Used Trumpf Tc 600 L for sale (398)

Condition: ready for operation (used), Year of construction: 2007, operating hours: 40,709 h, controller manufacturer: TRUMPF, travel distance X-axis: 3,000 mm, travel distance Y-axis: 1,500 mm, This 3-axis TRUMPF 3050 with liftmaster was manufactured in 2007, featuring a 6 kW laser, capable of cutting up to 20 mm, 15 mm in stainless steel, and 10 mm in aluminum. If you are looking to get high-quality cutting capabilities consider the TRUMPF 3050 machine we have for sale. Contact us for more information about this machine. • Mild Steel: 20 mm • Stainless Steel (SS): 15 mm Bcjdsx Imh Rjpfx Af Eeu • Aluminum (Alu): 10 mm

Condition: used, Year of construction: 2003, Standard configuration Siemens Operator panel front: 1P 6FC5203-0AF52-0AA0Siemens MCP 19", KEY, MPI Layout Laser 1P 6FC5203-0AF52-1AA0CPU: 1P 6FC5247-0AF08-2AA0 without refurbishment Bedpfxouqd D Eo Af Eecu

Condition: used, Year of construction: 2007, machine/vehicle number: A0240A0521, Working hours laser on: 50921 h Working hours beam on: 21717 h Laser power: 3200 Watt Working range laser: 4000 x 2000 x 115 mm Max. steel: 20 mm Max. stainless steel: 12 mm Max. aluminium: 8 mm Bodpfxjuqcw Rs Af Eocu Length: 11600 mm Width: 5300 mm Height: 2200 mm Machine weight: 16000 kg Electrical connected load: 73 kVA Standard configuration - Closed machine frame with integrated laser unit - Maintenance-free three-phase AC servo motors- Automatic pallet changer- Conveyor belt for small parts / slug- Work area lighting- Positioning laser diode- Oil spray device- AutoLas Plus- Hi-Las- PMS TRUMPF Laser- CO2 laser TLF 3200- Cooling unit- Radio-frequency - Radio-frequency excitation - Programmable cutting gas pressure - Laser power control - Logbook function Cutting head - Universal quickchange device for cutting head Control Unit - Siemens Sinumerik 840 D - 3,5" floppy drive - RJ45 network connection - Automatic shut down mechanism - Dignostic function - Maintenance logbook - Technology data Safety - Light barriers - Compact dust extractor - Multi chamber exhaust system - Beam delivery system Programming - Workshop programming ToPs 100 lite Extended machine accessories none Automation none

Condition: ready for operation (used), Trumpf test module for direct current, used, in good condition, 100% functional, scope of delivery as shown in the photos. Bcedpex Evaqefx Af Eou

Condition: ready for operation (used), Trumpf 1255448 Industrial PC / Industrie PC SW V4.2 HW Index A3 SN: 2918, used, in good condition, 100% fully functional, delivery as shown in photos Bcsdex Eu T Nepfx Af Eou

Condition: ready for operation (used), TRUMPF 200 MQ VIS focusing optic + Haas - Laser NBB 22-30-20-00 SN:9061842, used, normal signs of wear, 100% functional, delivery scope as shown in the photos. Bsdpfsx Eu Uysx Af Eocu

Condition: ready for operation (used), Trumpf / Hüttinger 1456168 control box Flow 36-48kW SN: 200128104 - 13.56MHz E, used, in good condition, 100% functional, scope of delivery as per photos Bjdpfx Aox Eu T Asf Eocu

Condition: ready for operation (used), Trumpf 19-01-11-11 Laser Module for Trumpf Laser HL1003D 11 with 11 and 11, used, in good condition, 100% functional, delivery contents as per photos. Bedpfx Afox Eu Uto Eecu

Condition: good (used), functionality: fully functional, Year of construction: 2003, Do you have a problem with the resonator on your TRUMPF laser cutting machine with 5 kW output? Then you’ve come to the right place! TruFlow 5000 / 5 kW resonator for TRUMPF laser cutting machines (L 3050 / L 4050 / L 6050 / TruLaser 5030 / 5040 / 5060) Power measurement during machine dismantling: 5,462 W (end of October 2025) (The machine still delivered 4,930 watts at the cutting head. The resonator is in very good condition in terms of output.) Leak test: 0.02 hPa Bcedoxzivbepfx Af Esu If you would like to replace your resonator or if you have issues with your turbine, feel free to contact us. All parts are available at short notice.

Condition: used, functionality: fully functional, Year of construction: 2005, We have various models of chiller units for TRUMPF laser cutting machines in stock! Bjdpfxowww Dnj Af Eocu Having issues with your chiller unit? Contact us! Chiller units for all common CO2 lasers in stock, whether 3.2 kW / 4 kW / 5 kW or 6 kW. All other spare parts are also available!

Condition: excellent (used), functionality: fully functional, Year of construction: 2018, operating hours: 19,000 h, sheet thickness steel (max.): 20 mm, sheet thickness aluminum (max.): 10 mm, travel distance X-axis: 4,000 mm, travel distance Y-axis: 2,000 mm, TRUMPF TruLaser 3040 – 5 kw (L32) Machine under TRUMPF service contract. TECHNICAL DATA: Bjdpfxovu D Dko Af Escu Make TRUMPF Type TruLaser 3040 – 4 kw Year of manufacture 2018 Working area 4,000 x 2,000 x 115 mm Control Siemens Sinumerik 840 D Laser power 5,000 watts Max. sheet thickness mild steel 20 mm Max. sheet thickness stainless steel 15 mm Max. sheet thickness aluminum 10 mm Operating hours NC on approx. 19,000 h (Jan. 2025) Beam approx. 9,500 h Detailed description follows!

Condition: excellent (used), functionality: fully functional, Year of construction: 2007, operating hours: 30,000 h, laser power: 3,200 W, sheet thickness steel (max.): 20 mm, travel distance X-axis: 3,000 mm, travel distance Y-axis: 1,500 mm, travel distance Z-axis: 115 mm, AVAILABLE FOR A SHORT TERM: TRUMPF TruLaser 3030 – 3.2 kW – Year 2007 with RotoLas! TECHNICAL DATA: Make: TRUMPF Type: TruLaser L 3030 – 3.2 kW Year of manufacture: 2007 Working area: 3,000 x 1,500 x 115 mm Control system: Siemens Sinumerik 840 D Laser power: 4,000 watts Max. sheet thickness mild steel: 20 mm Max. sheet thickness stainless steel: 12 mm Max. sheet thickness aluminum: 8 mm Operating hours: NC on 30,000 h (Oct. 2024) Machine regularly serviced by TRUMPF! Transmitter tube: new 2024 TASC laser control: new 2022 Driver stage: replaced 2018 Magnetic bearing electronics: new 2016 STANDARD EQUIPMENT: - Enclosed machine frame with integrated laser unit Laser unit: TLF 2000 CO2 laser with high-frequency excitation, maintenance-free turbo radial blower, Reflector telescope, cooling unit, logbook function - Automatic pallet changer - Longitudinal conveyor belt for small parts/waste - Drives: Maintenance-free three-phase servo motors - Cutting head quick-change device - Laser cutting head with 5" lens and laser cutting head with 7.5" lens - Programmable cutting gas pressure setting - APC capacitive height control and process control - Automatic focus position adjustment AutoLas Plus - Laser power control - Positioning laser diode - HI-LAS High-pressure cutting - Fast processing with SprintLas - ContourLas for producing small holes - PMS plasma sensors - Automatic sheet metal edge detection - Programmable power cycles - Microweld - Automatic shutdown - Workspace lighting - Sinumerik 840D control system: open PC-based control, easy operation, online help, integrated e-shop, diagnostic functions, maintenance logbook, technology data, teleservice - ToPs 100 lite workshop programming - Safety: multi-beam light barriers, fully encapsulated and ventilated beam guidance, monitoring system, multi-chamber extraction and compact dust collector, protective cabin - 3.5" floppy disk drive - TFT color screen - Electrical equipment: Voltage 400 V / 50 Hz - Paint finish: Standard RAL 9002/5010 Bcsdpfx Aju Afcbjf Esu EXTENDED EQUIPMENT: - TruFlow 3200 laser including lens monitoring sensors - PCS Process Control System - Preparation for LiftMaster - RotoLas pipe cutting system for cutting pipes and profiles

Condition: excellent (used), functionality: fully functional, Year of construction: 2009, operating hours: 39,500 h, laser power: 5,000 W, TRUMPF TruLaser 5030 – 5 kW Classic TECHNICAL DATA: Manufacturer: TRUMPF Model: TruLaser 5030 – 5 kW Classic Year of manufacture: 2009 Working area: 3,000 x 1,500 x 115 mm Control: Siemens Sinumerik 840 D Laser power: 5,000 Watt Max. sheet thickness (mild steel): 25 mm Max. sheet thickness (stainless steel): 20 mm Max. sheet thickness (aluminum): 12 mm Operating hours: 39,500 h STANDARD EQUIPMENT: - Enclosed machine frame with integrated laser unit - Laser unit: CO2 laser TruFlow 5000, high-frequency excited, maintenance-free turboradial blower, chiller, logbook function - Automatic pallet changer - Longitudinal conveyor belt for small parts/scrap - Drives: Gantry drive combined with linear direct drives - Quick-change cutting head system - PlasmaLine - Fast processing with SprintLas for all sheet thicknesses - ContourLine for production of small holes - Programmable power cycles Bcjdpfxsw Rytqe Af Esu - Microweld - Programmable cutting gas pressure setting - Laser cutting head with 5" lens and laser cutting head with 7.5" lens - Automatic sheet edge detection - ControlLine capacitive height control and process regulation - Positioning laser diode - Automatic focus position adjustment (FocusLine) - Automatic nozzle cleaning - PierceLine - NitroLine high-pressure cutting - Laser power control - Automatic shutdown - Work area lighting - SIN 840D control: PC-based open control, user-friendly operation, online help, diagnostic functions, maintenance logbook, technology data, teleservice - Shop floor programming - Safety: Multi-beam light barriers, fully enclosed beam guidance with nitrogen purging, monitoring system, multi-chamber extraction and compact dust collector, protective cabin - Network connection: RJ-45 network port via teleservice installation - 3.5" floppy disk drive - TFT color monitor - Electrical equipment for 400 V / 50 Hz three-phase current - Finish: Textured white RAL 9002 / gentian blue RAL 5010 ADDITIONAL EQUIPMENT: - Additional laser cutting head with 9-inch lens OTHER: - The machine underwent a technical overhaul in 2021

Condition: good (used), functionality: fully functional, Year of construction: 2013, laser power: 2,700 W, X working area max.: 2500 mm Y working area max.: 1250 mm Control system: Rexroth IndraMotion MTX (basic version) Laser power: 2700 Watt Standard Equipment Machine - Sturdy, easily accessible C-frame - Coordinate guide system for high-precision machining - Linear magazine with 23 tool stations and 2 clamps - Maintenance-free three-phase drive motors - Repositioning unit with programmable hold-down device - Foot pedal for clamp closing - Alignment pin (right inside) - Ball tables - 2 parts flaps 500 x 500 mm incl. sensor for parts ejection - Two good parts containers - NitroLine - Focus Line - FastLine - FlyLine Bsdpfxsx Aq Axo Af Ejcu - Slag cone detection - Ejector cylinder for laser parts TRUMPF Laser - TruFlow 2000 laser with LensLine and optimized standby mode - High-frequency excitation - Cooling unit - Laser control - Enclosed beam guidance - Fine filtration of compressed air for beam tube ventilation Cutting Head - Lens cutting head with 170 mm focal length - Universal cutting head quick-change system UTI with bus connection - ControlLine Punching Station - Electro-hydraulic punching head - Rotatable mono-tool holder - Tool length compensation - Programmable hold-down device with manually adjustable holding force - Stroke counter for punch and thread-forming - Punch spray lubrication - Punch slug extraction - Measurement of fill level in punching console - Level monitoring for thread-forming and tool lubrication Control - TRUMPF control based on Rexroth IndraMotion MTX - Operating panel with 17" touch screen - Integrated technology data - Teleservice via internet - Programmable cutting gas pressure - Automatic shutdown incl. wake-up mode - Program management - Production scheduling Data Transfer - Network connection RJ45 and USB interface Safety - CE marking - Two-beam light curtain - Monitoring system for gas pressure, temperature, and cooling water - Emergency stop - Protection against stray radiation - Compact extraction unit + Brush tables + Lowerable die + MultiTool function + Softpunch function + Marking function + Chip conveyor with tilting container + Roll technology functions: roll knurling, roll deburring, roll shearing, roll offsetting, roll bead forming, roll cutting + Die spray lubrication + Blow-off device for small parts + 1 pc. additional clamp + Smart Punch Monitoring (punch breakage monitoring) + Vibration-damped installation + Repositioning cylinder + Warping detection + Parts conveyor belt in punching area + Parts conveyor belt in laser area + GripMaster (2500x1250) + Scissor lift table + Scrap grid pallet + SheetMaster (2500x1250) (AK04) + Peeling system + Automatic clamp closing + HZP loading/unloading + TwinCarts loading station with toothed belt drive + TwinCarts unloading station with toothed belt drive

Condition: good (used), functionality: fully functional, Year of construction: 2011, laser power: 5,000 W, CNC Laser Cutting System TruLaser 5030 (L16) 5000 Watt X Working Area max.: 3000 mm Y Working Area max.: 1500 mm Z Working Area max.: 115 mm Control: Siemens Sinumerik 840D SL Laser Power: 5000 Watts Operating hours: 56,521 h Laser on time: 23,563 h Sheet thickness St. max.: 25 mm Sheet thickness Va. max.: 20 mm Sheet thickness Al. max.: 12 mm Standard equipment: - Enclosed machine frame with integrated laser unit - Motion unit for high-precision machining - Gantry drive in combination with linear direct drives - Enclosed beam guidance - Single cutting head strategy - Cooling unit KKW Riedel from 2003 - TFT color display - Longitudinal conveyor for small parts and waste Bcodpfxsx Ap Sfs Af Eju - Automatic pallet changer - Work area lighting - Positioning laser diode - Oil spray device - Piercline - FocusLine - NitroLine - PlasmaLine - CO2 laser TruFlow 5000 - Maintenance-free turbo radial blower - Cutting head with 250mm lens - Universal quick-change unit (UTI) with bus connection - ControlLine: Height control and sheet edge detection - SINUMERIK 840D - Automatic shutoff - ConturLine - FastLine - FlyLine - Microweld - USB interface - RJ-45 network connection - CE marking - Light barriers - Multi-chamber extraction system - Compact dedusting unit - High-speed cutting head 175mm focal length

Condition: good (used), Year of construction: 2023, operating hours: 5,001 h, functionality: fully functional, X working area max.: 3000 mm Y working area max.: 1500 mm Control: TRUMPF Control based on Rexroth IndraMotion MTX Machine: - Closed machine frame - Hybrid axis system - Linear magazine with 24 slots for clamps and tools - Hydraulic clamps (3 pieces) - Drives with maintenance-free three-phase motors - Repositioning with programmable hold-down device - Foot pedal for clamp closing - Parts chute on the right Punching Head: - Delta Drive - Rotatable mono-tool holder - Programmable hold-down position - Tool length compensation - Punch lubrication spray system - Punch slug extraction - Forming function - Stroke counter for punches Control: - TRUMPF Control based on Rexroth IndraMotion MTX - Touch panel with 19" TFT color display - Touchpoint - Programmable cutting gas pressure - Automatic shut-off - Remote support interface - Program management - Production planning Data Transmission: - USB interface - RJ-45 network interface - Central Link - Online Update Manager Safety: - CE marking and EC Machinery Directive - Dual-beam safety light curtain Extended Standard Equipment: - 1st positioning pin (inside right) + Brush tables + MultiTool + Thread forming with thread counter + Thread-former breakage monitoring + Lubricant level monitoring + Marking/rapid beading + Deburring and rolling technology + Adaptive stroke calibration + Die lubrication spray system + Smart Punch Monitoring + Parts flap on the left + Parts conveyor belt for parts flap left + Collection tray for parts conveyor left + Sensor for parts chute + Parts conveyor for parts chute right + Additional clamp + 4x individually openable clamps + 4x height-adjustable clamps + Automatic clamp closing loading sensor system + Optical loading sensor + Automatic repositioning movement to compensate for loading tolerance + Repositioning device for DeltaDrive + Vibration-dampened installation + Chip conveyor with tilting bin + Machine status light + Warpage detection + Wireless Operation Point Bcedpoxxbwxofx Af Eou SheetMaster Compact 3000 x 1500 (AK05): - Loading station with spreading magnet for sheet separation - Suction frame - Vacuum sensors - Double sheet detection - Unloading cart for residual grids and microjoint sheets - Second operator station for loading and unloading + Compact setup for light grid and reference point system + Peeling system SortMaster Compact: - Machine-integrated automated small part removal - Suction frame for unloading good parts up to 600 x 400 mm (X x Y) - 2 suction bars (each suction cup individually controllable) - Unloading area 600 x 800 mm - Vacuum sensors for the suction circuits + X-axis extension - Extension of the unloading area to 1200 x 800 mm

Condition: ready for operation (used), functionality: fully functional, Year of construction: 2006, operating hours: 59,480 h, laser power: 3,200 W, travel distance X-axis: 3,000 mm, travel distance Y-axis: 1,500 mm, travel distance Z-axis: 600 mm, swivel angle B-axis (max.): 100 °, swivel angle C-axis (max.): 360 °, No reserve price – guaranteed sale to the highest bidder! Predecessor model of the well-known TruLaser Cell series TECHNICAL DETAILS Category: 5-axis 3D laser cutting system Condition: Fully serviced (twice annually by Trumpf UK) Last service: January 2019 New vacuum pump installed: 28/05/2019 Working Area X-axis: 3,000 mm Y-axis: 1,500 mm Z-axis: 600 mm B-axis (rotational axis): +100° C-axis (rotational axis): n x 360° Laser Source Model: TRUMPF TLF 3200 Turbo Laser power: 3.2 kW Pilot laser: Present (for programming support) Control & Software CNC control: Siemens 840D with 3.5" floppy disk drive Network connectivity: Available (including analog modem for remote maintenance) Software: ToPs 100 with nesting module & IGES translator + ToPs 800 with fixture design & 3D IGES translator MACHINE DETAILS Beam on: 14,922 h Laser on: 59,480 h Dimensions: 3.0 x 1.5 x 0.6 m EQUIPMENT - Logbook function for laser power monitoring - Power supply cabinets - Closed-loop water cooling with air circuit - 5” high-pressure cutting optics - Setup device - Class 1 laser safety housing with manual sliding door - Extraction unit with particle filter (2,000 m³/h) - Stationary worktable Bcodoxv Slhjpfx Af Eeu

Condition: good (used), functionality: fully functional, Year of construction: 2008, machine/vehicle number: A0230A1932, control type: NC control, degree of automation: manual, actuation type: mechanical, controller manufacturer: Siemens, controller model: Siemens 840D, laser type: CO₂ laser, laser power: 5,000 W, sheet thickness steel (max.): 25 mm, sheet thickness stainless steel (max.): 20 mm, sheet thickness aluminum (max.): 12 mm, working length: 3,000 mm, working width: 1,500 mm, year of last overhaul: 2025, Equipment: centralized greasing system, chip conveyor, cooling unit, documentation/manual, dust extraction, emergency stop, fume extraction, safety light barrier, Comprehensive accessories and spare parts – bellows and other wear parts renewed in 2025!! On-site inspection possible or even recommended!! Bsdpfx Afsycwuvo Eecu

Condition: used, functionality: fully functional, Year of construction: 2000, laser source manufacturer: Trumpf, laser source model: TLF 3000 turbo, laser power: 3,000 W, power: 3 kW (4.08 HP), input voltage: 400 V, input frequency: 50 Hz, type of input current: AC, compressed air connection: 6 bar, Trumpf Maschinen Grüsch AG, laser cutting machine, TRUMATIC LC3030 Model: LC3030 Bodpjyazrtofx Af Eecu Series: Trumatic Year of manufacture: 2000 General information: Input voltage: 400V AC Frequency: 50Hz Connected load: 73kVA Control voltage: 24V DC Required protection: 3x125A Laser power: 3,000W Compressed air connection: 6 bar Nitrogen connection (N2): 30 bar Oxygen connection (O2): 20 bar Max. component size: 3,000 x 1,500 x 20 mm Accessories: Liftmaster Loading and unloading stations

Condition: ready for operation (used), functionality: fully functional, Year of construction: 2013, machine/vehicle number: S2321M0007, laser power: 400 W, This TruLaser Cell 3000 is used to cut parts out of coil, in thin sheet-thicknesses. It has an automatic feed of the material in the lasercel. The machine is visible in production. Bjdex Hiy Hepfx Af Eocu

Condition: ready for operation (used), Trumpf 19-01-11-11 Laser Module for Trumpf Laser HL1003D 11 with 11 and 11, used, in good condition, 100% functional, delivery contents as per photos. Bcedpfx Afjx Dxqyo Eju

Condition: ready for operation (used), Trumpf 19-01-11-11 laser module from Trumpf Laser HL1003D 11 with 11 and 11, used, in good condition, 100% functional, delivery as per photos. Bjdox Dxqtjpfx Af Eocu

Condition: used, functionality: unexamined, Year of construction: 2008, control type: CNC control, degree of automation: automatic, controller manufacturer: Trumpf, laser type: CO₂ laser, laser source manufacturer: Trumpf, laser power: 5,000 W, Auction: Plant Closure Roschmann, Gersthofen (Augsburg) Bid now – Sale to the highest bidder. Lot 2910012: Complete industrial-grade laser cutting system, consisting of a TRUMPF TruLaser 5040 with 5 kW TruFlow CO₂ laser source, a Handte MF-L filtration unit, and a Schmalz vacuum lifting crane. Suitable for high-performance sheet metal cutting of steel, stainless steel, and non-ferrous metals. Machine: TRUMPF TruLaser 5040 Laser power: 5,000 W (CO₂) Year of manufacture: 2008 Power supply: 400 V / 50 Hz, 105 kVA Fuses: 3 × 160 A Control voltage: 24 V DC Compressed air: 7–10 bar N₂ connection: 30 bar Bcedpfx Asx N Nkwef Eeu O₂ connection: 20 bar Laser source: TruFlow 5000, manufactured on 15/05/2008 Filtration unit: Handte MF-L 50/10/1, 2,500 m³/h, 355 daPa, 50 m² filter area, year of manufacture 2008 Vacuum crane: Schmalz vacuum handling system Control: CNC with integrated operator panel Condition: Regularly serviced, overhauled in 2025 Operating hours: 50,187 (as of 02/2025)

Condition: used, functionality: fully functional, 1. BALL RECIRCULATING UNIT KUVE20-B-1947 PART NO.: 386954 1 PC. Machine: T3030 L20 COUNTRY OF ORIGIN: FR 2. WATER MANIFOLD COMPLETE PART NO.: 1996899 1 SET Machine: T3030 L20 3. WELDING HEAD WS OPTICS 1 SET Machine: T3030 L20 4. CUTTING HEAD LENS 250 D40 – 17616 PART NO.: 1497234 1 PC. Machine: T3030 L20 COUNTRY OF ORIGIN: DE 5. (R)GRID VOLTAGE UNIT PART NO.: 0983675 1 PC. Machine: T3030 L20 6. BELLOWS Y-AXIS 93614-102-40 PART NO.: 0141394 1 PC. Machine: T3030 L20 7. EXPANSION VALVE TGEN 25TR MOP70 R134a PART NO.: 1627195 1 PC. Machine: 3030 6kW Bsdpfx Afox Uzbls Eocu 8. BELLOWS X-AXIS 1854032 PART NO.: 606083 1 PC. Machine: T3030 L20 COUNTRY OF ORIGIN: IT 9. TRIODE UP TO 4KW RS3021CJ PART NO.: 903994 1 PC. Machine: T3030 BRAND: THALES 10. FILTERS 8 PCS. Machine: T3030 11. BELLOWS Y-AXIS PART NO.: 1226193 1 PC. Machine: T3030 5kW 12. DISK BELLOWS Y-AXIS PART NO.: 1353514 1 PC. Machine: T3030 5kW 13. BOX BELLOWS PART NO.: 0978079 1 PC. Machine: T3030 5kW

Year of construction: 2003, condition: good (used), Used quality Trumpf 5kw cnc laser 4metre x 2metre cutting bed Its just been serviced by Trumpf and outputting the same power as new. Very low hours for its age, very good condition, used intermittently on one shift and available to see in operation by appointment: Make – Trumpf Model – Trumatic L 4050 Laser type – TLF 5000TM / 5kw / 5000watts Year of manufacture – 2003 – commissioned 2004 Size – 4metre x 2 metre Features – Rotolas tube cutting facility (examples of parts just processed per photographs) Hours – Laser turned on 33861 – Beam on 11480 Bcodpfx Aehcw Nzef Eju Fully serviced with Trumpf uk