• for General Bicycle Threads (BC)
  • for European Steel Conduit Threads (Pg)

Unit:mm Unit:mm

Minor diameter of internal threads(D1)Tap drill hole size
SizeMax.Min.(reference)
BC5/16 -26 7.167.067.14
BC3/8 -26 8.758.658.73
BC7/16 -26 10.3310.2310.31
BC1/2 -20 11.6611.5511.63
BC9/16 -20 13.2513.1413.22
BC5/8 -20 14.8414.7314.81
BC11/16 -24 16.5916.4816.56
BC3/4 -30 18.4018.2918.37
BC31/32 -30 23.9623.8523.93
BC1 -24 24.5824.4624.55
BC1.29 -24 31.9631.8331.93
BC1.37 -24 33.9933.8633.96
BC1 7/16 -24 35.7035.5735.67
BC1.45 -24 36.0235.8935.99
BC1 9/16 -24 38.8838.7538.85
Minor diameter of internal threads(D1)Tap drill hole size
SizeMax.Min.(reference)
Pg7 -20 11.4311.2811.39
Pg9 -18 14.0113.8613.97
Pg11 -18 17.4117.2617.37
Pg13.5 -18 19.2119.0619.17
Pg16 -18 21.3121.1621.27
Pg21 -16 27.0326.7826.97
Pg29 -16 35.7335.4835.67
Pg36 -16 45.7345.4845.67
  • For miniature threads
  • For trapezoidal threads

Unit:mm Unit:mm

SiMinor diameter of internal threads(D1)Tap drill hole size
zeMax.Min.(reference)
S0.4×0.10.3300.3040.32
S0.5×0.1250.4150.3800.41
S0.6×0.150.5020.4560.49
S0.7×0.1750.5850.5320.57
S0.8×0.20.6650.6080.65
S0.9×0.2250.7450.6840.73
Minor diameter of internal threads(D1)Tap drill hole size
SizeMax.Min.(reference)
Tr 10×28.2368.0008.2
Tr 12×39.3159.0009.2
Tr 12×210.23610.00010.2
Tr 14×311.31511.00011.2
Tr 16×412.37512.00012.3
Tr 16×313.31513.00013.2
Tr 18×414.37514.00014.3
Tr 20×416.37516.00016.3
Tr 22×517.45017.00017.3
Tr 24×519.45019.00019.3
Tr 25×520.45020.00020.3
Tr 26×521.45021.00021.3
Tr 28×523.45023.00023.3
Tr 30×624.50024.00024.4
Unit:mm
SizeMinor diameter of internal threads(D1)Tap drill hole size
Max. Min.(reference)
20.32W3619.550 19.47419.53

Technical Inf