BT-5 BT-20 BT-50 BT-55 BT-56 BT-58 BT-60 BT-80
BT-5 74% 56% 41% 40% 35% 33% 21%
BT-20 135% 75% 55% 55% 48% 45% 28%
BT-50 179% 133% 73% 73% 63% 60% 38%
BT-55 244% 181% 136% 99% 86% 81% 51%
BT-56 247% 183% 138% 101% 87% 82% 52%
BT-58 283% 209% 158% 116% 114% 94% 59%
BT-60 301% 223% 168% 123% 122% 106% 63%
BT-80 478% 353% 266% 195% 193% 169% 159%

 

Standard Estes & equivalent body tubes (Weights for 18" length)
Designation ID OD Weight Notes
BT5 0.515" (13.08mm) 0.541" (13.74mm) 0.205 oz (5.8g) 13mm Motor Tube
BT20 0.710" (18.03mm) 0.736" (18.69mm) 0.286 oz (8.1g) 18mm Motor Tube
BT50 0.950" (24.13mm) 0.976" (24.79mm) 0.384 oz (10.9g) 24mm Motor Tube
BT52 0.988" (25.10mm) 1.014" (25.76mm) 0.441 oz (12.5g) Slip fit over BT50
BT55 1.283" (32.59mm) 1.325" (33.66mm) 0.635 oz (18g)  
BT60 1.595" (40.51mm) 1.637" (41.58mm) 0.705 oz (20g)  
BT70 2.175" (55.25mm) 2.217" (56.31mm) 1.291 oz (36.6g)  
BT80 2.558" (64.97mm) 2.600" (66.04mm) 1.975 oz (56g)