tip31.pdf datasheet:

SEMICONDUCTORTIP31TECHNICAL DATA TRANSISTOR (NPN) TIP31/31A/31B/31CAOCFE FEATURESBDIM MILLIMETERSMedium Power Linear Switching Applications A 10.15 0.15 B 15.30 MAXC 1.3+0.1/-0.15PD 0.8 0.1E 3.8 0.2F 2.7 0.2JH 0.4 0.15DJ 13.6 0.2N 2.54 0.2HN NMAXIMUM RATINGS (Ta=25 unless otherwise noted) O 4.5 0.21 2 3P 2.7 0.2Symbol Parameter TIP31 TIP31A T TIP31C UIP31B nitVCBO Collector-Base Voltage 40 60 80 100 V 1 BASEVCEO Collector-Emitter Voltage 40 60 80 100 V 2 COLLECTOR3 EMITTERVEBO Emitter-Base Voltage 5 V IC Collector Current 3 A PC Collector Power Dissipation 2 W RJA Thermal Resistance from Junction to Ambient 62.5 TO-220ABTj Junction Temperature 150 Tstg Storage Temperature -55~+150 ELECTRICAL CHARACTERISTICS (Ta=25 unless otherwise specified) Paramet