Used Disc Grinding Machine for sale (69,814)

Condition: used, distance table to spindle center: 650 mm, table length: 1,000 mm, table load: 400 kg, Surface grinder Brand: Jakobsen Model: 1432 Year: 1990 RPM: 1400 Grinding area: 800x400 mm Table size: 1000x350 mm Maximum table load: 400 kg Maximum workpiece height: 475 mm Wheel size: 350x50x127 mm Heidenhain ND 221B digital readout. 800x350 mm Selter electronic magnetic table with magnetization regulator. Itsdpoyzxfhefx Ampof Maximum distance between table and wheel: 650 mm MONNET filter from 2007 Includes grinding wheel sets (see photos). *Operates perfectly in automatic mode. In manual mode, the X axis is disabled; Y and Z function correctly.

Condition: used, Year of construction: 2004, 10 spindle system. Connected load: 380/400V/50Hz, 34 kW. Glass thickness: 3-60 mm. Itedpfxswynzce Ampjf

Condition: ready for operation (used), Year of construction: 1999, functionality: fully functional, machine/vehicle number: 14556, grinding wheel diameter: 400 mm, travel distance X-axis: 900 mm, travel distance Y-axis: 550 mm, travel distance Z-axis: 360 mm, grinding spindle speed: 3,400 rpm, TECHNICAL DETAILS Itsdpfsyuamxex Ampjf Travel X-axis: 900 mm Travel Y-axis: 550 mm Travel Z-axis: 360 mm Table width: 790 mm Table depth: 380 mm Max. grinding wheel diameter: 400 mm Max. spindle speed: 3,400 rpm EQUIPMENT CE marking Documentation

Condition: not inspected (used), Year of construction: 1993, machine/vehicle number: 101472, ● Terms of delivery: Free loaded onto truck ● Location: 42477 Radevormwald Itjdpfeyv Hdujx Ampsf ● Availability: By arrangement – Collection of the goods is scheduled for 06/05/2026. Unfortunately, collection outside this period cannot be considered. ● Payment terms: Advance payment by bank transfer ● Internal no.: DÄ27 ● Inspection under power: Yes Technical data: ● Magnetic chuck approx.: 500 x 250 mm ● Grinding length approx.: 600 mm ● Grinding width approx.: 250 mm ● Grinding height approx.: 500 mm Scope of delivery: ● Various grinding wheels as per pictures Dimensions & weights: ● Installation dimensions L x W x H approx.: 2200 x 1700 x 2000 mm ● Weight approx.: 1500 kg Info: There is a small chipped area on the lower handwheel; however, this does not affect functionality. If you have any questions or would like to arrange a viewing, please feel free to contact us! Additional notes: ►Transport to the destination can be offered upon request ►The offer price is net plus VAT ►The goods are sold with exclusion of any warranty ►Technical data without guarantee ►Subject to prior sale ❗The sale is strictly to business customers only❗

Condition: good (used), Year of construction: 1985, functionality: fully functional, The ELB SW 4/2 is a classic conventional surface grinding machine. Specific data may vary depending on the version (e.g., VA I, VAI-Z), but the key technical specifications typically fall within the following range: Machine type: Surface grinding machine (horizontal) Working area Grinding length: approx. 450 mm Grinding width: approx. 250 mm Max. workpiece height: approx. 280 mm Iedpfx Aoyy Aczempetf Grinding spindle Grinding wheel: Ø 250 mm × 25 mm width Bore: 51 mm Speed: approx. 1,430 / 2,900 rpm Spindle motor: approx. 2.5 kW (total power ~4.5 kW) Axis travels Vertical travel (Z): approx. 400 mm General data Total power: approx. 4.5 kW Machine weight: approx. 1,800 kg Dimensions (L×W×H): approx. 1,800 × 1,400 × 2,000 mm

Condition: excellent (used), Year of construction: 1991, functionality: fully functional, machine/vehicle number: 26BB2444, Very well maintained surface grinder with coolant tank Ijdpfx Ametk Av Aspetf

Condition: used, Year of construction: 2014, functionality: fully functional, grinding length: 600 mm, grinding width: 300 mm, Main machine data: - Table size (W x L): 600 x 300 mm - Electro-magnetic chuck: 300 x 600 x 70 mm - Grinding wheel size: 355 x 25 x 127 mm Drive performance: - Spindle motor: 2.2 kW Machine dimensions: Dimensions: - Length: 2,300 mm - Depth / Width: 1,550 mm - Height: 1,950 mm - Machine weight: 1,650 kg Standard equipment: - CNC-controlled vertical feed AD1 - Electro-magnetic chuck - Automatic demagnetizing device - Electronic cross-feed adjustment via operator panel - Coolant system with extraction, paper filter, and magnetic separator - Parallel dressing device (head-mounted) - Dressing device for table mounting - Motorized rapid traverse adjustment (vertical) Isdpfx Amsyyymwjpjtf - Grinding wheel flange - Grinding wheel - Halogen lighting - Balancing arbor - Balancing scale - 1 set of splash guards Incl. 3 grinding wheel flanges Incl. fine-pole electro-magnetic chuck 300 x 600 mm Pole pitch: 3 mm, pole width: 1 mm Instead of standard electro-magnetic chuck

Condition: excellent (used), Year of construction: 1988, functionality: fully functional, machine/vehicle number: 1, center height: 150 mm, center width: 480 mm, grinding diameter: 299 mm, New arrival 1 Hydraulic Universal External and Internal Cylindrical Grinding Machine TSCHUDIN HTG 410 U – Year 1988, partial overhaul in 2026 – 150 mm center height x 480 mm center distance – workpiece spindle head MK 5 with stepless speed adjustment. Grinding wheel left and right – swiveling internal grinding attachment with 18,000 RPM Machine equipped with four-axis digital readout – X-axis – Y-axis and rotary encoder with one-micron resolution when swiveling the universal grinding spindle head and workpiece spindle head! Pneumatic air cushion lifting for effortless swiveling of workpiece spindle head and grinding spindle head. Machine includes four-jaw chuck, halogen lamp, paper band filter, folding dresser, and balancing arbor. Guideways in X-axis newly scraped – machine thoroughly inspected by specialist. Automatic cycle with "rapid traverse to automatic infeed – dwell time – retraction – infeed dimension remains set". Very little used machine from prototype manufacturing! Price on request (Domestic sales plus 19% VAT.) Technical data not binding – subject to prior sale and errors. Itodpfx Amjvdumbopsf Best regards, INDUBA GmbH Mathias Becker D-78628 Rottweil

Condition: as good as new (ex-display), Year of construction: 2025, functionality: fully functional, grinding length: 500 mm, grinding width: 250 mm, Young, like-new demonstration machine: High-precision surface grinding machine, "Optimal" series, available at a special net price. Grinding area: 500 x 250 mm Features: ● Surface grinding machine with automatic vertical feed ● Grinding sequence: roughing – finishing – spark-out Itedoyak Dlepfx Ampsf ● Siemens S700 touchscreen panel and electronic handwheel for Y-axis ● Digital display for vertical axis Y and cross axis Z ● Table cover and splash guards in stainless steel design ● Electrical cabinet fitted predominantly with Siemens components ● Includes manual dressing device, electro-magnetic chuck, and coolant filtration system Main technical data: Grinding length mm 500 Grinding width mm 250 Distance table surface to spindle center mm 450 Table drive Hydraulic Table load kg 180 Longitudinal movement X Table speed, steplessly adjustable m/min 7 – 23 Max. longitudinal travel mm 560 Cross movement Z Max. travel speed mm/min 990 Max. cross travel mm 275 Vertical movement Y Max. travel speed mm/min 460 Grinding spindle / Grinding wheel Spindle power kW 2.2 Wheel dimensions mm 200x20x31.75 Spindle speed (speed control optional) min⁻¹ 2850 Dimensions Machine weight (net) kg 1800 Machine dimensions (inc. reciprocation) Width mm 2300 Depth mm 1650 Height mm 1680 Power connection kW 3.7 All model series include standard accessories: ● 1 standard grinding wheel ● 1 wheel flange ● 1 dressing block with diamond ● 1 balancing arbor ● 1 balancing stand ● 1 machine lamp ● 1 set of machine tools ● 1 set of documentation with spare part list ● Machine in CE-conform (metric version) Precision and surface quality at optimal price. Fully equipped for universal use in a wide range of industrial and application areas. Machine comes with a 12-month parts warranty. By the way, aside from affordable new and certified used machines, we offer even more: • On-site consultation and solution finding • Organization of machine transport to your facility • Installation, commissioning, and turnkey handover • Spare parts supply • Control training for Siemens, Heidenhain, and Fanuc • Trained service staff available in your area and more • 24/7 telephone support • Tax-optimized trade-in of your old machine • Attractive financing options, even without down payment

Condition: used, Year of construction: 1997, Catalogue number 7724 TECHNICAL DATA - number of working spindles: 6 pcs - spindles pressed pneumatically onto the material - milling units adjustable up/down, right/left, and at angles - 6 pneumatic clamps - stepless feed speed adjustment - max milling height: 130mm - max milling length: 2500mm - max milling width: 330mm - shaft diameter: 40mm Motor power: - milling units 1-2: 2 × 5.5kW Itjdpfxoya Hl Ee Ampsf - milling units 3-4: 2 × 4.5kW - milling units 5-6 universal (sanding or milling): 2 × 4.5kW - extraction nozzle diameter: 10x152mm - air supply requirement: 6-8 bar - dimensions (L/W/H): 8000x3000x2420mm - weight: approx. 6000kg ADVANTAGES – Italian manufacture – For through-feed processing of curved elements according to template – 6 milling units – Not repainted – Safety guards – Original DTR + CE documentation – Used machine in very good condition Net price: 46,900 PLN Net price: 11,160 EUR (based on 4.2 EUR exchange rate) (Prices may change depending on exchange rate fluctuations)

Condition: refurbished (used), grinding wheel diameter: 150 mm, year of last overhaul: 2026, disc diameter: 150 mm, grinding spindle motor power: 2,200 W, compressed air connection: 5 bar, The machine has been completely disassembled, all wear parts replaced, and repainted – it is in as-new condition. Sale includes a functional warranty. Main features: - For re-sharpening and re-toothing HSS segment, CV, and solid carbide saws using the CBN deep grinding process Tooth forms A, Aw, B, Bw, and C according to DIN1840 - Grinding of variable pitch teeth (option) - Grinding of special tooth shapes (option) - Grinding of carbide teeth (option) - Grinding of segment teeth (option) - Freely adjustable (programmable) tooth geometry - Grinding of repair segments on segment teeth - Deburring/chamfering alternately top/bottom or same side - Continuously variable rake and clearance angles - Advanced machine guard hood for easy opening/closing Key advantages: - Short grinding times with excellent surface finish thanks to sturdy machine design, optimised clamping flanges for the saw blades, and high drive power - Consistent, repeatable quality due to CNC control - Powerful grinding wheel drive Ijdpfepgkgqox Ampotf - Fully digital servo drives (2 CNC axes) Technical data: - Saw blade diameter: 20–550 mm - Max. saw blade thickness: 6 mm - Number of teeth: 20–999 - Working speed: 3–75 teeth/minute - Cooling: approx. 5 bar at 40 L/min - Grinding wheel drive: 2.2 kW - Dimensions (LxWxH): approx. 1750 x 1200 x 1800 mm - Weight net/gross: approx. 800 / 980 kg - Paint finish: Dove blue Accessories: - Software for grinding arc teeth, angled teeth, and cylindrical (round) grinding (software extensions available on request) - Saw blade holders diameter 400, 300, 215, 140 mm (other diameters available on request) - Reducing rings diameter 16x22, 27, 32, 40, 50 mm (others on request) - Base adapter for saw blade holders - Mechanical power clamping nut - Coolant system including high-pressure pump, mist extractor, and magnetic separator, designed for emulsion cooling - Automatic central lubrication with lubricant pressure monitoring (linear guides and ball screw) - Operating manual including wiring diagrams - Operating voltage: 3-phase current Trade-in of your used ECE 45, if available, is possible.

Condition: used, Year of construction: 2000, functionality: fully functional, Used Cylindrical Grinding Machine Reckord M 1432 B The Reckord M 1432 B is a high-performance universal cylindrical grinding machine that combines maximum precision with robust construction. With a minimum infeed setting of just 0.0025 mm and outstanding roundness accuracy, it is ideal for demanding grinding tasks in both single-part and series production. Your advantages at a glance: Maximum precision: Minimum grinding wheel infeed of 0.0025 mm ensures top surface finishes and form accuracy. Exceptional flexibility: External, internal, and face grinding – swiveling workhead (+90° / -30°) and table (+3° / -6°) for tapers and complex geometries. Robust construction: Heavy-duty machine bed weighing approx. 4,000 kg for maximum rigidity and vibration damping. Powerful drive: 4 kW grinding wheel motor for rapid stock removal and short machining times. Ergonomic operation: Clearly arranged controls for rapid operator familiarization and intuitive handling. Technical Data Manufacturer: Reckord Model: M 1432 B (Model 1000) Type: Universal cylindrical grinding machine Centre height: 180 mm Max. grinding length: 1000 mm Max. grinding diameter: 315 mm Max. workpiece weight: 150 kg Workhead speeds: 40, 72, 128, 228 rpm Grinding wheel dimensions: 400 x 50 x 203 mm Grinding motor output: 4 kW Total power consumption: 7.8 kW Machine weight: approx. 4,000 kg Machine dimensions (L x W x H): 3240 x 1760 x 1680 mm Colour: Blue (as existing) Condition: Used, fully checked and operational Availability: Immediately ex stock Stockstadt Additional Information Scope of delivery: Cylindrical grinding machine Reckord M 1432 B including standard accessories as per the operating manual. Fully checked and operational. Technical documentation: Supplied in German. Itsdoyxgldspfx Ampsf Optional services: Commissioning and training by experienced technicians, maintenance contract, as well as financing and leasing options on request. Inspection: The machine can be inspected by appointment in Stockstadt am Rhein.

Condition: refurbished (used), machine/vehicle number: 2257, Manufacturing origin France Voltage 380/50/3 Netweight 3000 kg Ijdpfsfnm Iijx Ampjtf Custom position 8460.29 20 Dimensions 2400x1550 mm TECHNICAL DATA Diameter capacity 80 mm Type 2HA : 120 mm Maximum infeed grinding length 200 mm Maximum throughfeed grinding length (with normal-type guides) 300 mm Grinding wheel : -diameter 400 mm -maximum width 200 mm -bore 203.2 mm Driving wheel : -diameter 254 mm -width 200 mm -bore 127 mm Main drive motor 11-22 kW Driving wheel motor 1,1 kW Driving wheel speed 10 – 200 U/Min Standard accessories : 1 flange with grinding wheel 1 flange with driving wheel 1 workpiece support bridge 1 set of shims for workpiece support -Hydraulic dressing and trueing device for grinding and driving wheels -Variable speed drive of driving wheel -Electrical equipment for 3x380 v, 50 Hz -Main drive motor, 11 kW -Ammeter for main drive motor Starter keys and operating manual errors and omissions excepted data given without obligation.

Condition: ready for operation (used), feed length X-axis: 920 mm, feed length Y-axis: 400 mm, Surface Grinder HIDROPRECIS Itodpfxeyz Infe Ampjf - Table: 800 x 450 mm - Y-axis travel: 920 mm - X-axis travel: 400 mm - Maximum grinding height: 500 mm - Wheel motor power: 7.5 hp - Grinding wheel: 350 x 127 x 100(50) - Coolant filter - Dimensions: 3,500 x 2,500 x 2,300 mm - Weight: 3,500 kg

Condition: ready for operation (used), Year of construction: 1990, functionality: fully functional, grinding length: 400 mm, grinding width: 150 mm, JUNG JF 415 Jung JF 415 Surface Grinding Machine with Flanges and Coolant Belt Filter * Table length: 400 mm * Table width: 150 mm Isdpfx Amjytfbfopotf * Maximum grinding length: 400 mm * Maximum grinding width: 150 mm * Maximum workpiece weight: 75 kg * Distance spindle to table: 400 mm * Table speed: 1–24 m/min * Grinding wheel diameter: 25 mm * Spindle speed: 900 – 4500 rpm * Heidenhain digital readout * Year of manufacture: 1990, machine no.: 1566

Condition: excellent (used), Year of construction: 2016, functionality: fully functional, center height: 200 mm, workpiece weight (max.): 30 kg, grinding length: 400 mm, grinding wheel diameter: 350 mm, total width: 2,600 mm, total length: 1,800 mm, grinding diameter: 100 mm, workpiece weight between centers: 30,000 g, distance between centers: 400 mm, type of input current: AC, spindle speed (max.): 1,000 rpm, spindle speed (min.): 90 rpm, grinding spindle motor power: 3,700 W, grinding spindle speed: 2,000 rpm, overall weight: 2,000 kg, pivoting range: 30 °, input voltage: 400 V, Equipment: rotational speed infinitely variable, incl. swiveling internal grinding attachment General Diameter over table: 200 mm Distance between centers (ABC): 400 mm Grinding length: 400 mm Grinding diameter (max. / min. OD): 100 / 6 mm Grinding diameter (max. / min. ID): 85 / 6 mm Max. weight between centers: 30 kg Max. weight incl. chuck: 10 kg Itodeycg A Ajpfx Ampjf Grinding spindle Grinding wheel size: 350 x 127 x 50 mm Minimum usable grinding wheel size: 300 mm Spindle speed: 1800 – 2000 rpm Spindle motor power: 3.7 kW (Peripheral) speed: 33 m/sec Rapid traverse: 40 mm Rapid traverse with handwheel: 20 mm Max. automatic infeed on diameter: 1.7 [3.4] mm Minimum diameter increment: 0.001 mm Infeed speed on diameter (coarse/fine): 0.015 – 6 / 0.015 – 3 mm/min Table Table speed: 0.1 – 5 m/min Table stroke: 450 mm Minimum travel: 2 mm Maximum table swivel range: -2° to +30° Work spindle Taper bore: MT-4 Spindle speed: 90 – 1000 rpm Spindle motor power (2-stage): 0.28/0.37 kW Including complete set of Schaublin collets DM 2.5 – 20 Incl. 3-jaw chuck Incl. flange with grinding wheel

Condition: ready for operation (used), Year of construction: 1971, functionality: fully functional, grinding length: 400 mm, grinding width: 250 mm, grinding height: 275 mm, grinding wheel diameter: 250 mm, grinding wheel width: 30 mm, ELB - Surface grinding machine, Model: SW 4 VA I, year of manufacture: 1971, grinding area: 450 x 250 x 275 mm, grinding wheel: 250 x 30 x 51 mm Ijdoyzfaljpfx Ampstf ACCESSORIES: Coolant tank with pump, electro-magnetic chuck 450 x 250 mm, leveling feet

Condition: excellent (used), Year of construction: 2006, operating hours: 53,000 h, functionality: fully functional, Full-option CNC gear grinding machine in outstanding condition, previously used in special-purpose machinery manufacturing. The machine produces up to 200 different gear types/products for special orders in batch sizes from 1 to 10,000. Manufacturer: Reishauer Model: RZ 150 Type: CNC Gear Grinding Machine Year of manufacture: 2006 Serial number: 7XXXX Machine specifications: - 2 identical workpiece spindles - Workpiece spindles with tailstocks - Turret design - Enclosed machining area - External loading and unloading station - Especially designed for run-in gearings Equipment: - Grinding worm profiling device Reishauer RP 120 - Hoffmann belt suction filter system HSF 150 - OLAER cooling unit CD35.02-NE - OLAER designation PC31.02NE-S - ELBARON extraction/filter unit RON/A2000V-2V-RH - 5-axis robotic automation (optional) Operating data: - Total operating hours: approx. 70,569.5 h - Run-time / part counter workpiece spindle / workstation 1: counter reading 01794635 - Run-time / part counter workpiece spindle / workstation 2: counter reading 002929 Hoffmann belt suction filter system HSF 150 - Connection: 400 V / 50 Hz - Phases: 3 / PE - Operating voltage: 400 V - Connected load: 31.4 kW - Nominal current: 56.9 A - Control voltage: 24 V DC - PLC voltage: 24 V DC - Valve voltage: 24 V DC - Lamp voltage: 24 V DC OLAER cooling unit CD35.02-NE / PC31.02NE-S - Year of manufacture: 2005 - Refrigerant: R134a - Fill quantity: 2.1 kg - Max. permissible operating overpressure HD: 21.7 bar - Max. permissible operating overpressure ND: 10.6 bar - Voltage: 400 V / 3 Ph / 50–60 Hz alternative: 480 V / 3 Ph / 60 Hz - Max. current: 5 A - Power: 2.5 kW ELBARON RON/A2000V-2V-RH - Year of manufacture: 07/2005 - Weight: 74 kg - Connection: 3 x 400 V AC / 50 Hz alternative: 1 x 230 V / 60 Hz - Power: 3.56 kW - Current: 7.0 A - Protection class: IP54 - High voltage max.: 9.9 kV DC - Current max.: 24.8 mA Condition: - Machine under power - Operated in single-shift to two-shift operation - Preventatively maintained - Very well-kept condition - Comprehensive documentation available Scope of delivery: - Without tools - Without production fixtures - Without grinding wheels - 5-axis robotic automation optional - Comprehensive documentation available Availability: Iodpfx Ameyxrygjpotf - Inspection by appointment - Available from 06/2026 Sales information: - Sale as seen and inspected - Warranty excluded

Condition: used, CNC surface grinding machine Isdpfxsy Apq Do Ampstf

Condition: used, Year of construction: 1984, grinding diameter 630 mm grinding length 3000 mm workpiece weight 2500 kg grinding wheel diameter 750 mm voltage 400 V Table Swivel 5° - 0° - 5° Internal Grinding Attachment Marposs Steadies Dresser Coolant Iedpfx Amoyyqhxjpetf The tech. Data are manufacturer or operator information and therefore non- binding. We reserve the right to prior sale; Our terms and conditions of sale apply exclusively. About us More than 400 of our own machines in stock Over 15,000 m² of storage space, 70 t crane capacity More than 10,000 items and accessories for your workshop If you are interested in selling machines, production lines, or your business, please contact us. You can find further offers on our website. Tours are possible by appointment. We look forward to your visit. Your Markus Hirsch Team

Condition: used, Year of construction: 1995, functionality: fully functional, Drum Grinding and Polishing Unit Manufacturer: UHLIG, Type UB 22 Year: 1995 Technical Data: Make: Werner Uhlig Model: UB 22 Isdpfx Amjyw Rhmopetf Year of manufacture: 1995 Drive: Worm gear with motor Rotational speed: 5.6 – 54 l/min Shaft diameter: 25 mm, max. torque: 34 Nm Motor power: 0.25 kW Dimensions: approx. 1.00 x 0.90 x 1.20 m Weight: approx. kg (not specified) Equipment: - Control with frequency inverter - 2 single-chamber drums, approx. 200 mm wide, diameter 260 mm - Infinitely variable drum speed - Fresh water rubber hose - Waste water drain connection All details are subject to change without notice. A demonstration under power is possible at any time in our exhibition hall.

Condition: ready for operation (used), machine/vehicle number: 4105, Grinding area: approx. 130 x 255 mm Grinding speed: 2800 rpm Table size: 150 x 300 mm Drive motor: 380 V, 1.5 kW Itsdpfx Amoh Ugwvjpsf Required space: 750 x 700 x 1700 mm Weight: about 380 kg Cup wheel Ø: 180 mm

Condition: used, machine/vehicle number: 0257391, height of centers: 160 mm distance between centers: 1500 mm grinding wheel measures: 500 x 127 x 40 mm grinding wheel rotations: 1570/2050 Upm electrical connection: 380 V kW space needed: 4400/6400 x 2000 x 1400 mm Itjdpjgayiwofx Ampsf weight: ca. 4000 kg

Year of construction: 1975, condition: ready for operation (used), machine/vehicle number: M-27 738, Center hight: 165 mm Center width/grinding length: 1000/1075 mm Gr. Grinding diameter: 250 mm Table swivel: +/- 8° Gr. Table longitudinal movement: 1210 mm Workpiece spindle stick swivel: 0 - 90° Spindle bore/cone: 38 mm/MK 5 Grinding spindle stick easily swivelling Hydr. Quick adjustment approx.: 50 mm Grinding wheel dimensions: 400 x 50 x 127 mm Itedpfx Ajd Rv Rbjmpsf 2 grinding wheel speeds due to V-belt step disc Drive power: 3 kW Space requirement: 2900 x 2200 x 1750 mm Weight: approx. 3.5 t

Year of construction: 1962, condition: good (used), machine/vehicle number: 3791, max. grinding length: 620 mm max. grinding width: 250 mm table plate chuck: 200 x 620 mm grinding plate measures: 200 x 220 x 51 mm electrical connection: 380 V, 1/1,8 kW space needed: 1650 x 1450 x 1800 mm Itedsd Ihiijpfx Ampof weight: 1350 kg