Prod-Masz Abkantbank 3M, Biegemaschine Bender 3M, Stroj Za Upogibanje Bender nakup rabljenega (88.060)

Leto izdelave: 2009, stanje: pripravljen za uporabo (rabljen), Working height: 1035 mm, usable width: 6000 mm, max. usable length: 6000 mm, max. wire diameter: 12 mm, max. tensile strength: 650 N/mm², bending capacity (number of bars): Ø12 mm: 40 bars, Ø10 mm: 60 bars, Ø8 mm: 90 bars, Ø6 mm: 150 bars, Ø5 mm: 200 bars. Geometry/bending data: smallest leg between two angles: 50 mm (with bending finger Ø17 mm), standard bending finger: No. 60, Ø40 mm. Number of programmable bending angles: 20, memory locations: 100. Speeds: first speed: 45°: max. 5.8 s, 90°: max. 8.7 s, 180°: max. 13.7 s; second speed: 45°: max. 2.9 s (complete cycle forward/back), 90°: max. 4.4 s (complete cycle forward/back), 180°: max. 6.8 s (complete cycle forward/back). Mechanics/hydraulics: 4 double-acting hydraulic cylinders, hydraulic unit with pumps, solenoid valves, pressure regulators, safety valves, delivered without oil. Operation/control: control panel with keypad and numeric display, manual and automatic operation, foot pedal control, emergency stop button and emergency stop foot pedal. Installed power: 5.5 kW. Length: 6705 mm, width: 710 mm, height: 1035 mm, weight: 1220 kg, oil tank capacity: 60 l. Electrical connection: phases: 3x6 mm², ground: 1x6 mm². Equipment: support frame with control cabinet and hydraulic unit, fixed and movable bending bar, standard spare parts kit, foot pedal (1x) + emergency stop foot pedal (1x). Documentation available, on-site inspection possible. Iedpfey A Slwox Al Netf

Stanje: kot nova (razstavni stroj), Leto izdelave: 2026, Širina lima 2050 mm Debljina lima 4,5 mm Debljina savijanja lima 4,0 mm Dužina valjaka 2050 mm Najmanji prečnik 210 mm Prečnik gornjeg valjka 140 mm Težina 1530 kg Dimenzije D-Š-V 3220 x 1200 x 900 mm Izložbena mašina iz 2026. godine sa samo oko 2 radna sata Stanje kao NOVO Specijalna cena na upit Oprema: - robusna elektro-mehanička mašina za kružno savijanje - 2 centralna valjka na elektro pogon (gornji i donji valjak) - Gornji valjak se ručno otklanja, sa preklopnim ležajem - uključuje uređaj za konusno savijanje - mobilna upravljačka konzola - Donji valjak se ručno podešava, pomoću ručnog točka Itjdpfsxaawgsx Al Njf - asimetrični raspored valjaka - samokočeći glavni motor - sigurnosni uređaj (sigurnosno uže sa prekidačem) - CE znak/izjava o usklađenosti Specijalna oprema uključena u cenu: - kaljeni valjci - motorizovano bočno podešavanje valjka - digitalni prikaz pozicije za motorizovano podesivi bočni valjak

Stanje: novo, Press force: 28 t Piston stroke: 180 mm Piston diameter: 130 mm Table size: 300 x 550 mm Working speed: 2 - 9.8 mm/sec Return speed: 20 mm/sec Maximum pressure: 200 bar Bending capacity - flat bar: 200 x 10 mm Machine weight: approx. 800 kg Dimensions: approx. 1150 x 1103 x 750 mm NC control for setting the piston stroke and storing up to 100 programs Selector switch for manual or semi-automatic operation Flow control valve and pressure relief valve Integrated pressure gauge Work table with angle division Back gauge Itsdpfx Aoqzmgqjl Nof

Stanje: pripravljen za uporabo (rabljen), Leto izdelave: 2001, Sheet width: 3200 mm Sheet thickness: 3.0 mm (steel) Sheet thickness (stainless steel): 2.0 mm Itjdpsxabz Tofx Al Nef Opening width / upper beam: 300 mm OW speed: 40.0 mm/sec Bending beam adjustment: 80.0 mm Working height: 900 mm BW speed: 90.0 deg/sec Control: MULTIBEND 5000 Backgauge – adjustable: 10 - 1550 mm Accuracy: +/- 0.1 mm Air pressure: 5.0 bar Operating hours: approx. 1,000 h Voltage: 400 V Total power requirement: 2 x 4.0 kW Weight: 4,400 kg Dimensions (L-W-H): 4295 x 2225 x 1775 mm Original price: approx. €85,000 Machine with only around 1,000 operating hours (!!) Good condition (!!) Special price on request - Supplied in tested condition - Machine video - ?v=VP6emx4HTYM ! Maximum flexibility when bending panels, boxes, and profiles ! High flexibility in part design ! High productivity and throughput ! Easy to operate Equipment: - Motorized universal swivel bending machine "RAS 73.30" * High-precision mechanics with modern control technology * For single-piece and series production * Robust high-speed model with rapid axis movements * Torsion-resistant welded construction - RAS CNC control model "MULTIBEND 5000" * Material and tooling library * Swivels – front right * 1x emergency stop button - CNC electro-motorized upper beam adjustment * Fast opening and closing speed * Programmable opening and closing height * Radius bending without special tools (multi-step bends) * Rigid upper beam for precise bends * 1x set RAS segmented upper tools, height 80 mm * RAS "Klick-In" tool system (pneumatic) - CNC electro-motorized bending beam adjustment * Rapid swinging motion: short production times * Crowning system compensates for deformation due to bending forces * 1x set RAS segmented bending tools - CNC electro-motorized backgauge * Quick positioning, high repeatability * Table sheets support the weight of the material * Table sheets made of stainless steel with ball rollers - 2x free-moving double foot switches - 1x RAS tool trolley for bending tools (mobile) - Operating manual (PDF) + original circuit diagram

Stanje: novo, Bending diameter – max. 36.0 mm steel Cutting thickness – max. 36.0 mm steel Motor speed: 1450 rpm Oil capacity: 32.0 l Motor: 380 Volt, 50 Hz Total power requirement: 5.5 kW Weight: 650 kg Dimensions (L x W x H): 1470 x 1200 x 1020 mm Demonstration machine – NEW (!!) Features: - Maximum performance, minimal energy consumption - Hydraulic combination machine for bending and cutting operations * Suitable for e.g. reinforcing steel or solid material - Bending mode with 3 different angle settings - Selectable manual and automatic modes - Simultaneous bending and cutting operations possible when the machine is running - “ECO mode”: Hydraulic pump operates only when the foot switch is activated - Free-moving foot switch - Instruction manual Itjdexabntjpfx Al Nof Technical data: - Steel 45 kg/mm²: Bending Ø 36.0 mm / Cutting Ø 36.0 mm * For 2 pieces: Steel 45 kg/mm²: Bending Ø 20.0 mm / Cutting Ø 24.0 mm - Steel 65 kg/mm²: Bending Ø 32.0 mm / Cutting Ø 32.0 mm * For 2 pieces: Steel 65 kg/mm²: Bending Ø 18.0 mm / Cutting Ø 20.0 mm - Steel 85 kg/mm²: Bending Ø 26.0 mm / Cutting Ø 28.0 mm * For 2 pieces: Steel 85 kg/mm²: Bending Ø 14.0 mm / Cutting Ø 18.0 mm * Machine video: ?v=zagTSA81VyA

Stanje: pripravljen za uporabo (rabljen), Leto izdelave: 1966, Na voljo je valjčni in upogibni stroj Häusler. Število valjev: 3, vztrajnostni moment: 46 cm², maks. kapaciteta za ploščati material pri 1000 mm: 100 mm/20 mm, maks. kapaciteta za cevi pri 900 mm: 102 mm/6 mm, maks. kapaciteta za kvadratni material pri 600 mm: 60 mm/60 mm, maks. kapaciteta za T-profil pri 1200 mm: 1200 mm/1200 mm/13 mm, premer osi: 125 mm-135 mm, dimenzije stroja (D/Š/V): pribl. 4500 mm/1700 mm/1500 mm, teža: pribl. 6500 kg. Možen je ogled na lokaciji. Itodpfx Alsy Ax U Ee Njf

Stanje: rabljeno, Leto izdelave: 2011, Širina pločevine 1270 mm Itsdpfx Aloyv Nq Rs Njf Največja debelina pločevine 4,5 mm Predupogib 4 mm Premer valjev 120 mm Hitrost valjanja 8 obr/min Minimalni premer upogibanja 180 mm Skupna moč 2,2 kW Teža stroja cca 1250 kg Dimenzije 2470 x 750 x 1000 mm

Stanje: rabljeno, Leto izdelave: 1992, Sheet width: 2050 mm Sheet thickness: 10.0 mm (steel) Bending capacity: 8.0 mm (steel) Top roller diameter: approx. 205 mm Side roller diameter: approx. 195 mm Control: conventional Oil capacity: 80.0 liters Voltage: 380 V Total power requirement: 5.5 kW Weight: 3200 kg Dimensions (L x W x H): 4500 x 1500 x 1300 mm Features: - Robust electro-hydraulic 3-roll plate bending machine - 3-roll concept enables a wide range of bending and rounding operations - Swiveling control unit at the front Itedpfjxacdvjx Al Nof * Operation and control of all rollers and machine axes * Digital position display * Manual operation via joysticks - Bending diameters of up to 1.1 times the top roller diameter possible - Forged and hardened rolls with a strength of 53-55 HRC - Low-maintenance, stable machine design - Heavy-duty steel welded construction - Electro-hydraulic drop-end for easy removal of rolled pipes - Manometer / pressure gauge for the rolls - Safety device (safety cable with switch unit) - Operating manual (PDF)

Stanje: novo, Širina pločevine 1550 mm Debelina pločevine 4,5 mm Upogibanje 4,0 mm Dolžina valjev 1550 mm Najmanjši premer 190 mm Premer zgornjega valja 130 mm Teža 1265 kg Dimenzije 2670x1110x1050 mm Itsdpfx Aljyvvrhe Nsf Oprema: - Centralni valji poganjani preko elektromotorja, planetnega reduktorja in zobniškega pogona - Zgornji valj izhodno zložljiv na stran - Glavni motor z zavorno napravo - Naprava za konusno upogibanje - Mobilna upravljalna konzola in nožno stikalo - CE oznaka/Izjava o skladnosti Posebna oprema: - Indukcijsko kaljeni valji - Motorizirana nastavitev zadnjega valja - Digitalni prikaz za zadnji valj

Stanje: novo, Širina pločevine 2050 mm Debelina pločevine 4,5 mm Upogib 4,0 mm Najmanjši premer 210 mm Premer valjev 140 mm Teža stroja ca. 1530 kg Dimenzije ca. 3220x1200x900 mm Itjdpoyvvrbsfx Al Nef Standardna oprema: - Osrednji valji poganjani z elektromotorjem, krožnim menjalnikom in zobniškim pogonom - Zgornji valj se lahko iztegne bočno - Glavni motor z zavorno napravo - Naprava za stožčasto krivljenje - Mobilna upravljalna konzola in stopalka - CE oznaka/izjava o skladnosti Dodatna oprema: - Motorni premik zadnjega valja - Digitalni prikaz za zadnji valj - Indukcijsko kaljeni valji

Stanje: novo, Širina pločevine: 1250 mm Debelina pločevine: 5,5 mm Upogibna zmogljivost: 5,0 mm Dolžina valjev: 1280 mm Najmanjši premer: 210 mm Premer zgornjega valja: 140 mm Teža: 1365 kg Dimenzije (D-Š-V): 2.020 x 900 x 1.200 mm Standardna oprema: - Centralni valji gnani z električnim motorjem, cirkulacijski reduktor in Itodpfx Aeyvvpyjl Nsf zobniški pogon - Stransko izmetljiv zgornji valj - Glavni motor z zavornim sistemom - Naprava za konično upogibanje - Mobilna nadzorna plošča in nožni pedal - CE znak/Izjava o skladnosti Posebna oprema: - Motorizirano nastavitev zadnjega valja - Digitalni prikaz za zadnji valj - Indukcijsko kaljeni valji

Stanje: novo, Kotna jekla 50x5 mm Kvadratni material 50x40x3 mm Ravno I-jeklo 120x15 mm I-jeklo pokonci 60x10 mm Okrogli material Ø 35 mm Premer cevi Ø 70x2 mm Iedpfjyvvnisx Al Netf Premer valja 155 mm Premer osi 50 mm Hitrost upogibanja 4,3 m/min Skupna potrebna moč 1,5 kW Teža 400 kg Dimenzije D x Š x V 830x730x1350 mm Oprema: - Posebna kaljena jeklena vretena - En komplet kaljenih valjev - Spodnji valji so gnani - Stranska usmerjevalna kolesa - Nožni pedal - Horizontalno in vertikalno delo - CE oznaka/izjava o skladnosti - Navodila za uporabo v nemščini

Stanje: rabljeno, Leto izdelave: 2021, številka stroja/vozila: 522-116699, sestavljeno iz: okvirne police, nakladalnega magazina: 15-mestni, največja dolžina nakladanja: 6.000 mm, avtomatsko podajanje, upogibna enota, moč: 3,87 kVA, lastna teža: 2.530 kg, z ločeno upravljalno enoto, tip: MBF372, krmilna omara z enoto za hlajenje, proizvajalec RITTAL Itsdpfjy Aqagsx Al Nef

Stanje: pripravljen za uporabo (rabljen), Leto izdelave: 2017, Funkcionalnost: popolnoma funkcionalen, številka stroja/vozila: 354, skupna dolžina: 2.150 mm, skupna višina: 1.600 mm, skupna širina: 850 mm, proizvajalec krmilnikov: Siemens, Oprema: CE označba, PODROBNOSTI O STROJU Proizvajalec krmiljenja: Siemens Tip krmiljenja: CNC Moč motorja: 4,0 kW Mere & teža Mere (D x Š x V): 2.150 x 850 x 1.600 mm Transportna teža: 800 kg Transportni paketi: 1 Isdpfx Ajy Avuvel Nstf OPREMA Dokumentacija CE certifikat

Stanje: dober (rabljeno), Funkcionalnost: popolnoma funkcionalen, Leto izdelave: 1998, radij upogibanja (maks.): 600 mm, dolžina vpenjala: 1.200 mm, debelina stene: 8 mm,

Stanje: novo, Cesurbend 3-Roll Plate Bending Machine MRS 1250 x 140 Itsdpfsh Timpex Al Nef Technical Specifications: Special equipment included in the price: hardened rolls motorized rear roll adjustment digital display Sheet width: 1250 mm Sheet thickness: max. 5.5 mm Pre-bending thickness: 5.0 mm Roll length: 1250 mm Roll diameter: 140 mm Weight: 1150 kg Dimensions (L x W x H): 2020 x 900 x 1200 mm Motor: 2.2 kW Equipment: Top and bottom rolls electrically driven Swiveling top roll Cone bending device Asymmetrical roll arrangement Self-braking main motor Separate control and operating panel Safety wire CE mark

Stanje: dober (rabljeno), Stroj za krožno upogibanje, stroj za upogibanje profilov, upogibni stroj, orodje za upogibanje cevi, upogibnik cevi, stroj za upogibanje cevi, stroj za upogibanje cevi z jedrom -Proizvajalec: Dako Gedore, elektrohidravlični upogibnik cevi na mobilnem podvozju -Premer cevi: 3/8" do 3" -Hod: 320 mm -Motor: AEG 1,5 kW Iedpfx Aljx Nfhro Netf -Dodatki: vklj. čeljusti za upogibanje do 2,5", glej slike -Transportne mere: 1140/1045/H1200 mm -Skupna teža: 389 kg

Stanje: dober (rabljeno), Leto izdelave: 1982, Širina pločevine 2000 mm Debelina pločevine 2 mm Razdalja med stojali 2080 mm Skupna potrebna moč 2,2 kW Teža stroja cca 2,8 t Potrebni prostor cca 3,0 x 1,2 x 1,5 m Hidravlični upogibni stroj - Maksimalne dimenzije upogibane pločevine: 2000 x 2 [mm] - Moč elektromotorja: 2,2 kW - Kot upogibanja: 0 – 180 stopinj Itedpfx Aljw N S Eij Nef

Stanje: novo, Condition: New Delivery time: approx. 12 weeks from order Country of origin: Turkey Price: €15,900 Itsdpfx Aoyn R E Ssl Nef Lease rate: €305.28 Shaft diameter: 50 - 60 mm Top roller diameter: 180 mm Roller diameter: 180 mm Lower roller diameter: 180 mm Driven rollers: 3 Motor power: 3.75 kW Speed: 6 m/min Flat bar upright (cross-section / min. diameter): 60x10 mm / 500 mm; 20x5 mm Flat bar flat (cross-section / min. diameter): 80x20 mm / 500 mm; 50x5 mm Square bar (cross-section / min. diameter): 32x32 mm / 400 mm; 12x12 mm Round bar (cross-section / min. diameter): Ø 35 mm / 350 mm; Ø 10 mm Tube (cross-section / min. diameter): Ø 60x2 mm / 600 mm; Ø 15 mm Rectangular tube upright (cross-section / min. diameter): 50x25x3 mm / 450 mm; 20x1 mm Square tube (cross-section / min. diameter): 45x3 mm / 600 mm; 20x2 mm Angle iron legs out (cross-section / min. diameter): 60x60x6 mm / 650 mm; 30x3 mm Angle iron legs in (cross-section / min. diameter): 50x50x5 mm / 550 mm; 30x3 mm UPN legs out (cross-section / min. diameter): UPN 80 / 600 mm; UPN 30 / ... UPN legs in (cross-section / min. diameter): UPN 65 / 600 mm; UPN 30 / ... IPN flat (cross-section / min. diameter): IPN 80 / 600 mm Length: 1200 mm Width: 850 mm Height: 1200 mm Weight: 955 kg 3 driven rollers (brake motor) Hardened drive shafts Hydraulic adjustment of the two lower rollers Hardened universal rollers Lateral straightening rollers, manually adjustable in 3 axes Usable in horizontal and vertical position Digital display for lower roller positions Machine and equipment compliant with CE regulations Operating manual in GERMAN and ENGLISH

Stanje: rabljeno, Leto izdelave: 1993, Upogibni radij R 36 - R 150 Iodpfxjyx Ip De Al Njtf Hitrost upogibanja 4,5 obr/min Število programov 3 Upogibna zmogljivost za jeklene cevi 6 - 33,7 mm Potreben prostor pribl. 600 x 260 x 900 mm Teža stroja pribl. 110 kg Oprema/pribor: - Nožno stikalo - Podnožje S sledečimi orodji: 1 kos 25 mm, R80 1 kos 18 mm, R45

Stanje: novo, Condition: New Delivery time: approx. 10 weeks from order Country of origin: Turkey Price: €63,900 Leasing rate: €1,207.71 Bending length: 4,200 mm Sheet thickness (420 N/mm²): 1.5 mm Max. sheet thickness – stainless steel: 1 mm Max. sheet thickness – aluminium: 2 mm Drive: Motorized Length: 5,450 mm Width: 2,200 mm Height: 1,900 mm Weight: 5,350 kg Backgauge: 1,000 mm CNC CONTROL WITH TABULAR PROGRAMMING - 15.6" touchscreen on swivel arm - Tabular programming via input of the respective axis values - Open or closed hemming function - Multi-radius functions for folding or bending - Programming of material quality, sheet thickness, springback, bending corrections, and creation of a database for various material types, sheet thicknesses, and sheet lengths - Piece counter - Password authorization - 128GB HDD, providing virtually unlimited storage capacity - Remote maintenance via WLAN - Detailed alarm, tool, and parameter pages Motorized drive (servo motors) for upper beam and bending beam (Z and Y axis) Motorized backgauge (X axis) with servo motor, 1,000 mm, rectangular configuration, with ball rolls in the sheet metal trays Upper beam opening 220 mm (without tools) Manual bending beam adjustment 35 mm Upper beam with 45° geometry Continuous upper tool rail 20° with R1 2 pcs. bending beam rails (7 or 10 mm, 15 or 25 mm) Front light curtain protection Three-way foot pedal OPTIONS: Segmented gooseneck rails Pneumatic tool clamping Segmented lower and bending tools Servo drive for the bending beam Manual crowning system Second foot pedal Side gauge Rear light curtain protection 2D or 3D graphic control Itjdpfxewirrqe Al Nsf PC software Special omega geometry for lower and bending tools Tapered backgauge Backgauge extension Vacuum holder

Stanje: novo, Condition: New Delivery time: approx. 10 weeks from order Country of origin: Turkey Price: €53,600 Leasing rate: €1,013.04 Bending length: 2,050 mm Sheet thickness (420 N/mm²): 3 mm Max. sheet thickness - stainless steel: 2 mm Max. sheet thickness - aluminium: 4 mm Drive: Motorized Length: 3,350 mm Width: 2,200 mm Height: 1,900 mm Weight: 3,800 kg Backgauge: 1,000 mm CNC CONTROL WITH TABULAR PROGRAMMING - 15.6" touchscreen on swivel arm - Tabular programming by input of respective axis values - Open or closed hemming function - Multi-radius functions for hemming or bending - Programming of material type, sheet thickness, springback, bending corrections, and creation of a database for different material types, sheet thicknesses, and sheet lengths - Piece counter - Authorization via password - 128GB HDD, virtually unlimited storage capacity - Remote maintenance via WiFi - Detailed alarm, tool, and parameter pages Motorized drive (servo motors) for the upper beam and bending beam (Z and Y axis) Iodowiq E Nspfx Al Notf Motorized backgauge (X axis) with servo drive, 1,000 mm, rectangular configuration, with ball rollers in sheet platforms Upper beam opening: 220 mm (without tools) Manual adjustment of bending beam: 35 mm Upper beam with 45° geometry Continuous upper tool rail, 20° with R1 2 pcs. bending beam rails (7 or 10 mm, 15 or 25 mm) Front light curtain protection 3-position foot pedal OPTIONS: Segmented gooseneck rails Pneumatic tool clamping Segmented lower and bending tools Servo drive for bending beam Manual crowning system Second foot pedal Side stop Rear light curtain protection 2D or 3D graphical control PC software Special Omega geometry for lower and bending tools Tapered backgauge Backgauge extension Vacuum holder

Stanje: rabljeno, Sheet width 3200 mm Itodpfx Alor Ngtfe Njf Sheet thickness 2.5 mm Machine weight approx. 3.5 t Tools have been newly reground Bending angle preselection via potentiometer

Stanje: novo, Condition: New Delivery time: approx. 12 weeks from order Country of origin: Turkey Price: €11,800 Leasing rate: €226.56 Shaft diameter: 60 mm Upper roll diameter: 215 mm Lower roll diameter: 215 mm Driven rolls: 3 Motor power: 1.5 kW Speed: 4 m/min Flat bar upright (section / min. diameter): 80x20 mm / 1200 mm; 40x10 mm Flat bar flat (section / min. diameter): 120x25 mm / 600 mm; 50x mm Square steel (section / min. diameter): 50x50 mm / 800 mm; 20x20 mm Round steel (section / min. diameter): Ø 50 mm / 800 mm; Ø 20 mm Tube (section / min. diameter): Ø 100x2 mm / 1600 mm; Ø 6 mm Rectangular tube upright (section / min. diameter): 80x40x3 mm / 1400 mm; 40x mm Rectangular tube square (section / min. diameter): 70x3 mm / 1600 mm; 40x2 mm Angle steel, leg outside (section / min. diameter): 70x70x7 mm / 1000 mm; 40x mm Angle steel, leg inside (section / min. diameter): 70x70x7 mm / 1200 mm; 40x mm Itodpfx Aljwiq S Nj Nof Length: 1000 mm Width: 1400 mm Height: 1650 mm Weight: 950 kg 3 driven rolls (brake motor) Hardened drive shafts Hydraulic adjustment of the top roll Hardened universal rolls Side straightening rollers in one axis, adjustable manually Usable horizontally and vertically Foot pedal for forward and reverse operation Machine and equipment conform to CE regulations Operating manual in GERMAN and ENGLISH

Leto izdelave: 2012, stanje: rabljeno, Proizvajalec: ROSENBERGER, Tip: RB20-LR, Leto izdelave: 2012, Št. stroja: M1053, 2 CNC upogibni glavi, Zmogljivost upogibanja Ø 30 x 2 mm (jeklo), Poljubne upogibne ravnine znotraj skupne višine orodja 138 mm, Hodi X/Y/Z: 1.416 x 260 x 1.170 mm, Glava s vpenjalom in podajnim vozičkom, Siemens S7-300 PLC krmiljenje, zaslon na dotik, vhodni taktni transportni trak, robot Motoman s krmilnikom, tip SK16, Teach-In terminal MRC, izsekovalna postaja TOX, varnostne naprave, zaščitne ograje, električne in upravljalne omare, omara za dodatno opremo z 8 predali. Itedpjyx Etaefx Al Njf