Page 721 - Yamawa_European_Catalogue_YEU21

24. Drill size and recommended hole size for cutting taps

Intro

Unified Threads (8UN) Unit: mm Unified Extra Fine Threads (UNEF) Unit: mm
SP
Minor Diameter Minor Diameter
Size Drill Recommended Size Drill Recommended
Size Hole Size Size Hole Size
Max. Min. Max. Min.
1“1/8 - 8 UN 25.781 25.146 25.50 25.62 No. 12 - 32 UNEF 4.826 4.623 4.70 4.78
1“1/4 - 8 UN 28.956 28.321 28.50 28.80 1/4 - 32 UNEF 5.689 5.487 5.60 5.64 SL
1“3/8 - 8 UN 32.131 31.496 31.80 31.97 5/16 - 32 UNEF 7.264 7.087 7.10 7.22
1“1/2 - 8 UN 35.306 34.671 35.00 35.15 3/8 - 32 UNEF 8.864 8.662 8.70 8.81
1“5/8 - 8 UN 38.481 37.846 38.10 38.32 7/16 - 28 UNEF 10.337 10.135 10.20 10.29
1“3/4 - 8 UN 41.656 41.021 41.30 41.50 1/2 - 28 UNEF 11.938 11.710 11.80 11.88
PO
2- 8 UN 48.006 47.371 47.80 47.85 9/16 - 24 UNEF 13.385 13.132 13.20 13.32
5/8 - 24 UNEF 14.986 14.732 14.80 14.92
3/4 - 20 UNEF 17.957 17.679 17.80 17.89
Unified Threads (12UN) Unit: mm 7/8 - 20 UNEF 21.132 20.854 21.00 21.06
ST
1- 20 UNEF 24.307 24.029 24.10 24.24
Minor Diameter Drill Recommended
Size 1“1/8 - 18 UNEF 27.381 27.051 27.20 27.3
Size Hole Size
Max. Min. 1“1/4 - 18 UNEF 30.556 30.226 30.30 30.47
1“5/8 - 12 UN 39.446 38.989 39.10 39.33 1“3/8 - 18 UNEF 33.731 33.401 33.50 33.65
1“3/4 - 12 UN 42.621 42.164 42.30 42.51 1“1/2 - 18 UNEF 36.906 36.576 36.70 36.82 ROLL
2 - 12 UN 48.971 48.514 48.60 48.86 1“5/8 - 18 UNEF 40.081 39.751 39.80 40.00

CARBIDE
Cylindrical Pipe Threads - G(BSP) Unit: mm Parallel Internal Pipe Threads - Rp(BSPP) - PS Unit: mm
Minor Diameter Drill Recommended Minor Diameter Drill Recommended
Size Size
Size Hole Size Size Hole Size LONG
Max. Min. Max. Min.
G 1/16 - 28 6.843 6.561 6.75 6.77 Rp 1/16 - 28 6.632 6.490 6.50 6.55
G 1/8 - 28 8.848 8.566 8.75 8.78 Rp 1/8 - 28 8.637 8.495 8.50 8.55
G 1/4 - 19 11.890 11.445 11.75 11.78 Rp 1/4 - 19 11.549 11.341 11.40 11.50
HAND
G 3/8 - 19 15.395 14.950 15.25 15.28 Rp 3/8 - 19 15.054 14.846 14.80 14.90
TAPS
G 1/2 - 14 19.172 18.631 19.00 19.04 Rp 1/2 - 14 18.773 18.489 18.50 18.55
G 5/8 - 14 21.128 20.587 21.00 21.00 Rp 5/8 - 14 20.729 20.445 20.50 20.55
G 3/4 - 14 24.658 24.117 24.50 24.52 Rp 3/4 - 14 24.259 23.975 24.00 24.10
G 7/8 - 14 28.418 27.877 28.25 28.28 Rp 7/8 - 14 28.019 27.735 27.75 27.80 EG (STI)
G 1 - 11 30.931 30.291 30.75 30.77 Rp 1 - 11 30.472 30.110 30.20 30.25
G 1 1/8 - 11 35.579 34.939 35.30 35.42 Rp 1 1/8 - 11 35.120 34.758 34.75 34.80
G 1 1/4 - 11 39.592 38.952 39.30 39.43 Rp 1 1/4 - 11 39.133 38.771 38.75 38.80
SPECIAL
G 1 1/2 - 11 45.485 44.845 45.25 45.33 Rp 1 1/2 - 11 45.026 44.664 44.60 44.70 THREADS,
G 1 3/4 - 11 51.428 50.788 51.25 51.27 Rp 1 3/4 - 11 50.969 50.607 50.60 50.70 GAUGES
G 2 - 11 57.296 56.656 57.00 57.14 Rp 2 - 11 56.837 56.475 56.50 56.60
G 2 1/2 - 11 72.866 72.226 72.50 72.70 Rp 2 1/4 - 11 62.933 62.571 62.50 62.60
G 3 - 11 85.566 84.926 85.25 85.40 Rp 2 1/2 - 11 72.442 72.010 72.00 72.10 THREAD
G 3 1/2 - 11 98.012 97.372 97.75 97.90 Rp 3 - 11 85.142 84.710 84.75 84.80 MILLS
G 4 - 11 110.712 110.072 110.50 110.60 Rp 3 1/2 - 11 97.588 97.156 97.20 97.30
Rp 4 - 11 110.288 109.856 109.90 110.00
DIES

CENTER
DRILLS

Technical
info

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