high and very low table speeds and is also ideal for profile grinding. • Cross feed (Z) and infeed (Y) effected by ball screw drive with incremental glass scale. • Diamond dressing device mounted on the left side of the table (also for profile dressing); additional driven diamond roller dressing device (table-mountable) with automatic dressing cycle, including compensation. • HOFMANN balancing device EasyBalancer EB3100 (with installed rpm & vibration sensor) • Unfortunately currently only a small magnet 110 x 200 mm available. • Separate band filter coolant filtration unit • Complete enclosure of the working area with electronically safeguarded sliding doors, separate switch cabinet, lamp for working area, various accessories, manuals, etc. Condition : very good, universal machine for all sorts of grinding tasks ! Please click here to view a video of the machine running : ! Delivery : immediately available, FCA Metzingen Payment : 100 % Net, after conclusion of contract, before loading We always have a large selection of surface grinders – CNC or conventional - available. Please let us know your requirements.

Condition: used, Distance between centers: 1000 mm Maximum external grinding diameter: 320 mm Grinding wheel dimensions (OD x ID x width): Ø500 x Ø127 x 80 mm Maximum internal grinding diameter: 200 mm Kedpoxxmcgsfx Aansfa Center height: 175 mm Control type (CNC/manual): CNC CNC brand: FANUC CNC model: 16GC Maximum grinding length: 1000 mm Maximum workpiece weight: 130 kg Main motor power: 7.5 kW / 2870 rpm Total power: 30 kW Internal grinding spindle power: 15 kW Max. workhead spindle speed: 30 - 750 rpm Voltage: 380 V / 50 Hz X-axis feed: 0.0001 – 5,000 mm/min Z-axis feed: 0.0001 – 10,000 mm/min Air pressure: 1.5 - 3 bar Coolant flow rate: 100 L/min Max. Z-axis travel: 1050 mm Max. X-axis travel: 275 mm Max. worktable swivel: 8.5º Workhead internal taper: M 5 Tailstock taper: M 3 Tailstock quill travel: 35 mm Dimensions (L x W x H): 3,687 mm x 2,000 mm x 2,090 mm Weight: 5,200 kg

Condition: ready for operation (used), chuck outer diameter: 3,200 mm, total height: 7,155 mm, controller model: Siemens 840D, empty load weight: 65,000 kg, Type: SKD 32B Siemens 840D CNC-besturing 2017 Tafeldiameter: 3200 mm Maximale zwenkhoek: 3500 mm Maximale belasting op tafel: 50 ton Hydrostatische tafel!! Vermogen op tafel: 120 kW Torsiesterkte: 132 Kn 2 variabele snelheidsversnellingsbak: ,8 80 tpm Verticale verplaatsing van de dwarsbalk: 2100 mm Maximale werkstukhoogte: 2550 mm 2 gereedschapskoppen op dwarsbalk CNC gestuurd - horizontale beweging van gereedschapskop nr. 1: 1400 mm - verticale beweging van gereedschapskop nr. 1: 1500 mm - horizontale beweging van gereedschapskop nr. 2: 1980 mm - verticale beweging van gereedschapskop nr. 2: 1350 mm - rotatiehoek van de gereedschapskop: -/+ 30° Max turningdia -- passage: 3500 mm Power on the spindle: 120 kW Number of speeds: 1 > rpm / > 80 rpm Power needed: 195 kVa Kfsdpfx Ajv Rwh Ieanea Long: 10045 mm Wide: 8120 mm

Condition: good (used), Year of construction: 2001, functionality: fully functional, machine/vehicle number: 2026, (Please tell us your offer price) Sale only within Europe, incl. Turkey Price without packaging; delivery condition: FCA (machine location) ===== Technical data see handout. All warranty rights are excluded. For the correctness of the technical data and year of construction, for the completeness of accessories and tool equipment, and for compliance with all safety and environmental protection requirements specified in the accident prevention regulations. No sale to private individuals. Sales only within Europe, incl. Turkey Price without packaging; Delivery condition: FCA (machine location) ===== Ksdpfoxrtarsx Aanofa Technical data please see handout in attachment. German text leading language. Without any guaranty and warranty, including completeness of tools & accessories as well as environmental and safety regulations. No private sales.

Condition: excellent (used), Year of construction: 1997, max. wheel diameter 820 mm gear width 300 mm max. module 8 min. module 0,5 clamping length 865 mm number of teeth 10 - 600 ical angle +/- 30 ° turning speeds 1100 - 2150 U/min grinding wheel diameter 280 - 400 mm grinding wheel width 84 /104 Kjdpswy H Ihsfx Aanefa workpiece weight max. 300 kg weight of the machine ca. 11,5 t dimensions of the machine ca. 6,0 x 4,8 x 2,9 m including Reishauer AF Filter, flanges, wheels,...

Condition: refurbished (used), Year of construction: 2025, Manufacturer: TSCHUDIN Machine type: SL 105U Year of construction: 2024 Kfsdpfx Ajd Adfusanea Workpiece headstock: MK6 Tailstock: MK4 Center height: 175 mm Center width: 1000 mm Grinding length: 1000 mm Control: Siemens 840D SL Space requirement of the machine: 4920x3400x2300

Condition: good (used), Year of construction: 2008, Machine is in good working condition. Parts shown by hand not come. Ksdpfxouwp Epj Aanefa Technical data are in documents .

Condition: used, Used machine Equipment and technical specifications: Kodpfx Aexdpmreanjfa - Design: double-sided grinding and polishing machine - Motor: asynchronous motor, 3-phase - Voltage: 380 V, 50 Hz - Motor power: approx. 2.2 kW - Speed: 2800 rpm - Grinding/Polishing wheels: left textile polishing wheel, right brush roller - Extraction connections: on both sides, Ø approx. 100 mm - Setup: heavy-duty cast iron stand, with transport wheels and mounting lugs - Machine weight: approx. 200 kg Location: Baden-Württemberg Availability: short notice

Condition: ready for operation (used), travel distance Z-axis: 600 mm, feed length X-axis: 800 mm, feed length Y-axis: 900 mm, controller manufacturer: Siemens 840D, controller model: Siemens 840D Solution Line, total height: 3,415 mm, total length: 4,500 mm, total width: 4,450 mm, empty load weight: 17,000 kg, chuck outer diameter: 700 mm, Type: Ultrix 800 RT De Ultrix 800 RT is een multifunctioneel bewerkingscentrum met 5 geïnterpoleerde assen en een bewegend portaal voor het snel frezen, draaien, slijpen, boren, tappen, afwerken, ontbramen en ruwen van complexe onderdelen. Bij gebruik voor draaien verticale draaibank: - draaibereik: 1100 mm - maximaal gewicht van het werkstuk: 700 kg - 40/30 kW op tafel - max. koppel op de tafel: 1500 Nm - maximale snelheid van de tafel: 1000 tpm !! - hydraulische klemming op tafel - gereedschapsconus voor draaien: KM63 - Gereedschapswisselaar met 150 posities en 24 gereedschapsposities voor het draaien Bij gebruik voor frezen, slijpen, boren, ... bewerkingscentrum: - X-as: 800 mm - Y-as: 900 mm - Z-as: 600 mm - A-as: -30° / 110° - C-as: continu - maximaal gewicht van het werkstuk: 700 kg - 55/40 kW op spindel - max. koppel op de spindel: 22 Nm - max 40.000 tpm - gereedschapsconus voor frezen: HSK-E40 - Gereedschapswisselaar met 150 posities en 126 gereedschapsposities voor frezen, slijpen en boren Lijst met op de machine gemonteerde opties: 1 - 40.000 tpm hogesnelheidsspindel 2 - tafel dia 700 mm met hydraulische klemming 3 - 150-positie gereedschapswisselaar 4 - spaantransportband 5 - koelsysteem met terugwinning 6 - Koelvloeistoftemperatuurregeling 7 - hoge druk koeling (40 tot 70 bar) door spindel 8 - rookafzuigsysteem 9 - chipverzamelbox 10 - Voorinstellingssysteem en gereedschapsintegriteit: laser- en mechanische taster voor meetgereedschappen 11 - Renishaw-meetkop Kfjdpfx Asxadmfoanoa Max turningdia -- passage: 1100 mm Power on the spindle: 40/30 kW Long: 4655 mm Wide: 5890 mm Turret: yes Qty Tools: 150 positions Coolant pump: yes

Condition: used, Year of construction: 1998, Year 1998 Control Fanuc In our opinion, the machines are in very good used condition Condition and can be viewed under power by appointment. Accesories: Kedpfx Aajxc Nyvenjfa - Suction - Felsomat loading system An accessory package can be purchased additionally. Accessories, tools and clamping devices shown are only included in the scope of delivery if this is noted in the additional information. Changes and errors in the technical data and information as well Subject to prior sale!

Condition: used, Year of construction: 2009, Grinding machines Travel distance X: 600 mm Travel distance Y :600 mm Travel distance Z: 335 mm Grinding width: 335 mm Kfedpew Eki Tjfx Aanea Grinding length: 800 mm Max. grinding plates: 300 mm Grinding spindle drive: 9,3 kW Speed adjustable: 4200 rpm Distance: table till middle of the spindle: 620 mm Table size: 600 mm Table longitudinal feed oscillation: 50 m/min Table longitudinal feed creep speed: 5 mm/min PA37K – CNC Profile Dressing Device (Diamond Dressing System)

Condition: used, Year of construction: 2017, functionality: unexamined, machine/vehicle number: 3480, total height: 2,789 mm, total length: 2,525 mm, total width: 2,400 mm, overall weight: 8,500 kg, Number of CNC axes (X/Y/Z/A/B/C): 5 to 6 Travel paths (X/Y/Z) [mm]: 630 / 345 / 430 Max. speed (X/Y/Z) [m/min]: 30 / 30 / 30 Swivel angle grinding spindle +/- (C axis): -225° to 70° Drive power grinding spindle [kW]: 11 / 11.5 / 21 Spindle speed range [min-1]: 0 to 8,000 / 18,000 / 30,000 Grinding wheel diameter [mm]: 250 Kfjdpfxsxqg Igs Aansa Abrasives: All types of abrasives Grinding length [mm]: 500 Workpiece length [mm]: 550 Workpiece cutting diameter [mm]: 260 Workpiece spindle taper: SK50 / HSK80/63/50 / Form A and E Control: Sinumerik One

Condition: ready for operation (used), total length: 900 mm, total width: 400 mm, total height: 1,100 mm, empty load weight: 140 kg, gasleiding: Ø50 x 3,91 mm stalen buis: Ø60 x 3 mm roestvrijstalen buis: Ø60 x 2 mm koper/alu buis: Ø64 x 4 mm massieve staaf: Ø35 mm massieve rechthoekige staaf: 60 x 10 mm vlakke staaf (hard): 60 x 16 mm platte staaf (gemakkelijk): 60 x 30 mm doosdoorsnede: 60 x 30 x 4 mm maximale straal: 200 mm buigsnelheid: 1,25 2,5 rpm Kjdpfx Asxlliroanjfa video klik hier Motor power: 1,5 kWt