Used Pneumatic Table for sale (22,605)

Condition: new, Year of construction: 2023, total height: 860 mm, total length: 4,000 mm, total width: 2,000 mm, overall weight: 2,400 kg, Manufacturer: GERD WOLFF Technical details: - Length 4000 mm - Width 2000 mm - Height 200 mm - Weight 2400 kg - Hole diameter 28 mm - Hole spacing 100 mm Advantages and properties - 3-day gas nitriding process - Increased corrosion resistance - Protection against weld spatter adhesion Itsdpfx Adstrlcvodjb - Maximum load - Increased fatigue strength - Increase in fatigue strength - Fine scaling - Reinforcement through welded seams and ribs on the underside - Optimum working height from 820-865 mm - 8x height-adjustable legs - With matching accessory set (optional) Our welding tables are manufactured with HT 300 cast quality and nitrided in one piece after nitrided in one piece after mechanical processing. They also have precise fine scaling, which is engraved using laser technology. engraved using laser technology. To ensure appropriate stability, our welding tables are reinforced on the underside reinforced on the underside by means of weld seams and ribs. (See illustrations) In addition, they undergo a 3-day gas nitriding process which, among other things corrosion resistance, fatigue strength and vibration resistance of the tables. tables. All our tables are equipped with adjustable legs. The minimum adjustment range is 620 mm, the maximum 665 mm. This enables a variable working height from 820 to 865 mm Manufacturer: GERD WOLFF Website: Technical Details: • Length 1000 mm • Width 1000 mm • Height 200 mm • Weight 300 kg • Hole diameter 28 mm • Hole spacing 100 mm Advantages and Features: • 3-day gas nitriding process • Increased corrosion resistance • Weld spatter adhesion protection • Maximum load capacity • Enhanced fatigue strength • Improved vibration resistance • Fine scale engraving • Reinforcement with welded seams and ribs on the underside • Optimal working height of 820-865 mm • 4 height-adjustable support legs • Available with a matching accessory set (optional) Our welding tables are manufactured using HT 300 cast iron and are nitrided as a whole after mechanical processing. Furthermore, they feature precise fine scale engraving using laser technology. To ensure adequate stability, our welding tables are reinforced with welded seams and ribs on the underside (see illustrations). Additionally, they undergo a 3-day gas nitriding process, enhancing their corrosion resistance, fatigue strength, and vibration resistance, among other factors. All our tables come with adjustable legs. The minimum height adjustment range is 620 mm, while the maximum is 665 mm, allowing for a variable working height of 820 to 865 mm. Additional available dimensions: • 1000 x 1000 x 200 • 2000 x 1000 x 200 • 1200 x 1200 x 200 • 1500 x 1000 x 200 • 1500 x 1500 x 200 • 1500 x 2000 x 200 • 2000 x 3000 x 200 • 3000 x 1500 x 200 • 3000 x 2000 x 200 • 4000 x 2000 x 200 • 2400 x 1200 x 200 Please note that the images are not to scale and are for illustrative purposes only. Our welding tables are produced for our distribution brand "GERD WOLFF Maschinenfabrik" by a reputable manufacturer. 3D Welding Table - 3D Clamping Fixtures - 3D Precision Welding Table

Condition: new, Year of construction: 2024, total height: 860 mm, total length: 2,000 mm, total width: 1,000 mm, overall weight: 650 kg, height adjustment type: mechanical, Manufacturer: GERD WOLFF Technical Details: • Length 2000 mm • Width 1000 mm • Height 200 mm Iodpfevbbqzsx Addjtb • Weight 650 kg • Hole diameter 28 mm • Hole spacing 100 mm • Plate thickness: 25mm Advantages and Features: • 3-day gas nitriding process • Increased corrosion resistance • Weld spatter adhesion protection • Maximum load capacity • Enhanced fatigue strength • Improved vibration resistance • Fine scale engraving • Reinforcement with welded seams and ribs on the underside • Optimal working height of 820-865 mm • 4 height-adjustable support legs • Available with a matching accessory set (optional) Our welding tables are manufactured using HT 300 cast iron and are nitrided as a whole after mechanical processing. Furthermore, they feature precise fine scale engraving using laser technology. To ensure adequate stability, our welding tables are reinforced with welded seams and ribs on the underside (see illustrations). Additionally, they undergo a 3-day gas nitriding process, enhancing their corrosion resistance, fatigue strength, and vibration resistance, among other factors. All our tables come with adjustable legs. The minimum height adjustment range is 620 mm, while the maximum is 665 mm, allowing for a variable working height of 820 to 865 mm. Additional available dimensions: • 1000 x 1000 x 200 • 1200 x 1200 x 200 • 1500 x 1000 x 200 • 1500 x 1500 x 200 • 1500 x 2000 x 200 • 2000 x 3000 x 200 • 3000 x 1500 x 200 • 3000 x 2000 x 200 • 4000 x 2000 x 200 • 2400 x 1200 x 200 Please note that the images are not to scale and are for illustrative purposes only. Our welding tables are produced for our distribution brand "GERD WOLFF Maschinenfabrik" by a reputable manufacturer. 3D Welding Table - 3D Clamping Fixtures - 3D Precision Welding Table

Year of construction: 1999, condition: used, table length mm table width mm table load t Itedpfx Aogxqvzsddob plate width 2980 mm plate depth 3000 mm plate height 1400 mm total power requirement 11 kW weight of the machine ca. t required space m

Condition: new, Year of construction: 2025, table length 4000 mm table width 2000 mm table height 200 mm weight 2400 kg Manufacturer: GERD WOLFF Technical Details: • Length 4000 mm • Width 2000 mm • Height 200 mm • Weight 2400 kg • Hole diameter 28 mm • Hole spacing 100 mm • Plate thickness: 25mm Advantages and Features: • 3-day gas nitriding process • Increased corrosion resistance • Weld spatter adhesion protection • Maximum load capacity Itsdpfxsuia I Nj Addsb • Enhanced fatigue strength • Improved vibration resistance • Fine scale engraving • Reinforcement with welded seams and ribs on the underside • Optimal working height of 820-865 mm • 8 height-adjustable support legs • Available with a matching accessory set (optional) Our welding tables are manufactured using HT 300 cast iron and are nitrided as a whole after mechanical processing. Furthermore, they feature precise fine scale engraving using laser technology. To ensure adequate stability, our welding tables are reinforced with welded seams and ribs on the underside (see illustrations). Additionally, they undergo a 3-day gas nitriding process, enhancing their corrosion resistance, fatigue strength, and vibration resistance, among other factors. All our tables come with adjustable legs. The minimum height adjustment range is 620 mm, while the maximum is 665 mm, allowing for a variable working height of 820 to 865 mm. Additional available dimensions: • 1000 x 1000 x 200 • 2000 x 1000 x 200 • 1200 x 1200 x 200 • 1500 x 1000 x 200 • 1500 x 1500 x 200 • 1500 x 2000 x 200 • 2000 x 3000 x 200 • 3000 x 1500 x 200 • 3000 x 2000 x 200 • 4000 x 2000 x 200 • 2400 x 1200 x 200 Please note that the images are not to scale and are for illustrative purposes only. Our welding tables are produced for our distribution brand "GERD WOLFF Maschinenfabrik" by a reputable manufacturer. 3D Welding Table - 3D Clamping Fixtures - 3D Precision Welding Table

Condition: new, Year of construction: 2025, table length 3000 mm table width 2000 mm table height 200 mm weight 1700 kg Manufacturer: GERD WOLFF Technical Details: • Length 2000 mm • Width 3000 mm • Height 200 mm • Weight 1700 kg • Hole diameter 28 mm • Hole spacing 100 mm • Plate thickness: 25mm Advantages and Features: • 3-day gas nitriding process • Increased corrosion resistance • Weld spatter adhesion protection • Maximum load capacity • Enhanced fatigue strength • Improved vibration resistance • Fine scale engraving • Reinforcement with welded seams and ribs on the underside • Optimal working height of 820-865 mm • 8 height-adjustable support legs • Available with a matching accessory set (optional) • Plate thickness: 25mm Our welding tables are manufactured using HT 300 cast iron and are nitrided as a whole after mechanical processing. Furthermore, they feature precise fine scale engraving using laser technology. To ensure adequate stability, our welding tables are reinforced with welded seams and ribs on the underside (see illustrations). Additionally, they undergo a 3-day gas nitriding process, enhancing their corrosion resistance, fatigue strength, and vibration resistance, among other factors. All our tables come with adjustable legs. The minimum height adjustment range is 620 mm, while the maximum is 665 mm, allowing for a variable working height of 820 to 865 mm. Additional available dimensions: • 1000 x 1000 x 200 • 2000 x 1000 x 200 • 1200 x 1200 x 200 • 1500 x 1000 x 200 • 1500 x 1500 x 200 • 1500 x 2000 x 200 • 2000 x 3000 x 200 • 3000 x 1500 x 200 • 3000 x 2000 x 200 • 4000 x 2000 x 200 • 2400 x 1200 x 200 Please note that the images are not to scale and are for illustrative purposes Itjdpfx Adsuia Ntsdjb only. Our welding tables are produced for our distribution brand "GERD WOLFF Maschinenfabrik" by a reputable manufacturer. 3D Welding Table - 3D Clamping Fixtures - 3D Precision Welding Table

Condition: new, Year of construction: 2025, number 40-teilig weight 47 kg condition Neu FIX KIT 40 - The Comprehensive Solution Set for Welding Tables Stock Number: FIX40 Weight: 47 KG Shipping: Pallet Shipping (not included in the price)# CONTENTS 2x Clamping and Squaring Angle 175 x 50 x 175 mm 2x Clamping and Squaring Angle 275 x 50 x 175 mm 4x Stop 100 x 50 x 25 mm 4x Sliding Stop 150 x 50 x 25 mm 4x Large Universal Stop 225 x 50 x 25 mm 2x Clamping and Squaring Angle 75 x 50 x 75 mm 2x Prism D58 x 90° 58 x 50 (H) - 90° 4x 180° Clamp 300 x 300 mm 2x 45° Clamp 300 x 300 mm 1x Round Brush 1x Grounding Device 12x Quick-Release Bolt 28 x 75 mm Clamping range between 70-75 mm. Also available individually and in a 50 mm version. Specifically designed for welding tables, the FIX KIT 40 emerges as a comprehensive 40-piece fixture kit. With a precise bore diameter of 28 mm, it ensures seamless integration and adaptability. Not only is this set robust and durable, but it's also perfectly tailored to the requirements of welding tables. The FIX KIT 40 offers a tailored solution for customizing your tool equipment. The included modules are carefully selected to create clamps and fixtures with the utmost precision and efficiency. This allows you to optimize your workspace according to your specific needs. Itodpfsw T Uzhex Addob In a world where adaptability and precision are paramount, the FIX KIT 40 sets new standards. It's not just a kit; it's a key tool that aids you in making your work processes more effective and efficient.

Condition: new, Year of construction: 2025, diameter 28 mm length 50 mm clamping range 45-50 mm The price is exclusive of statutory VAT. Also available in D28 x 75 mm (clamping range 70–75 mm). Clamping range: 45–50 mm Type: Ball Lock Pin 50 mm Diameter: 28 ± 0.02 mm Material: 45# steel Hardness: HRC28–32 Surface roughness: Ra 0.8 µm GERD WOLFF ball lock pins are specialized fastening components designed for integration into a wide range of welding table systems and setups. Their main function is the efficient and precise positioning and securing of workpieces. These pins are compatible with welding tables from all manufacturers that feature 28 mm bore holes. The unique ball-lock design enables flexible alignment of workpieces at various angles and positions. Thanks to their high-quality manufacturing and robust construction, GERD WOLFF ball lock pins provide reliable holding force throughout the entire welding process. These pins allow for easy handling, fast clamping, and release of workpieces — without the need for additional tools. GERD WOLFF stands for quality and precision in welding technology. These ball lock pins are engineered to meet the high demands of professional welding applications. Quick release locking pins, quick lock pins, quick releases, quick installation pin, metal horizontal quick release, working pin, quick release locking pin, quick latch pin, locking quick release pins. Itedpfxow Td Auo Addjb

Condition: new, Year of construction: 2025, table length 2400 mm table width 1200 mm table height 200 mm material thickness 25 mm weight 920 kg Manufacturer: GERD WOLFF Technical Details: • Length 2400 mm • Width 1200 mm • Height 200 mm • Weight 920 kg • Hole diameter 28 mm • Hole spacing 100 mm • Plate thickness: 25mm Advantages and Features: • 3-day gas nitriding process • Increased corrosion resistance • Weld spatter adhesion protection • Maximum load capacity • Enhanced fatigue strength Itodpfsvvx Hpex Addob • Improved vibration resistance • Fine scale engraving • Reinforcement with welded seams and ribs on the underside • Optimal working height of 820-865 mm • 6 height-adjustable support legs • Available with a matching accessory set (optional) Our welding tables are manufactured using HT 300 cast iron and are nitrided as a whole after mechanical processing. Furthermore, they feature precise fine scale engraving using laser technology. To ensure adequate stability, our welding tables are reinforced with welded seams and ribs on the underside (see illustrations). Additionally, they undergo a 3-day gas nitriding process, enhancing their corrosion resistance, fatigue strength, and vibration resistance, among other factors. All our tables come with adjustable legs. The minimum height adjustment range is 620 mm, while the maximum is 665 mm, allowing for a variable working height of 820 to 865 mm. Additional available dimensions: • 1000 x 1000 x 200 • 2000 x 1000 x 200 • 1200 x 1200 x 200 • 1500 x 1000 x 200 • 1500 x 1500 x 200 • 1500 x 2000 x 200 • 2000 x 3000 x 200 • 3000 x 1500 x 200 • 3000 x 2000 x 200 • 4000 x 2000 x 200 Please note that the images are not to scale and are for illustrative purposes only. Our welding tables are produced for our distribution brand "GERD WOLFF Maschinenfabrik" by a reputable manufacturer. 3D Welding Table - 3D Clamping Fixtures - 3D Precision Welding Table

Condition: new, Year of construction: 2025, table length 1000 mm table width 2000 mm table height 200 mm weight 650 kg Manufacturer: GERD WOLFF Technical Details: • Length 2000 mm • Width 1000 mm • Height 200 mm • Weight 650 kg • Hole diameter 28 mm • Hole spacing 100 mm • Plate thickness: 25mm Advantages and Features: • 3-day gas nitriding process Iedpouia Naofx Addstb • Increased corrosion resistance • Weld spatter adhesion protection • Maximum load capacity • Enhanced fatigue strength • Improved vibration resistance • Fine scale engraving • Reinforcement with welded seams and ribs on the underside • Optimal working height of 820-865 mm • 4 height-adjustable support legs • Available with a matching accessory set (optional) Our welding tables are manufactured using HT 300 cast iron and are nitrided as a whole after mechanical processing. Furthermore, they feature precise fine scale engraving using laser technology. To ensure adequate stability, our welding tables are reinforced with welded seams and ribs on the underside (see illustrations). Additionally, they undergo a 3-day gas nitriding process, enhancing their corrosion resistance, fatigue strength, and vibration resistance, among other factors. All our tables come with adjustable legs. The minimum height adjustment range is 620 mm, while the maximum is 665 mm, allowing for a variable working height of 820 to 865 mm. Additional available dimensions: • 1000 x 1000 x 200 • 2000 x 1000 x 200 • 1200 x 1200 x 200 • 1500 x 1000 x 200 • 1500 x 1500 x 200 • 1500 x 2000 x 200 • 2000 x 3000 x 200 • 3000 x 1500 x 200 • 3000 x 2000 x 200 • 4000 x 2000 x 200 • 2400 x 1200 x 200 Please note that the images are not to scale and are for illustrative purposes only. Our welding tables are produced for our distribution brand "GERD WOLFF Maschinenfabrik" by a reputable manufacturer. 3D Welding Table - 3D Clamping Fixtures - 3D Precision Welding Table

Condition: new, Year of construction: 2025, table length 3000 mm table width 1500 mm table height 200 mm weight 1500 kg Manufacturer: GERD WOLFF Technical Details: • Length 3000 mm • Width 1500 mm • Height 200 mm • Weight 1500 kg • Hole diameter 28 mm • Hole spacing 100 mm • Plate thickness: 25mm Advantages and Features: • 3-day gas nitriding process Iodsuia Nmopfx Addotb • Increased corrosion resistance • Weld spatter adhesion protection • Maximum load capacity • Enhanced fatigue strength • Improved vibration resistance • Fine scale engraving • Reinforcement with welded seams and ribs on the underside • Optimal working height of 820-865 mm • 8 height-adjustable support legs • Available with a matching accessory set (optional) Our welding tables are manufactured using HT 300 cast iron and are nitrided as a whole after mechanical processing. Furthermore, they feature precise fine scale engraving using laser technology. To ensure adequate stability, our welding tables are reinforced with welded seams and ribs on the underside (see illustrations). Additionally, they undergo a 3-day gas nitriding process, enhancing their corrosion resistance, fatigue strength, and vibration resistance, among other factors. All our tables come with adjustable legs. The minimum height adjustment range is 620 mm, while the maximum is 665 mm, allowing for a variable working height of 820 to 865 mm. Additional available dimensions: • 1000 x 1000 x 200 • 2000 x 1000 x 200 • 1200 x 1200 x 200 • 1500 x 1000 x 200 • 1500 x 1500 x 200 • 1500 x 2000 x 200 • 2000 x 3000 x 200 • 3000 x 1500 x 200 • 3000 x 2000 x 200 • 4000 x 2000 x 200 Please note that the images are not to scale and are for illustrative purposes only. Our welding tables are produced for our distribution brand "GERD WOLFF Maschinenfabrik" by a reputable manufacturer. 3D Welding Table - 3D Clamping Fixtures - 3D Precision Welding Table

Condition: new, Year of construction: 2024, table length 1000 mm table width 1000 mm table height 200 mm weight 300 kg Our welding tables are manufactured with HT 300 casting quality. All welding tables are also available in a nitrided version. • Plate thickness: 25mm Iedouia N Tspfx Addjtb All our tables are equipped with adjustable legs. The minimum adjustment range is 620 mm, the maximum 665 mm. Thus, a working height of 820 - 865 mm is possible. Further details on the production and characteristics of our tables can be found in our catalogue. The illustrations do not correspond to the original size and are for llustration purposes only. 3D welding table - 3D clamping devices - 3D precision welding table

Condition: used, table length 1000 mm table width 1000 mm table load / t weight 1100 kg table height 100 mm Ijdpfxegrndio Addotb

Condition: new, Year of construction: 2025, diameter 28 mm length 75 mm clamping range 70-75 mm The price is exclusive of statutory VAT. Also available in D28 x 50 mm (clamping range 45–50 mm). Clamping range: 70–75 mm Type: Ball Lock Pin 75 mm Diameter: 28 ± 0.02 mm Material: 45# steel Hardness: HRC28–32 Surface roughness: Ra 0.8 µm GERD WOLFF's ball lock pins are specialized fastening elements designed for integration into various welding table systems and setups. Their primary function is the efficient and precise positioning and securing of workpieces. These pins are compatible with welding tables from all manufacturers featuring 28 mm bore holes. The unique ball-lock design enables flexible alignment of workpieces at different angles and positions. Thanks to high-quality craftsmanship and robust construction, GERD WOLFF's ball lock pins provide reliable holding force throughout the entire welding process. These pins ensure easy handling, quick clamping, and release of workpieces — no additional tools required. GERD WOLFF stands for quality and precision in welding technology. These ball lock pins are engineered to meet the demanding requirements of professional welding applications. Iodsuia Ngjpfx Addstb Quick release locking pins, quick lock pins, quick releases, quick installation pin, metal horizontal quick release, working pin, quick release locking pin, quick latch pin, locking quick release pins.

Condition: used, table length 1000 mm Ijden Nc Nbspfx Addstb table width 475 mm table height 145 mm

Condition: used, table length 1000 mm Iodpfsrrzkhex Addjtb table width 475 mm table height 145 mm

Condition: excellent (used), Year of construction: 2010, Excellent condition can be demonstrated if required we also have a video of it running we have also got a tailstock if required Itsdpfx Adoq Rciledeb

Condition: excellent (used), HAAS TR310 TRUNNION TABLE EXELENT CONDITION TESTED CAN BE SHOWN WORKING Iodjnp Iyhspfx Addjtb

Year of construction: 1991, condition: good (used), Underfloor circular saw, crosscut saw, pull saw, chop saw, sliding table saw, table saw, circular saw, panel saw -Manufacturer: Altendorf, sliding table saw type TKR 45 -Main motor: Bauknecht 5.5 kW with brake -Scorer motor: Emod 0.75 kW -Speed: 3000/4000/5000 rpm Iodpfx Adjmydmbjdotb -Saw blade: Ø 300 mm / max. Ø 350 mm -Max. Cutting height: 90° 95 mm / 45° 70 mm -Miter cut: up to 45° -Cutting width: 2250 mm -Table length: 1400 mm -Dimension total 3480/1530/H1370mm -Weight: 1104 kg

Condition: new, functionality: fully functional, UNUSED / new / as new Vibrating Table Power: 400 VOLT 2x asynchronous three-phase eccentric motors With manual / documentation! Itjdpfxsvrl Ufj Addob The device can be viewed at my warehouse by appointment. Shipping and loading are of course possible!

Condition: excellent (used), Zwick / Roell Type: Z020 Allround-Line BT1-FR020TN.A50 Zwick / Roell Materials Testing Machine 20 kN Tensile & Compression Testing testXpert III Itsdpfjx Up Igox Addeb For sale is a high-quality Zwick / Roell materials testing machine for professional tensile and compression testing of materials and components. The machine is suitable for metals, plastics, rubber, and many other materials and is typically used in laboratories, quality assurance, research, and education. Control is via PC using Zwick/Roell testXpert III software (data carrier & documentation included). Technical Data: Rated test force: 20 kN Test direction: tensile & compression Power supply: 230 V / 50–60 Hz / single-phase Power consumption: approx. 2.1 kVA Weight: approx. 150–180 kg Dimensions: approx. 856 × 650 × 1,545–2,114 mm Technical data (according to documentation & nameplate) Mechanics / Testing Nominal force: 20 kN Testing direction: tensile & compression Max. test frequency: 0.5 Hz Crosshead: servo-electric Positioning accuracy: < 1 µm Speed range: 0.0005 – 1,000 mm/min Dimensions & Weight: Total height: approx. 1,545 – 2,114 mm (depending on crosshead position) Total width: approx. 856 mm Total depth: approx. 650 mm Working area width: 440 mm Weight: approx. 150 kg (base unit) approx. 180 kg with typical configuration Electrical Data Power supply: 230 V AC Phases: single-phase (1PH, N, PE) Mains frequency: 50 / 60 Hz Current consumption: approx. 8–10 A Power consumption: approx. 2.1 kVA Plug: Schuko (CEE 7) Measuring & Control Electronics: Internal data acquisition: 500 Hz Data transmission to PC: adjustable 10–100 Hz Interface: RS232 (COM) Electronics housing protection class: IP32 Important note: 'The table shown in the photos is not included in the sale.' Condition: used Scope of delivery: (see picture) - Zwick / Roell materials testing machine (20 kN) - Electronics unit - PC workstation (monitor, PC – please see photos for condition) - 2 measurement modules (Delock units) - Zwick/Roell testXpert III software (data carrier) - Original operating and technical documentation - Various connection and interface cables (Specifications are subject to change and errors excepted!) If you have any questions, we will be pleased to assist you by phone.

Condition: used, Year of construction: 1988, control Heidenhain 355 tool adaptor SK50 weight of the machine ca. 8 t Iedpfxef Tdvbo Addotb +++++ Please note: The machine is dismantled and ready for loading. It is not possible to show it under power or make a video. Our offer includes already the best pictures. So we don’t have and won’t send additional pictures. +++++

Condition: used, Year of construction: 1990, Expert Eda450 Size of table plate 450 mm weight of the machine ca. 380 kg Itjdpfxsf Nlrqo Addob +++++ Please note: The machine is dismantled and ready for loading. It is not possible to show it under power or make a video. Our offer includes already the best pictures. So we don’t have and won’t send additional pictures. +++++

Condition: used, Year of construction: 1970, table length 2200 mm table width 115 mm table load 600 t weight 3 t Ijdpfeudc Twex Addotb 2

Condition: used, Dreh- und kippbar für Schweißpistole oder für Plasma condition nicht geprüft +++++ Please note: The machine is dismantled and ready for loading. It is not possible to show it under power or make a video. Our offer includes already the best pictures. So we don’t have and won’t send additional pictures. Isdjidv Erjpfx Addstb +++++

Condition: ready for operation (used), For sale is a Nikken CNC 400 rotary table in very good condition! It is configured for a Mazak M32 control but can be adapted as needed. Table diameter: 400 mm. Dimensions (L/W/H): 740/240/420 mm. If you have any further questions, feel free to contact me. Ijdpfx Adoya Dtmedjtb