Gręžimo Staklės pirkti naudotą (48 542)

Sąlyga: geras (naudotas), Gamybos metai: 1997, TBT ML 200-2-850 Deep Hole Drilling Machine TECHNICAL DATA Model: M200-2-850 Number of spindles: 2 Drill slide travel: 850 mm Drilling method: single-lip drilling Drilling depth with: Submersible spindle: 120 mm Sealing housing: 400 mm Sealing housing with steady rest: 350 mm Spindle drive Power: 2 / 3.5 / 1.5 kW Voltage: 140 / 350 / 350 V Hsdpfjvca Rcsx Acuenu Speed: 14 / 11 / 6 / A Feed – independent drive Feed rate: 20 – 500 mm/min Rapid traverse speed (NC mode): 12 m/min Feed force: 1.5 kN Motor torque: 2.2 Nm at 3000 rpm Tailstock Motor power: 0.75 kW at 1000 rpm Spindle speed: 500 rpm Max travel: 200 mm Main dimensions L x W x H: 4600 x 2500 x 2100 mm Transport weight: 3200 kg Control: Sinumerik 805 M No liability is assumed for the correctness, completeness and timeliness of the information provided.

Sąlyga: geras (naudotas), Gamybos metai: 1985, Funkcionalumas: visiškai funkcionalus, mašinos/transporto priemonės numeris: 2803-2693, X ašies eiga: 400 mm, Y ašies eiga: 400 mm, Z ašies eigos atstumas: 400 mm, veleno greitis (maks.): 6 300 aps./min, veleno greitis (min.): 32 aps./min, plunksnos brūkšnys: 80 mm, šilko eigos atstumas: 80 mm, įvesties srovės tipas: trifazis, Įranga: dokumentacija / vadovas, For sale is a precise and robust Friedrich Deckel FP3NC tool milling machine, year of manufacture 1985, equipped with Dialog 4 CNC control. This machine is German-made and is suitable both for tool and mold making as well as for precise one-off and small-batch production. Technical Data (excerpt) Model: FP3NC Control: Deckel Dialog 4 Year of manufacture: 1985 Serial number: 12767 Spindle motor power: 2.0 / 3.0 kW, pole-switchable three-phase brake motor Spindle speeds: 31.5 – 6300 rpm (2 ranges, manually switchable) Tool holder: SK 40 Quill stroke (manual): 80 / 80 mm (horizontal/vertical) Traverse paths: X-axis: 400 mm Y-axis: 400 mm Z-axis: 400 mm Feed rate: 2 – 3600 mm/min Rapid traverse: 4000 mm/min Table T-slots: 4 slots, 14H7, spacing 63 mm Total weight: approx. 1800 kg Electrical connection: 380 V, 50/60 Hz, connected load 14.5 kVA Rated current: 22 A Control voltage: 24 V Equipment & Control 4-axis contouring operation with dialog-guided input 3D linear and circular interpolation, helical interpolation, polar coordinates Numerous drilling and milling cycles, graphical cycle input support Milling cycle "pocket contour" for pocket machining (including irregular pockets with islands) Hodsxlghpepfx Acujnu Subroutine programming, program memory up to 512 kByte Tool compensation for up to 100 tools Interfaces for cassette recorder, punched tape reader, floppy disk, or Winchester hard drive (DNC-capable) Condition & Features Machine is fully operational Precise, stable construction – ideal for workshops, training, or production Operating manual and technical documentation available Viewing by appointment possible

Sąlyga: naudotas, Gamybos metai: 1999, Funkcionalumas: ribota funkcionalumas, mašinos/transporto priemonės numeris: 990001, padavimo ilgis X ašis: 800 mm, padavimo eiga Y ašimi: 500 mm, padavimo ilgis Z ašis: 500 mm, X ašies eiga: 800 mm, Y ašies eiga: 500 mm, Z ašies eigos atstumas: 500 mm, X ašies padavimo greitis: 5 m/min, Y ašies padavimo greitis: 5 m/min, padavimo greitis Z ašis: 5 m/min, veleno greitis (maks.): 8 000 aps./min, veleno greitis (min.): 50 aps./min, bendras aukštis: 2 300 mm, bendras plotis: 2 000 mm, stalo aukštis: 850 mm, stalo apkrova: 500 kg, bendras svoris: 3 000 kg, įėjimo įtampa: 380 V, reikalingas plotis: 2 000 mm, vietos reikalavimas ilgis: 2 500 mm, reikalingas aukštis: 2 300 mm, įėjimo dažnis: 50 Hz, Parduodama patikima ir gerai pasitvirtinusi CNC frezavimo staklė Strathclyde SMT850, komplektuota su patogia naudoti Heidenhain CNC valdymo sistema. Ši staklė puikiai tinka tiksliems frezavimo darbams dirbtuvėse ar mažose gamybos linijose, reguliariai prižiūrėta. Techninė būklė – nepriekaištinga, įrenginys paruoštas iškartiniam naudojimui. Hnjdjxl Ttrspfx Acuju Šis pasiūlymas apima: - CNC staklės su Heidenhain valdymo pultu ir rankiniu pulsuojančiu generatoriumi (MPG) - Įrankių karuselė ir tvirtinimo priemonės - Įrankių komplektas: frezos, grąžtai, matavimo laikrodis - Integruotas aušinimo ir tepimo siurblys Staklę galima apžiūrėti iš anksto susitarus.

Sąlyga: geras (naudotas), Gamybos metai: 2001, Funkcionalumas: visiškai funkcionalus, gerklės gylis: 360 mm, veleno greitis (maks.): 1 270 aps./min, veleno greitis (min.): 68 aps./min, bendras aukštis: 2 350 mm, gręžimo pajėgumas: 40 mm, bendras plotis: 600 mm, bendras ilgis: 900 mm, eigos ilgis: 200 mm, veleno tvirtinimas: MK 4, gręžimo gylis: 200 mm, stalo plotis: 500 mm, stalo ilgis: 500 mm, sukimosi greitis (min.): 68 aps./min, sukimosi greitis (maks.): 1 270 aps./min, bendras svoris: 650 kg, Gręžimo našumas: Ø 40 mm Veleno tvirtinimas: MK-4 Veleno apsukos: 68 - 1 270 aps./min. Hnsdexizb Sspfx Acuou Veleno padavimas: 0,10 - 0,20 - 0,30 - 0,40 mm/aps. Veleno eiga: 200 mm Stalo išmatavimai: 550 x 550 mm Iškyša: 360 mm Kilmės šalis: Ispanija Variklio galia: 2,2 kW Staklių matmenys (I x P x A): 900 x 600 x 2.350 mm Staklių svoris: 650 kg

Sąlyga: paruoštas naudoti (naudotas), Funkcionalumas: visiškai funkcionalus, Nėra minimalios kainos – garantuotas pardavimas už didžiausią pasiūlytą kainą! Hnjdpfx Aoxnzvascuju

Sąlyga: geras (naudotas), Drilling capacity: up to 10 mm Spindle mounting: Drill chuck Speed range: Diameter of pulleys Motor side: 38; 48; 66; 78 mm Spindle side: 90; 104; 120; 133 mm Motor speed: 800 rpm Stroke: 100 mm Throat: 300 mm Table: 400 x 400 mm Distance table – drill chuck max: 580 mm Distance table – drill chuck min: 130 mm Table: 400 x 400 mm Footprint: 750 x 480 mm Total connected load: 0.4 kW Accessories/Equipment: Drill chuck Condition: Good Hnsdpfx Ajh Hrkiocusu Weight: 170 kg Dimensions: 750 x 480 x 1,450 mm

Sąlyga: geras (naudotas), Aciera 22VA precision drilling machine Hnedpfx Aceqvnqxsueu - Very well-preserved example. - Safety features up to date. - Cross table and digital readout included.

Sąlyga: labai geros būklės (naudotas), Gamybos metai: 1985, Funkcionalumas: visiškai funkcionalus, X ašies eiga: 1 200 mm, Y ašies eiga: 2 000 mm, Z ašies eigos atstumas: 700 mm, Overhauled plate boring mill from a high-end company in the aerospace industry. New control cabinet New drives New CNC control system X / Y / Z travels: 1,200 / 2,000 / 700 mm (Longitudinal travel = X, transverse travel = Y, vertical/spindle axial = Z) Further information on request Technical Data Spindle Boring spindle diameter: 100 mm Spindle taper: ISO 50 Milling spindle diameter: 185 mm Spindle axial travel: 700 mm Hnsdpfx Asxizccocueu Automatic stepless spindle and vertical feeds: 2 × 1,000 mm/min Rapid traverse, spindle and vertical axis: 5,500 mm/min Minimum spindle axis height above table level: 0 mm Maximum spindle axis height above table level: 1,500 mm Maximum distance from milling spindle nose to table center: 1,850 mm Spindle speed ranges: – Torque range: 5–14 rpm – Continuous power range: 15–1,450 rpm Number of speed ranges (continuous duty): 4 Speed ranges (rpm): 6–51 / 49–160 / 140–460 / 440–1,450 Table Rotary table dimensions: 1,100 × 1,300 mm Longitudinal travel: 1,200 mm Transverse travel: 2,000 mm Automatic stepless transverse and longitudinal feeds: 2 × 1,000 mm/min Rapid traverse longitudinal and transverse: 5,500 mm/min Automatic stepless table rotation: 30–100 °/min Rapid table rotation: 5,000 °/min Lifting Data (Assembly/Transport) Required for Group 1: – 1 steel bar Ø 70 mm × 1,600 mm length – 1 steel bar Ø 70 mm × 2,400 mm length – 4 rings for spacing the cables – 4 wire ropes Ø 22 mm Weight Group 1: approx. 12,500 kg For lifting Group 2: – two wire ropes, minimum Ø 18 mm Weight Group 2: approx. 3,500 kg For lifting Group 3: – use hand ropes Weight Group 3: approx. 1,300 kg

Sąlyga: labai geros būklės (naudotas), Visas Red Baron su 3 gręžimo galvutėmis Hnjdpfoxl Eclex Acuju

Sąlyga: geras (naudotas), Funkcionalumas: visiškai funkcionalus, padavimo ilgis X ašis: 280 mm, padavimo eiga Y ašimi: 210 mm, Schaublin 102VM with accessories Hedpfxewnfxzj Acuonu

Sąlyga: geras (naudotas), Gamybos metai: 1991, Funkcionalumas: visiškai funkcionalus, CNC frezavimo staklės HERMLE UWF 900 W Metai: 1991 Valdymas: Heidenhain TNC 360 x eiga: 600 mm y eiga: 400 mm Hnedexhcu Depfx Acuju z eiga: 420 mm Veleno konusas ISO: SK 40 Vertikalus ilgintuvas: 75 mm Sūkių diapazonas: 20 ... 4000 aps./min Veleno galva pasukama kairėn ir dešinėn: 90° kairė / dešinė eigos greitis: X/Y/Z: 1...6000 mm/min Eigos greitis: X/Y: 7 m/min, Z: 6 m/min Stalo dydis: 900 x 460 mm Maksimali stalo apkrova: 400 kg Bendra galia: 13 kW Apytiksliai matmenys (Ilgis x Plotis x Aukštis): 4,0 x 3,8 x 2,0 m Svoris apie: 2300 kg Įranga: - atskira gamybinė ląstelė - aušinimo skysčio įrenginys - valdymo pultas su svirtimi, pasukamas - matavimo zondas SK 40 Heidenhain - rankinis valdymo ratukas

Sąlyga: naudotas, Gamybos metai: 2006, Pilnas gręžimo diametras / mm Gręžimo gylis / mm Velenų skaičius / Froriep CNC giluminio gręžimo staklės – Priešapdirbimo specialistė Pagaminimo metai: 2006 Valdymas: Siemens Sinumerik 840D Maks. gręžimo gylis: 8.850 mm Ruoinio skersmuo: 150 – 900 mm Hodexgu R Ijpfx Acuenu Sukimosi greičio diapazonas: 1 – 300 aps./min Pateikimas: 0,5 – 4.500 mm/min Variklio galia: 129 kW Apsisukimo skersmuo virš lovos: 1.000 mm Spaudimo plokštės diametras: 900 mm Svoris: apie 47.000 kg Idealiai tinka tiksliam gilių skylių priešgręžimui – su spaudimo plokšte ir luneta.

Sąlyga: labai geros būklės (naudotas), Gamybos metai: 2008, TECHNICAL SPECIFICATIONS Table Clamping surface: 1200 x 450 mm Longitudinal travel: 650 mm Cross travel: 510 mm Vertical travel: 475 mm T-slots: 6 x 18 H7 Maximum load: 400 kg Distance Hnjdpfx Aewuurwocueu Between T-slots: 65 mm From spindle centre to underside of counterholder: 160 mm Feeds Longitudinal feed: 0-4000 mm/min Cross feed: 0-4000 mm/min Vertical feed: 0-1500 mm/min Rapid traverse Longitudinal: 4000 mm/min Cross: 4000 mm/min Vertical: 1500 mm/min Spindle Taper: ISO40 / DIN2079 Speed range: 55-3000 Head, swivelling: 0-140° Spindle feed Quill diameter: 90 mm Quill travel: Manual Feed: 75 mm Weight: Approx. 2300 kg SCOPE OF SUPPLY Includes, among others (list not exhaustive): ABENE milling machine Heidenhain control Toolholder set Coolant pump Levelling feet Mounting block Complete operating documentation Exact scope of supply according to photo series.

Sąlyga: labai geros būklės (naudotas), Gamybos metai: 2008, Funkcionalumas: visiškai funkcionalus, mašinos/transporto priemonės numeris: 2309-0121 / 2779 Generalüberholt, X ašies eiga: 1 200 mm, Y ašies eiga: 300 mm, Z ašies eigos atstumas: 400 mm, sukimosi greitis (maks.): 25 aps./min, sukimosi greitis (min.): 2 500 aps./min, Deckel FP3-LV tipo 2309 su aktyvia skaitmenine indikacija Šis senovinis modelis iš 1978 m. 2008 m. FPS buvo pilnai atnaujintas ir atstatytas į kaip naują būklę. Hodpfxjxnyfyj Acuonu Deckel FP 3LV – V reiškia pailgintą X eiga - su 3 ašių Heidenhain skaitmenine indikacija - bepakopis tiekimas 5 - 500 mm/min - standus kampinis stalas 550 x 1400 mm tvirtinimo paviršius - greitas eiga 1500 mm/min + lėta eiga 4 mm/min - vidinis kūgis SK40 su Deckel pjūklo sriegiu S20x2

Sąlyga: labai geros būklės (naudotas), Manufacturer: SHW Werkzeugmaschinen Model: UF 21 / UF 31 / UF 41 Travel X, Y, Z: 1000, 700, 625 mm Control system: Various versions of Heidenhain TNC 155, TNC 355, TNC 426, iTNC 530 Table: NC rotary table 1100x840 mm or fixed angle table Automatic universal milling head Quill: 120 mm Milling spindle taper: SK 50 Spindle speed: 2500 rpm As we offer several machines from this series, the images shown are for reference only and depict similar machines. Hnsdpfxeftc Uxo Acuju Please feel free to send us your specific inquiry (regarding control system, table size, tilting & swiveling devices, etc.) so we can offer a machine tailored to your requirements. MBM Maschinenservice & Gebrauchtmaschinen GmbH is an independent specialist for SHW machine tools. Our core expertise is in tool milling machines. Our services include, among others, spare parts supply, on-site customer service, machine overhauls, and control system retrofits. Services: - Used machines - Spare parts - Customer service - Machine service - Machine overhauls - Control system modernization _____ Used machine – used milling machine – used universal milling machine – universal head – metalworking – tool milling machine – milling head – SHW machine – console milling machine – rotary table – NC rotary table – SK50 – SHW spare parts – used milling machine – used fraesmaschine – used CNC milling machine – used drilling milling machine – used metal milling machine – used metal milling – used metal milling machine – used CNC milling – CNC milling machines – SHW UF – Heidenhain – MBM milling machine – MBM machine

Sąlyga: geras (naudotas), Gamybos metai: 1978, A genuine, high-quality boring mill of excellent construction. Hnodpshh Dqhofx Acuou

Sąlyga: paruoštas naudoti (naudotas), Funkcionalumas: visiškai funkcionalus, ašies skaičius: 7, X ašies eiga: 2 500 mm, Y ašies eiga: 1 300 mm, Z ašies eigos atstumas: 150 mm, Įranga: CE žymėjimas, Pasiūlymo pateikimas įpareigoja laiku atsiimti įrangą iki 45-osios kalendorinės savaitės pabaigos! TECHNINĖS SPECIFIKACIJOS Darbinė zona X: 2 500 mm Darbinė zona Y: 1 300 mm Darbinė zona Z: 150 mm Frezavimo ašių skaičius: 7 ĮRENGINIO DUOMENYS Pagrindinio variklio galia: 6 kW Hnodpfoxgdyxox Acuju ĮRANGA Atliekų konvejeris CE ženklinimas

Sąlyga: naudotas, Gamybos metai: 2004, Full boring diameter: 200 mm Drilling depth / mm Number of spindles / Technical data Power: 129 kW Control system: Siemens NC control Speed range (stepless): 2 - 300 rpm Feed range (in steps): 3 - 4500 mm/min Oil system capacity: 20,000 liters Maximum flow rate: 1,500 l/min Swing diameter in steady rest: 1,100 mm Swing diameter over bed: 1,250 mm Center distance: 11,000 mm Faceplate clamping diameter: up to 1,100 mm Max. workpiece weight with one fixed steady: 10 t Clamping range of the two steady rests: 150 - 1,100 mm BOZA clamping range: 1 = 200 - 400 mm 2 = 400 - 800 mm Dimensions Min. outside diameter: 406 mm Max. outside diameter: 850 mm Wall thickness: 10 to 150 mm Max. workpiece length: 11,000 mm Hnjdpfx Acexgic Eouju Max. workpiece weight: 10 t Max. tensile strength: 800 N/mm² Specific cutting resistance (Ks): 2000 to 2100 N/mm² Machine data Machine length: 28,800 mm Center height: 560 mm Swing diameter over bed: 1,120 mm Full boring diameter: 200 mm Core drilling diameter: 350 mm Boring diameter without predrilling: 350 mm Boring diameter with predrilling: 350 mm Headstock: Main drive motor: Siemens Type: 1 PH 7228 Performance data at 1,000 min: 113 kW / 1,079 Nm Performance data at 1,150 min: 129 kW / 1,017 Nm Main gearbox: Z-F shifting gearbox Type: 2 K210 Switchable gear ratios: i = 1:1 i = 1:4 Fixed gearbox stage headstock: i = 11.68 Max. torque: 50,000 Nm Speed range I: 2...300 min Speed range II: 2 ...75 min

Sąlyga: naujas, Gamybos metai: 2015, Funkcionalumas: visiškai funkcionalus, mašinos/transporto priemonės numeris: 15VWL1032, The machine includes fixtures for the production of electrofusion couplers within the following ranges: 250 - 800 mm SDR11 355 - 1200 mm SDR17 900 - 1200 mm SDR26 The offer also includes original MSA drawings. The VWL 1200 is a vertical three-axis CNC-controlled machine for laying electrofusion fittings, designed for the installation of medium-sized to large fittings or pipes. The machine can produce fittings typically within an internal diameter range of 250 to 1400 mm (1400 mm SDR17). Optionally, a 2-axis CNC drilling unit is available for drilling fusion indicator holes during the wire laying cycle or for drilling terminal holes during the external profiling cycle. The VWL 1200 uses special fixtures that are clamped onto an innovative component, which constitutes an integral part of the coupler’s structure, resulting in a separate fusion zone in each half of the coupler. The wire laying process begins at one terminal at the end of the coupler. The wire is inserted at double the required pitch to the end of the merging zone; the tool system then rotates and moves in the opposite direction between the first laid pitch up to the rest position at the second terminal. The process is completed in the second half of the coupler. Hodpfeu Itk Rex Acuonu The VWL 1200 system is designed to allow loading and unloading of larger couplers (which can weigh up to approximately 300 kg even before wire insertion). The machine features a completely open top section, enabling easy overhead loading via a gantry system. Alternatively, parts can be loaded through the exceptionally wide operator doors using suitable gripping and handling equipment.

Sąlyga: naudotas, Gamybos metai: 2021, Condition: used Year of manufacture: 2021 Stock number: 3965 Delivery time: prompt, subject to prior sale Country of origin: Taiwan Price: €15,600 In stock: 1 Special price: €12,480 Drilling capacity (steel): 42 mm Spindle taper: MK 4 Throat: 280 - 1,100 mm Speeds: 44 - 1,500 (12) rpm Tapping capacity - steel: M25; cast iron: M38 Length: 1,880 mm Width: 870 mm Height: 2,210 mm Weight: 1,800 kg Table to spindle distance: 470 - 1,270 mm Automatic feed: 0.05 - 0.15 (3) mm/rev Spindle motor: 2.2 kW Column diameter: 260 mm Quill stroke: 280 mm Table size: 1,725 x 715 x 180 mm Lifting motor: 0.75 kW Cube table dimensions: 635 x 520 x 415 mm Maximum height: 2,530 mm DEMONSTRATION MACHINE Right- and left-hand rotation Automatic feed Drilling depth stop Manual spindle head transverse movement with mechanical clamping Electric height adjustment of the arm with mechanical clamping Mechanical clamping of arm swivel movement Central control panel at the machine front Load indicator for drill spindle Handwheel for fine quill feed Coolant device Machine lamp Cube table Machine and equipment in accordance with CE regulations Operating instructions in GERMAN and ENGLISH Hnsdpfx Acjw Np Nxousu

Sąlyga: geras (naudotas), Table size: 1100 x 1300 mm Travel range: 1300 x 1300 mm Hsdjh T T Aqspfx Acujnu Spindle travel: 500 mm

Sąlyga: naudotas, Gamybos metai: 2006, Full drilling diameter / mm Drilling depth / mm Number of spindles / 2-machine package: Froriep deep hole drilling machine & Irle finishing machine Perfectly matched duo for deep hole drilling and precise finishing of large workpieces For sale is a specialized machine package – two perfectly coordinated systems for complete machining of long, heavy workpieces with the highest requirements for precision and efficiency. MACHINE 1 Froriep CNC Deep Hole Drilling Machine – The Pre-machining Specialist Year of manufacture: 2006 Control: Siemens Sinumerik 840D Max. drilling depth: 8,850 mm Workpiece diameter: 150 – 900 mm Speed range: 1 – 300 rpm Feed rate: 0.5 – 4,500 mm/min Drive power: 129 kW Swing diameter over bed: 1,000 mm Chuck diameter: 900 mm Weight: approx. 47,000 kg Ideal for precision pre-drilling of deep holes – including faceplate, steady rest MACHINE 2 Irle Machine – High-Precision Finishing Power: 129 kW Control: Siemens NC control Speed range: 2 – 300 rpm (stepless) Hnodpfxjuddims Acusu Feed rate: 3 – 4,500 mm/min (stepped) Center distance: 11,000 mm Swing diameter over bed: 1,250 mm Steady rest clamping range: 150 – 1,100 mm Workpiece length: up to 11,000 mm Workpiece weight: up to 10 tons Max. external diameter: 850 mm Perfect for fine boring, honing, and demanding finishing processes with up to 50,000 Nm torque. Your advantages at a glance - Complete solution from a single source – from pre-drilling to final machining - Large workpieces up to 11 meters and 10 tons - High process reliability due to perfect machine synchronization - Ready for immediate use, well-maintained, and from ongoing operation - Ideal for mechanical engineering, energy, oil & gas, hydraulics, and large part manufacturing

Sąlyga: naudotas, Gamybos metai: 2017, Condition: Used Year of manufacture: 2017 Stock no.: 3901 Country of origin: China Price: €8,490 In stock: 1 Special price: €6,790 Drilling capacity in steel: 32 mm Spindle taper: MT 4 Arm reach: 300 - 1,000 mm Speeds: 32 - 2,500 rpm (16 steps) Length: 1,760 mm Hnodpfewiqlpsx Acuou Width: 800 mm Height: 2,080 mm Weight: 1,600 kg Distance table to spindle end: 530 - 1,000 mm Spindle motor: 2.2 kW Column diameter: 240 mm Quill stroke: 250 mm Lift motor: 0.75 kW Feeds: 0.10 - 1.25 mm/rev (8 steps) Box table: 600 x 455 x 455 mm Coolant system Machine lamp Mechanical clamping for height adjustment and spindle head Electric clamping for arm rotation Machine and equipment comply with CE regulations Operating manual in GERMAN and ENGLISH

Sąlyga: geras (naudotas), Manufacturer: MAS Model: VR 4 Arm reach: 1000 mm Hnsdpfx Aeh Eigbjcuju without table!

Sąlyga: geras (naudotas), Outreach: 915 mm Morse taper: 3 Length: 1700 mm Width: 1,000 mm Height: 2000 mm Hnodjd Ixy Ijpfx Acusu Weight: 1000 kg