Page 731 - Yamawa_European_Catalogue_YEU21

25. Drill size and recommended hole size for forming taps

Intro

Unified Coarse Threads (UNC) Unit: mm Unified Fine Threads (UNF) Unit: mm
SP
Recommended Recommended
Minor Diameter Minor Diameter
Size Class Drill Hole Size Size Class Drill Hole Size
Size Size
Max. Min. Max. Min. Max. Min. Max. Min.
No. 1 - 64 UNC 2BX G4 1.582 1.425 1.71 1.75 1.67 No. 0 - 80 UNF 2BX G4 1.305 1.182 1.41 1.44 1.38
No. 2 - 56 UNC 2BX G4 1.871 1.695 2.01 2.05 1.96 No. 1 - 72 UNF 2BX G4 1.612 1.474 1.73 1.76 1.69 SL
No. 3 - 48 UNC 2BX G4 2.146 1.941 2.30 2.35 2.25 No. 2 - 64 UNF 2BX G4 1.912 1.756 2.03 2.06 1.99
No. 4 - 40 UNC 2BX G5 2.385 2.157 2.60 2.65 2.54 No. 3 - 56 UNF 2BX G4 2.197 2.025 2.33 2.37 2.29
No. 5 - 40 UNC 2BX G5 2.697 2.487 2.92 2.97 2.87 No. 4 - 48 UNF 2BX G5 2.458 2.271 2.64 2.68 2.59
No. 6 - 32 UNC 2BX G5 2.895 2.642 3.17 3.23 3.11 No. 5 - 44 UNF 2BX G5 2.740 2.551 2.95 2.99 2.90
PO
No. 8 - 32 UNC 2BX G6 3.530 3.302 3.84 3.89 3.78 No. 6 - 40 UNF 2BX G5 3.022 2.820 3.24 3.29 3.19
No. 10 - 24 UNC 2BX G6 3.962 3.683 4.37 4.44 4.30 No. 8 - 36 UNF 2BX G5 3.606 3.404 3.86 3.91 3.81
No. 12 - 24 UNC 2BX G6 4.597 4.344 5.02 5.08 4.96 No. 10 - 32 UNF 2BX G6 4.165 3.963 4.49 4.54 4.44
1/4 - 20 UNC 2BX G7 5.257 4.979 5.80 5.87 5.73 No. 12 - 28 UNF 2BX G6 4.724 4.496 5.09 5.14 5.03
ST
5/16 - 18 UNC 2BX G7 6.731 6.401 7.31 7.39 7.22 1/4 - 28 UNF 2BX G7 5.588 5.360 5.96 6.01 5.90
3/8 - 16 UNC 2BX G7 8.153 7.798 8.80 8.89 8.71 5/16 - 24 UNF 2BX G7 7.035 6.782 7.48 7.54 7.41
7/16 - 14 UNC 2BX G8 9.550 9.144 10.30 10.40 10.20 3/8 - 24 UNF 2BX G7 8.636 8.382 9.05 9.11 8.99
1/2 - 13 UNC 2BX G8 11.023 10.592 11.82 11.93 11.70 7/16 - 20 UNF 2BX G8 10.033 9.729 10.55 10.63 10.47
1/2 - 20 UNF 2BX G8 11.607 11.329 12.14 12.21 12.06 ROLL

Cylindrical Pipe Threads - G(BSP) Unit: mm
CARBIDE
Recommended
Minor Diameter Drill
Size Class Hole Size
Size
Max. Min. Max. Min.
G 1/8 - 28 - 8.848 8.566 9.29 9.36 9.22
LONG
G 1/4 - 19 - 11.890 11.445 12.53 12.64 12.42
G 3/8 - 19 - 15.395 14.950 16.03 16.14 15.92
G 1/2 - 14 - 19.172 18.631 20.12 20.25 19.99
HAND
TAPS
Helical Coil Wire Thread Inserts Metric Coarse (EG STI M) Unit: mm Helical Coil Wire Thread Inserts Metric Fine (EG STI MF) Unit: mm

Recommended Recommended
Minor Diameter Drill Minor Diameter Drill
Size Class Hole Size Size Class Hole Size EG (STI)
Size Size
Max. Min. Max. Min. Max. Min. Max. Min.
EG(STI) M 3 × 0.5 - 3.220 3.108 3.43 3.45 3.40 EG(STI) MF 10 × 1.25 10.483 10.271 11.04 11.10 10.99
EG(STI) M 4 × 0.7 - 4.292 4.152 4.59 4.63 4.56 EG(STI) MF 12 × 1.5 12.560 12.324 13.25 13.31 13.18
SPECIAL
EG(STI) M 5 × 0.8 - 5.334 5.174 5.67 5.71 5.64 EG(STI) MF 12 × 1.25 12.483 12.271 13.04 13.09 12.98 THREADS,
EG(STI) M 6 × 1 - 6.407 6.217 6.84 6.89 6.80 GAUGES
EG(STI) M 8 × 1.25 - 8.483 8.271 9.05 9.10 8.99
EG(STI) M 10 × 1.5 - 10.560 10.324 11.25 11.31 11.19
EG(STI) M 12 × 1.75 - 12.644 12.379 13.45 13.52 13.39 THREAD
MILLS

DIES

CENTER
DRILLS

Technical
info

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