B-25 Dimensions & Specifications Dimensions (millimeters in shaded area) A B C B-25 7.00 2.60 - F G H L O P R AA AC 1/4-20 7.00 B-25A 8.00 3.13 B-25 177.8 66.0 D E 2.25 0.50 0.39 1.31 - 1.1255 - 0.88 - 9.23 1/4-20 7.50 AE1 AE2 2.25 0.35 0.76 1.46 13.94 1.1255 5.97 0.88 2.69 1/4-20 178.8 57.2 12.7 9.9 33.2 22.2 - B-25A 203.2 79.4 239.4 1/4-20 190.5 57.2 8.9 19.4 37.0 354.2 28.58 151.6 22.2 - - 28.58 - Z Keyway Set Screws 7.50 1/4 X 1/8 (2) 5/16-18 0.83 13.18 7.50 0.83 1/4 X 1/8 (2) 5/16-18 190.5 6.4 X 3.2 (2) 5/16-18 21.1 334.8 190.5 6.4 X 3.2 (2) 5/16-18 21.1 68.4 - Specifications (metric in shaded area) Model Rated Torque (lb-ft) (Nm) Heat Dissipation at 1800 rpm of Outer Member Watts hp Non Excited Drag Torque (lb-ft) (Nm) Inertia (WR2) of Outer Rotating Member (lb-ft2) (kg-m2) WT (lb) (kg) Coil Data (90 VDC) Time Constants (Seconds) Rated Current Ω@ 20˚C Current Torque B-25 25 231 0.31 0.40 0.08 20.0 0.30 194 0.18 0.26 B-25A 25 646 0.87 0.40 0.08 28.0 0.30 194 0.18 0.26 B-25 33.9 231 0.31 0.50 0.00337 9.0 0.30 194 0.18 0.26 B-25A 33.9 646 0.87 0.50 0.00337 13.0 0.30 194 0.18 0.26 Time constants are the time in seconds for current or torque to reach 63% of the final value after step function voltage is applied. "Rated current" is the current which will occur from a 90 VDC input to the clutch when the unit is operated at its rated temperature (maximum heat dissipation). Non excited drag torque and torque time constant measured at 1800 rpm. Axis of shafts must lie within 30˚ of horizontal. Brake mounting should be 'floating' type, to prevent overloading bearings. Fan power requirements are 115 VAC, 60 Hz, 1.37 amp. Non-excited drag torque values represent a typical unit after a few minutes of use. Drag torque in a new, unused unit may initially be higher. Magnetic Particle Clutches & Brakes 125 Magnetic Particle Clutches & Brakes Model