Used Straight Grinder for sale (3,600)

Condition: new, The HFS 60160 F NC, a robust Conventional Surface Grinder, is engineered to handle large and heavy workpieces with precision required for efficient surface grinding, lapping, or polishing. Its massive cross-bed design provides exceptional rigidity, enabling optimal weight distribution and a long table guidance for consistent performance. The machine features a large grinding spindle that is permanently lubricated, ensuring maximum grinding performance and reliability. Additionally, it is equipped with a powerful cooling system and flexible automatic or manual operation, making it suitable for sample production, repairs, and training. User-friendly Siemens Smart Line PLC control with a touchscreen allows for easy access to editable grinding cycles. The standard equipment includes essentials such as a magnetic clamping plate, electronic handwheel for precise positioning, and a fully enclosed workspace for enhanced safety. When looking for a reliable Conventional Surface Grinder, the HFS 60160 F NC by KNUTH stands ready to meet your machining needs. Request a quote today to experience the efficiency and precision of this exceptional grinding machine. Bwsdpeww T Tlsfx Aaqsw

Condition: excellent (used), Year of construction: 1999, Profile grinding machine Döbeli FSM 150, built in 1999 Bsdpfx Aaswarqbsqjww CNC profile grinder Control: Fanuc 18M Projection: Field of view: 300 x 200 mm Magnification: 10x, 20x, 50x Illumination: 12 V, 100 W Coolant unit tank capacity: 80 L Grinding head: rotation ±30°, inclination -15° Grinding stroke: Length: 78 mm Speed: 0-280 strokes/min Spindle motor: 1 HP Spindle speed: 4,000 rpm Grinding spindle wheel diameter: 150 mm Travel range: Profile width, CNC-axis X: 120 mm Profile depth, CNC-axis Y: 50 mm Linear axis :0.0001 mm Working table: Height adjustment: 80 mm Travel in workpiece height: 150 mm Max workpiece diameter: 200 mm.

Condition: reconditioned (used), Year of construction: 2017, operating hours: 2,710 h, functionality: fully functional, grinding length: 1,000 mm, grinding width: 600 mm, distance table to spindle center: 750 mm, table length: 900 mm, table load: 1,500 kg, type of input current: three-phase, table width: 600 mm, grinding wheel width: 50 mm, overall weight: 11,000 kg, grinding spindle motor power: 11,000 W, grinding wheel speed: 2,000 rpm, input voltage: 400 V, Equipment: documentation/manual, TECHNICAL CHARACTERISTICS: CNC control : FANUC series 32i-B Colour touch screen : 15 ["] W axis travel (longitudinal axis) : 1300 [mm] Min. Stroke speed W axis : 0.1 [mm/min] Max. Stroke speed W axis : 40000 [mm/min] Rapid traverse rate W axis : 40000 [mm/min] X axis travel (transverse movement) : 660 [mm] Min. Stroke speed X axis : 0.1 [mm/min] Max. Stroke speed X axis : 5000 [mm/min] Rapid traverse rate X axis : 5000 [mm/min] Resolution X axis : 0.0001 [mm] Stroke Y axis (vertical movement) : 750 [mm] Min. Stroke speed Y axis : 0.1 [mm/min] Max. Stroke speed Y axis : 500 [mm/min] Rapid traverse rate Y axis : 2000 [mm/min] Resolution Y axis : 0.0001 [mm] Table length : 900 [mm] Table width : 600 [mm] Max. distance spindle nose / table : 750 [mm] Max. load on table : 1500 [Kg] Grinding wheel min. speed : 300 [rpm] Grinding wheel max. speed : 2000 [rpm] Grinding spindle motor power : 11 [kW] Max. diameter grinding wheel : 405 [mm] Bwjdpowuk Inefx Aaqsw Max. grinding wheel width : 50 [mm] Grinding wheel bore : 127 [mm] Total power required : 29 [kVA] Weight : 11000 [Kg] EQUIPMENT / INCLUDED OPTIONS: x1 electro-magnetic chuck 900 x 600 [mm] x3 linear glass scales on the 3 linear axes x1 workpiece probe x1 paper tape filtration unit x1 oil chiller DAIKIN AKZ149-C x1 oil mist collector IFS type M 1600 x1 transformer The information on this page has been obtained by the best of our ability. Therefore, its accuracy can not be guaranteed

Condition: used, Year of construction: 1986, Pressure total: 500 ton Stroke: 1100 mm Daylight: 1500 mm Table surface area : 2000 x 1250 mm Slide area: 2000 x 1250 mm Die cushion capacity in table: 160 ton Die cushion stroke: 300 mm Approach speed: 650 mm / sec Required power: 55 kW Weight of machine approx.: 50 ton Bodpfx Aajuqdqloqjww Standard configuration The press was completely overhauled mechanically, hydraulically and electrically in 2008.

Condition: excellent (used), Year of construction: 2009, operating hours: 100 h, functionality: fully functional, machine/vehicle number: SKU 102781, overall weight: 1,300 kg, power: 4 kW (5.44 HP), space requirement width: 1,350 mm, space requirement length: 1,520 mm, space requirement height: 1,400 mm, Equipment: rotational speed infinitely variable, The special design of the Multi Grind makes it possible to combine the functions of cylindrical, surface, and tool grinding in a single machine. During external cylindrical grinding, the workpiece can be clamped on one side or supported between centers in the robust tailstock. An internal grinding attachment can also be mounted on the headstock, and even light surface grinding tasks are possible with this model. In tool grinding operations, the Multi Grind allows for precise sharpening of the cutting edges on a wide variety of tools – making it particularly versatile in its application. Bwodpfxsxqgi De Aaqsw - External and internal cylindrical grinding - Surface grinding - Tool grinding - Hydraulic table feed - Extensive accessories

Condition: used, Year of construction: 1986, functionality: fully functional, machine/vehicle number: 4/0001/09472, MACHINE SPECIFICATION Distance between centres 635mm Centre height 165mm Swing Swing over bed 335mm Swing over cross slide 209mm Spindle Bored to pass 40mm dia Nose D1-4 Camlock Morse taper in nose N0 3 Width of bedways 231mm Travel Total travel of cross slide 209mm Total travel of top slide 95mm Total travel of tailstock barrel 146mm Speeds Spindle speeds (16) 22-1800rpm Spindle motor 2.25kW MACHINE SPECIFICATION Cont’d Whitworth threads (45) 2-72tpi Diametral threads (21) 8-44 Metric pitches (39) 0.2-14.0mm Module pitches (18) 0.3-3.5 Feeds Sliding feeds 0.001-0.040 ipr/spindle Surfacing feeds 0.0005-0.020 ipr/spindle Tailstock Approx weight 800Kg Bodpfjxn Iv Tsx Aaqjww Machine in Imperial execution MACHINE EQUIPPED WITH 3 jaw chuck Quick change toolpost and 6 off toolholders Ainjest high speed screwcutting attachment Single bedstop 5 Position turret bedstop Apron dial Chuck guard Coolant system Rear splashguard

Condition: new, The KNUTH Multi-Grind is a versatile tool grinder within the Tool Grinders category, designed to efficiently combine cylindrical, flat, and tool grinding in one machine. Its exceptional construction allows for external cylindrical grinding with workpieces either clamped on one side or supported by a robust tailstock. Additionally, the Multi-Grind includes an internal grinding device and is capable of light surface grinding tasks. This advanced machine features a custom three-point bearing for the grinding spindle, ensuring minimal temperature effects and consistent grinding quality. With hydraulic table feed capabilities and speeds of up to 300 min-1, the Multi-Grind can accommodate a variety of tools and applications. It's equipped with a central lubrication system and sturdy cast-iron construction to minimize vibration. The machine's extensive standard equipment includes a coolant system, die grinders, and various accessories. Experience precision and performance with the KNUTH Multi-Grind—request a quote today to enhance your grinding operations in the Tool Grinders product group. Bwedpfx Aaouyid Roqow

Condition: refurbished (used), Year of construction: 2015, operating hours: 6,840 h, functionality: fully functional, grinding length: 1,600 mm, grinding width: 600 mm, feed length X-axis: 1,700 mm, feed rate X-axis: 30 m/min, feed rate Y-axis: 6 m/min, feed rate Z-axis: 6 m/min, grinding wheel diameter: 400 mm, distance table to spindle center: 950 mm, table length: 1,600 mm, table width: 600 mm, grinding wheel width: 30 mm, overall weight: 8,000 kg, grinding spindle motor power: 15,000 W, Equipment: documentation/manual, rotational speed infinitely variable, CNC surface grinder BLOHM Planomat 616 HP TECHNICAL CHARACTERISTICS : Year of manufacturing : 2015 CNC control : SIEMENS 840D SL Maximum grinding lenght x width : 1600 x 600 [mm] Stroke X axis (table movement) : 1700 [mm] Min. Stroke speed X axis : 30 [mm/min] Max. Stroke speed X axis : 30000 [mm/min] Resolution X axis : 0.001 [mm] Stroke Y axis (vertical movement) : 800 [mm] Min. Stroke speed Y axis : 4 [mm/min] Max. Stroke speed Y axis : 6000 [mm/min] Resolution Y axis : 0.001 [mm] Course axe Z (transverse movement) : 560 [mm] Min. Stroke speed Z axis : 4 [mm/min] Max. Stroke speed Z axis : 6000 [mm/min] Resolution Z axis : 0.001 [mm] Min. distance spindle nose / table : 150 [mm] Max. distance spindle nose / table : 950 [mm] Grinding spindle motor power : 15 [kW] Max. diameter grinding wheel : 400 [mm] Max. grinding wheel width : 30 [mm] Grinding wheel bore : 127 [mm] Dimensions of magnetic plate : 1600 x 600 [mm] Machine dimensions : 5450 x 3560 x 2800 [mm] Supply voltage : 400 [V] Number of hours under power: 6840 [h] Weight : 8000 [Kg] EQUIPMENT INCLUDED: Bjdpewu R Iuefx Aaqoww x1 coolant tank + paper filtration system DGS type SBF150/650 x1 oil mist extractor (2000 m3/h) SARA type UC 2 SD/S3 x1 1600*600 [mm] electromagnetic clamping plate SAV type B-243.70 - 1600 x 600 - 13 x1 lifting dressing device for peripheral, side and profile dressing x5 grinding wheel flanges x15 grinding wheels Ø400 [mm] x1 wheel balancing bench x1 set of manuals + CD Machine visible under power in our premises by appointment. Price on request, loading on truck included. Possibility of shipping Worldwide. The information on this page has been obtained by the best of our ability. Therefore, its accuracy can not be guaranteed. Machine similar to the brands okamoto , jones shipman , jung , favretto , studer see also cylindrical grinder , lathe , machining centre , milling machine

Condition: used, Year of construction: 2005, Pressure total: 400 ton Ram stroke: 500 mm Slide adjustment: 350 mm Daylight: 1250 mm Bwsdswnn Rtspfx Aaqew Table surface area : 2500 x 1500 mm Slide area: 2500 x 1500 mm Die cushion capacity in table: 80 ton Die cushion stroke: 250 mm Number of strokes: 15 - 30 s.p.m. Die weight at the ram max.: 4000 kg Required power: 70 kW Height over floor approx.: 8000 mm Weight of machine approx.: 150 ton Standard configuration 2 cushion cylinder 2 pads

Condition: new, The FSM 14 S Tool Grinder by KNUTH is a robust machine designed specifically for the precise and cost-effective grinding of HSS and carbide milling cutters, ranging from 4 to 14 mm in diameter. This handy milling cutter grinder series stands out for its user-friendly operation, making it an ideal choice for any tool crib, where efficient tool maintenance is essential. The FSM 14 S features the capability to grind 2, 3, and even 4-blade cutters, with an additional station available for outer spiral cutting edge grinding. Included in the package are collets tailored for common cutter diameters—4, 6, 8, 10, 12, and 14 mm—along with high-quality grinding wheels that enhance your workflow. This machine ensures rapid tooling and quick setup, enabling you to maintain your tools effectively. Invest in the FSM 14 S Tool Grinder today and elevate your tool sharpening capabilities. Request a quote for this reliable Tool Grinder and ensure your cutting tools are always ready for use. Bwodpsp Dtx Usfx Aaqsw

Condition: reconditioned (used), Year of construction: 2014, functionality: fully functional, grinding length: 800 mm, grinding width: 400 mm, grinding wheel diameter: 355 mm, distance table to spindle center: 500 mm, table load: 1,000 kg, type of input current: three-phase, overall weight: 5,000 kg, grinding spindle motor power: 7,500 W, grinding wheel speed: 2,500 rpm, input voltage: 400 V, Equipment: documentation/manual, TECHNICAL CHARACTERISTICS: CNC control : FANUC series 32i-B W axis travel (longitudinal axis) : 1000 [mm] Min stroke speed W axis : 0.1 [mm/min] Max stroke speed W axis : 40000 [mm/min] Rapid traverse rate W axis : 40000 [mm/min] X axis travel (transverse movement) : 450 [mm] Min stroke speed X axis : 0.1 [mm/min] Max stroke speed X axis : 5000 [mm/min] Rapid traverse rate X axis : 5000 [mm/min] Resolution X axis : 0.0001 [mm] Stroke Y axis (vertical movement) : 500 [mm] Min stroke speed Y axis : 0.1 [mm/min] Max stroke speed Y axis : 500 [mm/min] Rapid traverse rate Y axis : 2000 [mm/min] Resolution Y axis : 0.0001 [mm] Table length : 600 [mm] Table width : 400 [mm] Max distance spindle nose / table : 500 [mm] Max load on table : 1000 [Kg] Grinding wheel min speed : 300 [rpm] Grinding wheel max speed : 2500 [rpm] Grinding spindle motor power : 7.5 [kW] Max diameter grinding wheel : 355 [mm] Max grinding wheel width : 50 [mm] Grinding wheel bore : 127 [mm] Total power required : 23 [kVA] Weight : 5000 [Kg] EQUIPMENT / INCLUDED OPTIONS: x1 electro-magnetic chuck 600 x 400 [mm] x3 glass linear scales on the 3 linear axes x1 workpiece probe x1 paper filtration unit Bwjdpfxowulg Ee Aaqsw x1 oil chiller DAIKIN AKZ149M133 x1 oil mist collector IFS type IFMC 1100 x1 transformer The information on this page has been obtained by the best of our ability. Therefore, its accuracy can not be guaranteed

Condition: used, Year of construction: 2002, machine/vehicle number: 10857, Pressure total: 315 ton Stroke: 1100 mm Daylight: 2200 mm Table surface area : 2500 x 1000 mm Slide area: 2500 x 1000 mm Bjdpfx Aaevmfzbsqjww Die weight at the ram max.: 6000 kg Approach speed: 600 mm / sec Working speed: 32 - 230 mm / sec Return speed: 600 mm / sec Required power: 158 kW Weight of machine approx.: 44 ton Height over floor approx.: 6175 mm Automation

Condition: new, The Servogrind® RSM 1000 NC is a state-of-the-art Conventional Cylindrical Grinder designed for precision machining of long and heavy workpieces, setting a new standard in the Grinding Machines category. This machine features a modern servo motor drive that enhances both dynamics and efficiency, ensuring exceptional precision. Equipped with a heavy machine bed and precision-ground guides, it effectively minimizes vibration, providing consistent and high-quality results in both single part and small batch production. The NC control with touchscreen interface simplifies operation without the need for programming knowledge, while features like the swiveling table and work spindle add flexibility for internal and external grinding tasks. Standard equipment also includes a 3-jaw chuck, an electronic handwheel, and an automatic central lubrication system, which collectively contribute to reduced maintenance time and enhanced operational efficiency. With its robust construction and advanced capabilities, the Servogrind® RSM 1000 NC not only facilitates efficient machining but also ensures longevity and reliability. To learn more or to buy now, please request a quote for the Servogrind® RSM 1000 NC today. Bodpfx Aajxhdwmjqsww

Condition: used, Year of construction: 1996, machine/vehicle number: 14.194, Pressure total: 80 - 800 ton Ram stroke: 1600 mm Free frontal opening L-R: 2850 mm Free lateral opening F-B: 1000 mm Daylight: 1900 mm Table surface area : 2800 x 2000 mm Slide area: 2800 x 2000 mm Die cushion capacity in table: 32 - 320 ton Die cushion stroke: 400 mm Die cushion pad area: 2500 x 1700 mm Bwjdpfx Aeu Saaaoaqow Approach speed: 400 mm / sec Working speed: 5 -42,7 mm / sec Return speed: 420 mm / sec Required power: 246 kW Height over floor approx.: 7785 mm Weight of machine approx.: 100 ton No. of moving bolster: 1 pcs.

Condition: new, The RSM 1500 C, a precision cylindrical grinder from KNUTH, is designed for long and heavier workpieces within the Conventional Cylindrical Grinders category. This robust machine features a large machine bed that supports workpieces up to 2000 mm in length and 320 mm in diameter, ensuring maximum accuracy and stability. Wide, precision-ground guideways contribute to reliable performance, while the grinding spindle with hydrostatic bearings guarantees high precision and surface quality. The powerful motor allows for continuous operation, making it ideal for both individual parts and small series production. Operators can benefit from adjustable dwell times and precise micro-feed control, enhancing the grinding process. With an integrated internal grinding device, the RSM 1500 C offers exceptional flexibility. If you're looking for a reliable solution for cylindrical grinding, request a quote or buy now to experience the efficiency of this powerful Conventional Cylindrical Grinder from KNUTH. Bjdpfxsu E N Dno Aaqsww

Condition: used, Year of construction: 1989, Pressure total: 1400 ton Stroke: 950 mm Daylight: 2000 mm Bjdpfx Aajuqdi Ujqsww Table surface area : 3600 x 2500 mm Slide area: 3600 x 2500 mm Die cushion capacity in table: 400 ton Die cushion stroke: 500 mm Die cushion pad area: 3060 x 1860 mm Approach speed: 400 mm / sec Working speed: 40 / 80 mm / sec Return speed: 400 mm / sec Oil volume: 5000 l Required power: 450 kW Weight of machine approx.: 240 ton Standard configuration with hydraulic tool clamps on the ram

Condition: new, The ABS 380 L is a cutting-edge horizontal straight cutting bandsaw from KNUTH, designed for high-performance sawing in the Auto Straight Bandsaw category. This fully automatic machine features a robust dual column frame that ensures superior stability, making it ideal for precisely straight sawing of large and heavy workpieces. The ABS 380 L offers a torsionally rigid steel construction complemented by high-quality linear guides, ensuring durability and accuracy during operation. With an advanced hydraulic saw frame feed design, operators can infinitely adjust the feed speed and cutting pressure for various sawing tasks. Additionally, the hydraulic workpiece clamping and optical detection of workpiece height enhance efficiency by automating crucial processes, substantially reducing operator workload. Standard equipment includes a saw-band, workpiece counter, and a coolant system, providing everything needed for reliable operation. For those seeking robust performance in horizontal straight cutting bandsaws, the ABS 380 L is an excellent choice. You can order online today and experience the exceptional capabilities of the Auto Straight Bandsaw. Bwjdpfx Aou E Imhsaqow

Condition: used, Pressure total: 500 ton Ram stroke: 500 mm Slide adjustment: 400 mm Daylight: 1350 mm Table surface area : 3000 x 1700 mm Slide area: 3000 x 1700 mm Die cushion capacity in table: 80 ton Bsdpfjwnnanox Aaqoww Die cushion stroke: 250 mm Number of strokes: 20 s.p.m. Required power: 75 kW Height over floor approx.: 8000 mm Weight of machine approx.: 160 ton Standard configuration 2 cushion cylinder 1 pad

Condition: new, The RSM 1000 C is a precision cylindrical grinder in the Conventional Cylindrical Grinders category, designed by KNUTH for processing long and heavy workpieces. This exceptional machine features a robust design with a large, heavy machine bed that accommodates workpieces up to 2000 mm in length and 320 mm in diameter, ensuring maximum accuracy and supporting high weights. Equipped with wide, precision-ground guideways, this grinder delivers outstanding surface quality thanks to its hydrostatic bearings, while the powerful grinding spindle motor is optimally designed for continuous operation. The RSM 1000 C includes an internal grinding device and a swiveling headstock which allows for conical grinding of short parts, enhancing its versatility for both individual and small series production. Its extensive standard equipment package, such as a 3-axis position indicator and a coolant system, adds to its appeal. For any needs in the Conventional Cylindrical Grinders category, request a quote today to explore how the RSM 1000 C can enhance your grinding operations. Bsdpeuy Ia Rsfx Aaqjww

Condition: used, Year of construction: 2005, Pressure total: 400 ton Ram stroke: 500 mm Slide adjustment: 350 mm Daylight: 1250 mm Table surface area : 2500 x 1500 mm Slide area: 2500 x 1500 mm Number of strokes: 15 - 30 s.p.m. Bwjdpfjwnpavex Aaqjw Die weight at the ram max.: 4000 kg Required power: 70 kW Height over floor approx.: 8000 mm Weight of machine approx.: 150 ton Standard configuration without cushion

Condition: new, The ABS 460 L is a cutting-edge horizontal straight cutting bandsaw from KNUTH, designed for high-performance in the Auto Straight Bandsaw category. Engineered with a torsionally rigid frame composed of robust steel and high-quality linear guides, this machine guarantees precise straight sawing of large, heavy workpieces. Its advanced hydraulic saw frame feed and optical detection of workpiece height automate tasks to optimize efficiency, reducing the operator's workload. The effective material feed system, equipped with hardened guide rollers, ensures high repeatability and dimensional accuracy without the need for complex electronics. Additionally, features such as hydraulic clamping and an easy-to-use central control panel put you in charge of speed settings effortlessly. With a cutting capacity of 460 mm for round materials and 470x460 mm for flat items, this robust machine is your reliable partner for demanding sawing tasks. Request a quote today to discover how the ABS 460 L can elevate your cutting process within the Horizontal Straight Cutting Bandsaws product group. Bwodpfx Aeq R Rlljaqew

Condition: used, Year of construction: 2006, machine/vehicle number: 18282, Pressure total: 140 ton Stroke: 800 mm Daylight: 1.004 mm Free frontal opening L-R: 2.060 mm Table surface area : 2.000 x 520 mm Slide area: 2.040 x 520 mm Bjdpfxeuqd Nuo Aaqeww Working speed: 4 -20 mm / sec Rapid travel: 135 mm / sec Return speed: 120 mm / sec Weight of machine approx.: 14 ton Height over floor approx.: 4.810 mm Oil volume: 700 l

Condition: new, The HFS 4080 F Advance is a remarkable Conventional Surface Grinder from KNUTH, designed to elevate precision machining within the realm of Grinding Machines. This advanced surface grinding machine is built on a robust cast-iron frame, ensuring superior rigidity and quality while featuring precision guideways for excellent machining outcomes. Enhanced with Siemens technology, including a user-friendly touchscreen, the HFS 4080 F Advance offers intuitive programming and automatic processing of roughing and finishing parameters, perfect for users seeking more than conventional solutions without venturing into full CNC systems. With extensive standard equipment such as a large magnetic clamping plate, automatic central lubrication, and a powerful coolant system, this grinder guarantees exceptional efficiency and minimal maintenance. The preloaded precision bearings and high-quality servo motors ensure maximum reliability and repeatability, making it an ideal choice for demanding manufacturing environments. For those interested in enhancing their operations, you can request a quote for the HFS 4080 F Advance today and experience the benefits of a top-tier Conventional Surface Grinder. Bsdpsq I Nfpefx Aaqsww

Condition: used, Year of construction: 2006, machine/vehicle number: 18282, Pressure total: 140 ton Stroke: 800 mm Daylight: 1.004 mm Free frontal opening L-R: 2.060 mm Table surface area : 2.000 x 520 mm Slide area: 2.040 x 520 mm Working speed: 4 -20 mm / sec Rapid travel: 135 mm / sec Return speed: 120 mm / sec Weight of machine approx.: 14 ton Bodpfx Aaeuqd S Ajqeww Height over floor approx.: 4.810 mm Oil volume: 700 l

Condition: new, The RSM 800 is a precision Conventional Cylindrical Grinder, designed by KNUTH to deliver exceptional grinding performance. Built on a rigid machine frame made of premium cast iron, the RSM series features long support guideways that enhance stability during operation. The machine is equipped with a hydraulic linear feed that offers infinitely variable micro-feeding, ensuring precise adjustments. You will appreciate the swiveling table for taper grinding, while the hydraulic adjustment of the headstock simplifies setup and workpiece exchanges, ultimately minimizing downtime. With a grinding diameter of 8 to 200 mm and a grinding length of 800 mm, this robust machine is engineered to meet diverse application needs. Additionally, it comes standard with essential equipment such as a 2-axis position indicator and internal grinding accessories. For a powerful and reliable Conventional Cylindrical Grinder, consider the RSM 800. Request a quote today and explore how this machine can enhance your grinding capabilities in the realm of Grinding Machines. Bjdpfxencdx Eo Aaqoww