EO-Performance

Condition: good (used), functionality: fully functional, Grinding length: 1000 mm Podpfezqr Huox Am Tepw Weight: 5,500 kg

Condition: used, Year of construction: 2001, Control Fanuc Top height above table 150 mm max. grinding diameter 300 mm centre distance 600 mm max. grinding length 600 mm max. workpiece weight 150 kg Grinding wheel angle 0 ° Overall size 3.100 x 2.520 x 2.100 mm In our assessment, the machine is in good used condition and can be inspected under power by appointment. The machine was used for grinding eccentric shafts and is equipped with a Marposs gauging system. Psdpjzp Rzbjfx Am Tjpw Accessories, tools, and work-holding devices shown are included in the scope of delivery only if specified in the additional information. Subject to change, errors in technical data and specifications, and prior sale.

Condition: used, Year of construction: 2020, operating hours: 21,398 h, machine/vehicle number: IntNr231185, EMAG WEISS W11 CNC SL650 – Universal Cylindrical Grinding Machine – Year of Construction: 2020 For sale is a used EMAG WEISS W11 CNC SL650 – a high-performance universal cylindrical grinding machine with CNC control. This machine is ideally suited for demanding grinding operations on individual parts, prototypes, and small to medium production runs. Machine Specifications Manufacturer: EMAG WEISS Type: W11-CNC SL650 Year of Construction: 2020 Operating Hours: Approx. 8,850 spindle hours / approx. 22,000 power-on hours Condition: Used, well-maintained, ready for immediate operation Technical Data Control: CNC-controlled (e.g., Heidenhain / Siemens / Fanuc – depending on the configuration) Max. Grinding Length: 650 mm (between centers) Center Height: Approx. 200 mm External Grinding Diameter: Up to approx. 390 mm Max. Workpiece Weight (overhanging): Approx. 100 kg (MK4) Ppedszp Idtspfx Am Tjw Max. Workpiece Weight (between centers): Approx. 250 kg X-Axis Traverse: Approx. 380 mm Z-Axis Traverse: Approx. 1,150 mm Grinding Wheel Diameter: 400 – 500 mm depending on equipment Rated Power: 9 – 11 kW (approx. 12 – 15 hp) Peripheral Speed: 20 – 50 m/s Equipment and Performance Features CNC touchscreen operation with Windows-based interface – user-friendly programming via dialogue or DIN/ISO (optional) Two-in-one concept: The machine can be operated both conventionally and CNC-controlled. High-precision linear and ball screw guides for high accuracy Direct measuring system (glass scales) (optional on many machines) Automatic dressing of the grinding wheel with compensation Crash control & gap monitoring for machine and process safety Coolant system, emulsion separator, and chip conveyor available (depending on equipment) Preparation for automation / robot interface possible The machine can be inspected in operation by appointment. Subject to changes and errors in technical data and specifications as well as prior sale!

Condition: used, functionality: fully functional, Universal cylindrical grinding machine Ziersch & Baltrusch URS 750 (year of manufacture 1984) from a company liquidation. Conventional external and internal cylindrical grinding machine of German manufacture with a center distance of 750 mm – for grinding shafts, pins, and cylindrical mating surfaces. EQUIPMENT & TECHNOLOGY - Center distance: 750 mm Psdpfjzphf Rsx Am Tepw - External and internal cylindrical grinding - Swiveling grinding head – conical grinding also possible - Solid bed design, stable guides, high runout accuracy - Digital readout (DRO, Fagor) available – see photos Ziersch & Baltrusch was a renowned West German manufacturer in the grinding machine segment. Well-maintained machines of this series are still in reliable use today. APPLICATION Ideal for job production, repair workshops, and general machine manufacturing. CONDITION Used, ready for operation. Located near Nuremberg, viewing by appointment. Sold as is, no warranty. ACCESSORIES (according to photos) - 2-axis digital readout (DRO, manufacturer Fagor) - Tailstock and centers (grinding between centers) - Swiveling workpiece spindle head (conical grinding) - Steady rests - Grinding wheels Price on request. We will be happy to advise you – competent advice and nationwide service.

Condition: ready for operation (used), functionality: fully functional, The Studer S30-12 CNC is a precision cylindrical external grinding machine from Fritz Studer AG. Brand: Studer Type: S30-12CNC Serial number: 1248.74 Dimensions: L3250mm Ppodpfxjzn Nqro Am Tsw Dimensions: W2000mm Dimensions: H1950mm Wheel speed: 30 m/s

Condition: used, Year of construction: 1990, External/Internal Cylindrical Grinding TARDUGNO RIBON type MODULE 2A Between points: 1000 mm Centre height: 180 mm Workpiece holder spindle CM4 Maxi grinding diameter: Ø 360 mm Ppjdpfozn Ib Nex Am Tow Workpiece holder rotation: from 35 to 310 RPM Year of construction: 1990 Tilting table - 9° / + 6° Grinding wheel dimensions: Ø 406 mm x thickness 60 mm Scale on table X Spindle speed: 1500 - 1730 RPM Grindstone motor: 5,5 CV Hydraulic tailstock CM3 Auto wheel advance Internal grinding spindle: Max speed 20000 RPM Maxi boring: from 14 to 75 mm Lubricant tank+ paper filter Diamond system Tilting grindstone holder trolley Supplied with grinding wheels + steadies Voltage: 380 V Dimensions (L x W x H): 3800 x 2000 x 2200 mm Weight: approx 3,2 T

Condition: good (used), Nordier Cylindrical Grinding Machine. Psdpfxjzndvcs Am Topw

Condition: used, Year of construction: 1988, grinding diameter 350 mm Podpfjzmy Thsx Am Tepw grinding length 1000 mm centre height 175 mm Control Kelco weight of the machine ca. 4 t

Condition: used, Year of construction: 2010, TACCHELLA Elektra Evo Plus 1018 Grinding diameter: 350 mm Grinding length: 1000 mm Center height: 180 mm Control: Fanuc Grinding wheel width: 80 (100) mm Grinding wheel diameter: 450 mm Psdpfx Aezmtblem Tepw Grinding wheel motor power: 7.5 kW

Condition: good (used), Description Grinding diameter: 350 mm Grinding length: 1000 mm Psdjzmmthepfx Am Tepw Center height: 180 mm Control: Fanuc 180-T Grinding wheel width: 80 (100) mm Grinding wheel diameter: 450 mm Grinding wheel motor power: 7.5 kW Table speed: continuous 10 m/min Swiveling grinding wheel head: ° Speed range (workpiece spindle): 10 - 800 rpm Swiveling workpiece head: 0 - 15° Maximum workpiece weight: 120 kg Tailstock mounting taper: MK 4 Tailstock quill travel: 35 mm Operating voltage: 400 V Total power consumption: 18 kW Machine weight (approx.): 6.5 t Dimensions (approx.): 3.75 x 2.25 x 1.80 m - Factory number: 6769 - Universal external grinding machine with attachment for internal grinding - B-axis controlled for automatic swiveling of the grinding wheel head

Condition: like new (used), Year of construction: 2019, functionality: fully functional, CNC cylindrical grinding machine Lizzini IG-FL Year of manufacture: 2019 Condition: Absolutely like new Control system: Siemens 840D sl Equipment: - 2 external grinding wheels - 1 internal grinding attachment with C-axis and fully controlled B-axis Distance between centers: 1000 mm Distance between centers (vertical): 200 mm Ppsdpfx Amszmhumj Tow

Condition: ready for operation (used), functionality: fully functional, center height in crank: 125 mm, center height: 125 mm, grinding length: 600 mm, Distance between centers: 600 mm Height of centers (standard): 125 mm Speeds of the grinding spindle: 1500 / 1700 / 2200 / 3600 Grinding head swivels: 360° Psdpfx Amozmhtve Tjpw Transverse travel of the grinding head: 285 mm

Condition: used, Year of construction: 1980, Round grinding machine (internal and external) KELLENBERGER 1000 U-175, serial no. 32460-2247, year of manufacture 1980, max. grinding length 1,000 mm, max. diameter 350 mm. Ppedpfx Aszlpr Dsm Tsw

Condition: used, External/Internal Cylindrical Grinding GENDRON RU 28.100 Between points: 1000 mm Maxi grinding diameter: Ø 290 mm Tool holder rotation: from 70 to 370 RPM 4-jaws Ø 200 mm chuck Grinding wheel: Ø 300 mm Auto pass plug Swivel table External hydraulic group External lulbricant tank Ppodezk Dayepfx Am Tew Voltage: 380 V Dimensions (L x W x H): 3000 x 1900 x 2000 mm Weight: approx 3 T

Condition: used, External/Internal Cylindrical Grinding JONES-SHIPMAN type 1310 Capacity: Ø 200 x 450 mm (8'' x 18'') Tilted table Grinding wheel: Ø 300 mm x thickness 25 mm x bore Ø 125 mm Drive wheel speed: 1750 and 2300 RPM Rotary grindstone holder support Supplied without internal grinding spindle Equipped with 1 lubricant tank Voltage : 380 V Ppedpfszk Damsx Am Tsw Length: 1800 mm Depth: 1600 mm Total height: 1900 mm Weight: approx 2 T

Condition: used, grinding diameter 450 mm grinding length 1000 mm centre height 225 mm Fotos von bereits gelieferten Maschinen. Mechanische Überholung: -komplette Maschine nach Kellenberger Messprotokoll überholt -Neue servicefreundliche Kabine -Neulackierung Elektrische Überholung: -FANUC Steuerung mit BLUE-SOLUTION -Neu aufgebauter Schaltschrank -Neue Antriebstechnik -Austausch sämtlicher elektrischer Leitungen Berus Druckschalter etc. -Neue Absolut-Glasmaßstäbe in x- und z -Neuer Absolut Drehgeber (Bei-B-Achse) Fotos von bereits gelieferter Maschine mit anderen Optionen. Schleikopfvariante UR/RS: Podszkvucopfx Am Tepw -Schleifscheibenanordnung für Aussen -und für Schrägeinstichschleifen hintereinander! -Dadurch jeweils 400mm Scheibendurchmesser! -Dadurch wesentlich geringere Kollisionsgefahr -Einfacheres programmieren -Schleifscheibenausrüstung jeweils 400x63x127mm -Einrichtung zum Betrieb einer HF-Spindel -Spindel optional gegen Aufpreis -B-Achse CNC gesteuert zum Aussen-Plan- und Innenschleifen in einer Aufspannung. Schwenkbereich +10°/-270° -C-Achse zum Polygonschleifen -Unterteil fest -Schleifkopfmotor 10,0 KW -Reitstock -Marposs Messsystem zur Schleifscheibenvermessung. -Längspositionierung Marposs

Condition: good (used), Year of construction: 1989, functionality: fully functional, Turning diameter on the table: 300 mm Distance between centers: 1,000 mm Max. external grinding diameter with 355 mm wheel: 270 mm Max. external grinding diameter with 405 mm wheel: 220 mm Max. external grinding diameter with 510 mm wheel: 115 mm Max. workpiece weight between centers: 130 kg Grinding headstock Swivel angle left/right: +/- 30° Standard wheel dimensions: 355 x 152.4 mm Special wheel dimensions: 405 x 152.4 mm Standard wheel width: 25-50 mm Special wheel width: 100 mm Handwheel feed rate per division: 0.0025 mm Automatic infeed speed: 0.02-1.5 mm/min Automatic feed speed during surface grinding: 0.001-0.1 mm/min Workpiece headstock Swivel angle: 120° Spindle speed, 50 Hz: 24-302 rpm Spindle speed, 60 Hz: 29-363 rpm Psdpjzi Dvxjfx Am Tspw Taper of the center: MK 4

Condition: used, Year of construction: 2003, functionality: fully functional, Control system: Siemens Sinumerik 840D Includes: Grinding media preparation, hydraulic unit, and portal loading system for loading and unloading the machine. Technical data: Center distance: 600 mm, Center height: 180 mm Maximum grinding diameter: 355 mm Maximum workpiece weight: 150 kg Maximum Z-axis speed: 11 m/min Minimum Z-axis speed: 0.01 m/min Maximum X-axis speed: 7.5 m/min Minimum X-axis speed: 0.01 m/min External cylindrical grinding spindle: Grinding wheel standard (outer diameter x width x inner diameter): 600 x 80 x 304.8 mm Grinding wheel peripheral speed: 5 - 50 m/s Power consumption of grinding spindle motor: 11 kW Workpiece spindle: Taper bore of workpiece spindle: MK 5 Power consumption: 2.7 kW Tailstock: Taper bore of center: MK 4 Coolant tank: 2000 liters, Lubricating oil: 30 liters, Hydraulic oil: 60 liters Operating voltage: 400 volts, 3 phases Pjdpfx Amezh Ux Io Topw Mains frequency: 50 Hz Total machine weight: approx. 5800 kg Operating sound pressure level: 70 dB (A)

Condition: used, Year of construction: 2003, functionality: fully functional, Siemens Sinumerik 840D control system includes: grinding media preparation, hydraulic unit, and portal loading system for loading and unloading the machine Technical data: Center distance: 600 mm, center height: 180 mm maximum grinding diameter: 355 mm maximum workpiece weight: 150 kg maximum Z-axis speed: 11 m/min minimum Z-axis speed: 0.01 m/min maximum X-axis speed: 7.5 m/min minimum X-axis speed: 0.01 m/min Psdpfx Amjzh Uwqs Tepw External cylindrical grinding spindle: Grinding wheel standard (outer diameter x width x inner diameter): 600 x 80 x 304.8 mm Grinding wheel peripheral speed: 5 - 50 m/s Power consumption of grinding spindle motor: 11 kW Workpiece spindle: Taper bore of workpiece spindle stock: MK 5 Power consumption: 2.7 kW Tailstock: Taper bore of center: MK 4 Coolant tank: 2000 liters, lubricating oil: 30 liters, hydraulic oil: 60 liters Operating voltage: 400 volts, 3 phases Mains frequency: 50 Hz Total machine weight: approx. 5800 kg Operating sound pressure level: 70 dB (A)

Condition: used, Year of construction: 2001, functionality: fully functional, Control system: Siemens Sinumerik 840D Includes: Grinding media preparation, hydraulic unit, and portal loading system for loading and unloading the machine. Technical data: Center distance: 600 mm, Center height: 180 mm Maximum grinding diameter: 355 mm Maximum workpiece weight: 150 kg Maximum Z-axis speed: 11 m/min Minimum Z-axis speed: 0.01 m/min Maximum X-axis speed: 7.5 m/min Minimum X-axis speed: 0.01 m/min External cylindrical grinding spindle: Grinding wheel standard (outer diameter x width x inner diameter): 600 x 80 x 304.8 mm Grinding wheel peripheral speed: 5 - 50 m/s Power consumption of grinding spindle motor: 11 kW Workpiece spindle: Taper bore of workpiece spindle: MK 5 Power consumption: 2.7 kW Tailstock: Ppjdszh Uvtjpfx Am Tow Taper bore of center: MK 4 Coolant tank: 2000 liters, Lubricating oil: 30 liters, Hydraulic oil: 60 liters Operating voltage: 400 volts, 3 phases Mains frequency: 50 Hz Total machine weight: approx. 5800 kg Operating sound pressure level: 70 dB (A)

Condition: used, Year of construction: 2003, functionality: fully functional, Siemens Sinumerik 840D control system includes: grinding media preparation, hydraulic unit, and portal loading system for loading and unloading the machine Technical data: Center distance: 600 mm, center height: 180 mm Pedszh Uvaepfx Am Topw maximum grinding diameter: 355 mm maximum workpiece weight: 150 kg maximum Z-axis speed: 11 m/min minimum Z-axis speed: 0.01 m/min maximum X-axis speed: 7.5 m/min minimum X-axis speed: 0.01 m/min External cylindrical grinding spindle: Grinding wheel standard (outer diameter x width x inner diameter): 600 x 80 x 304.8 mm Grinding wheel peripheral speed: 5 - 50 m/s Power consumption of grinding spindle motor: 11 kW Workpiece spindle: Taper bore of workpiece spindle stock: MK 5 Power consumption: 2.7 kW Tailstock: Taper bore of center: MK 4 Coolant tank: 2000 liters, lubricating oil: 30 liters, hydraulic oil: 60 liters Operating voltage: 400 volts, 3 phases Mains frequency: 50 Hz Total machine weight: approx. 5800 kg Operating sound pressure level: 70 dB (A)

Condition: excellent (used), KELLENBERGER PRECISION UNIVERSAL CYLINDRICAL GRINDING MACHINE TYPE: 600 U YEAR OF MANUFACTURE: 2003 PARTIAL OVERHAUL: 2026 (Technical data see attached documents) Center height: 175 mm (without height adjustment) Grinding length: 600 mm Equipment: - Standard accessories - Internal grinding device for D: 80 mm max. incl. coolant supply through the workpiece spindle - Grinding wheel equipment left for D: 400 x 50 x 127 mm (standard) - Grinding wheel equipment right for D: 300 x 40 x 127 - Grinding wheel flange for wheels D: 400 x 50 x 127 mm (left) and D: 300 x 40 x 127 (right), balancing weights outside (3 pieces left, 2 pieces right) - Variable spindle drive with Danfoss frequency converter - Balancing device for dynamic balancing, type ELASO MANOBALANCE 750/EB 2000 - RENAUD internal grinding spindle type REN 828 (grease-lubricated with compressed air lock) - Various internal grinding mandrels for REN 828 – 1235, 1645, 2060, 2575 (4 pieces) - Various chucks HJNZ 28 for HJN 828 with 2 collets D: 3 mm and D: 6 mm - Tailstock standard MK 5 with adapter flange DIN 55027 size 5” Bore D: 38.2 mm (standard) Ppjdezhma Dopfx Am Tew - Sine bar on the tailstock - Tailstock with manual retraction for quill travel - Micrometer adjustment on the tailstock - Pneumatic relief of the tailstock - FORKARDT planetary three-jaw chuck D: 200 mm - REISHAUER wedge-bar three-jaw chuck D: 160 mm - Permanent magnet chuck D: 200 mm - Collet chuck for Schaublin B32 - Set of 59 collets Schaublin B32, D: 1.0 – 30.0 mm, graduation 0.5 mm - Set of 8 workpiece supports incl. holder - Three-jaw steady rest, 175 mm, foldable, D: 3-120 mm - Swiveling dressing tool for dressing during external, surface or internal grinding - Side and angled dressing tool for side and angled dressing of the grinding wheels - Dial indicator stop for table swiveling with dial indicator 1/100 mm - Dial indicator stop for table longitudinal movement with dial indicator 1/100 mm - Dressing stop for internal grinding - HEIDENHAIN Digital length measuring system for the X and Z axes - STREULI paper band filter SPB 3, 90 l/min at 0.26 bar, tank volume 240 l - WALDMANN machine lamp - Set of vibration-damping pads - Three-color paint finish (light gray RAL 7035/blue RAL 5012/dark gray RAL 7016) - New acceptance test report according to KELLENBERGER standard - CE conformity - Documentation Condition: very good, machine geometrically and mechanically overhauled (see geometry report)

Condition: used, Year of construction: 2017, controller manufacturer: Siemens, controller model: 840 Dsl, _____ Description: Year of manuf. : 2017 Control : Siemens 840 Dsl Grinding length : 1000 mm In General: Year of manufacture:2017 Control system:Siemens 840 Dsl Centre height:180 mm Centre distance:1,000 mm Maximum workpiece weight:150 kg X-Axis: Technology:Electromechanical Transverse speed:0.001 – 8,000 mm/min Measuring system:Direct, 0.0005 mm (glass scale) Guideway:Hydrostatic Z-Axis: Technology:Electromechanical Table speed:0.01 – 12,000 mm/min Measuring system:Direct, 0.0005 mm (glass scale) B-Axis: Technology:Continuously swivelling axis Ppjdpfozhdybox Am Tsw Resolution:0.001° Clamping:Hydropneumatic Workpiece spindle: Power:2.0 kW Speed:0–600 rpm Chuck:MK 5 and KK 5 C-axis:0.001° Grinding spindle: Disc configuration:left/right Power:9 kW Speed:1,400 rpm Internal grinding spindle: Power:2.2 kW Speed:60,000 rpm Tail stock: Quill stroke:40 mm Mounting:MK 4 Quill retraction:Hydraulic Cylinder fine adjustment:Yes Equipment: Coolant supply:Coolant system with filter Emulsion mist separator:Mechanical Grinding wheel dresser:Diamond dressing tile Technology option I:Cone grinding Technology option II:Out-of-round grinding Balancing system:Automatic Grinding detection:Via structure-borne sound Workpiece measurement:Linear encoder Accessories:Various flanges, discs and mandrels

Condition: good (used), Year of construction: 2021, operating hours: 5,500 h, grinding length: 600 mm, grinding diameter: 440 mm, feed length X-axis: 325 mm, feed length Z-axis: 750 mm, Control system, serial number and main data o Control system: SIEMENS, Type 840 D SL o Operating hours recorded: 5,475 Travel ranges o X-axis travel: 325 mm o Z-axis travel: 750 mm Psdpfx Amozgdtle Tspw Axis speeds o X and Z axes max.: 15,000 mm/min o X and Z axes min.: 0.01 mm/min Working area o Max. grinding length: 600 mm o Max. grinding diameter: 440 mm o Min. grinding diameter: 10 mm Performance data o Grinding spindle: 1 tool for external cylindrical grinding o Tool dimensions: Ø 610 x 160 x 304.8 mm o Cutting speed: 60 m/s o Power: 15 kW Workpiece spindle o Speed range: 30 - 5,000 min⁻¹ o Taper: 5 Morse Tailstock o Design: pneumatic o Max. quill stroke: 80 mm o Taper: 5 Morse Connection values o 400 V / 50 Hz / 71 A / 43 kW Automation / Peripherals • Handling robot, YASKAWA, Type YR-1-06VXH12-A00, year of manufacture 2022, serial number 6V2272528290001 • Automation system / workpiece storage, EGS AUTOMATION DANOBAT, Type CG600-BL1, year of manufacture 2023, serial number 190605-6, 2-position • Filter, 3FS, Type M1600, No. 565209, year of manufacture 2021, weight 85 kg • Oil band filter, MICROFILTER, Type EASYBAND 150, serial number 0202, year of manufacture 2021 • Pump, REXROTH, Type HM-46

Condition: good (used), Year of construction: 2022, operating hours: 7,400 h, machine/vehicle number: 100644, grinding length: 600 mm, workpiece length between centers: 600 mm, feed length X-axis: 650 mm, feed length Z-axis: 1,000 mm, overall weight: 10,000 kg, Control, monitoring, and operating data o NC control: SIEMENS, Type 840 D SL o Year of manufacture: 2022 o Serial number: 100644 o Recorded operating hours: 7,315 o Monitoring system: MARPOSS, Type P7 Travel ranges o X-axis: 650 mm o Z-axis: 1,000 mm Axis speeds o X and Z axis max.: 15,000 mm/min o X and Z axis min.: 0.01 mm/min Working area Ppedpozgbw Isfx Am Tow o Max. grinding length: 600 mm o Center distance: 225 mm Performance data o Grinding spindle: 1 tool for external cylindrical grinding o Tool dimensions: Ø 760 x 250 x Ø 304.8 mm o Cutting speed: 60 m/s o Power: 30 kW o Max. grinding wheel speed according to text: approx. 80 m/s Workpiece spindle o Axis speed: 5 - 1,000 min⁻¹ o Taper: 5 Morse o Motor torque: 16 N.m Tailstock & facing tool o Taper: 5 Morse o Max. tailstock quill travel: 80 mm o Diamond wheel profiler Saddle drives o Torque of X-axis motor: 28 N.m o Torque of Z-axis motor: 16 N.m Operating data o Year of manufacture: 2022 o Recorded operating hours: 7,315 o Operating pressure: approx. 6 bar General data o 3 x 400 VAC / 50 Hz / 72 kW / 119 A o Weight: 10,000 kg Peripherals • Automated workpiece removal station, JOVI, Type 1113B, year of manufacture 2022, weight approx. 300 kg • Air filter unit, IFS, Type M 1600, year of manufacture 2022, serial no. 567663, weight approx. 85 kg, connection power 380 - 460 V, 50 / 60 Hz, 0.7 kW, 1.5 - 2.1 A • Hydraulic unit, REXROTH, Type Deposito HE-16120 • Coolant filter unit, MICRONFILTER, Type EASY 250 / KMT350, year of manufacture 2022, serial no. 0201, tank volume approx. 2,300 l, connection power 400 V / 50 Hz, 2.44 kW • Immersion cooler, HASCH, Type MCS-120ST-05AOP6R7S7UZ1-3405C, year of manufacture 2022, serial no. 1003220300954, weight approx. 206 kg • Magnetic separator, MICRONFILTER, Type KMT350, serial no. 0211 • Tool loading unit, DANOBAT, Type rotary table lift, year of manufacture 2022, serial no. 3130490901, weight approx. 350 kg, max. load capacity approx. 360 kg