GBP 57 ISO code / factory standard, indexable turning inserts Fastening and chip breaker m m Hole configuration Chip breaker Insert type Ød Ød S A Cylindrical hole none Form, Main clearance Tolerance* (factory standard) indexable insert angle B Cylindrical hole + Tolerance Tolerance Thickness none C Rhombus 80° 80° 3° Countersink A with radius in circle tolerance C (70 ≈ 90°) m ⌀d S F - double-sided D Rhombus 55° 55° 5° mm mm mm B G Cylindrical hole double-sided A ± 0.005 ± 0.025 ± 0.025 G Rhombus 45° 45° H Cylindrical hole single-sided C ± 0.013 ± 0.025 ± 0.025 C 7° + Countersink K Rhomboid 55° 55° E ± 0.025 ± 0.025 ± 0.025 J (70 ≈ 90°) double-sided F ± 0.005 ± 0.013 ± 0.025 D 15° M Cylindrical hole single-sided R Round G ± 0.025 ± 0.025 ± 0.13 N - none H ± 0.013 ± 0.013 ± 0.025 S Square 90° G 30° Cylindrical hole J ± 0.005 ± 0.05 up to ± 0.15 ± 0.025 + Q none Countersink T Triangle 60° (40 ≈ 60°) K ± 0.013 ± 0.05 up to ± 0.15 ± 0.025 N 0° R - single-sided L ± 0.025 ± 0.05 up to ± 0.15 ± 0.025 V Rhombus 35° 35° T single-sided M ± 0.08 up to ± 0.20 ± 0.05 up to ± 0.15 ± 0.13 Cylindrical hole 11° P + N ± 0.08 up to ± 0.20 ± 0.05 up to ± 0.15 ± 0.025 U double-sided W Trigon 80° 80° Countersink (40 ≈ 60°) further P* ± 0.04 ± 0.04 ± 0.04 W none X/Z Special shape O clearance angles U ± 0.13 up to ± 0.38 ± 0.08 up to ± 0.25 ± 0.13 X - - Special design C N M G 12 04 08 P F N Inner circle ⌀ for insert size Thickness Corner radius Adjustment angle Cutting edge Machining version direction mm mm Inner circle C D G K R S T V W (mm) 00 without sharp-edged R right-hand 3.970 03 03 06 02 4.100 S4 S5 01 0.1 kr F 4.920 06 5.000 05 03 02 0.2 L left-hand 5.560 05 09 6.000 06 S4 1.16 03 0.3 6.350 06 07 06 11 11 04 A 45° 7.000 07 04 0.4 honed N neutral 01 1.59 7.940 08 09 07 13 05 8.000 08 08 D 60° E 05 0.5 8.200 14 T1 1.98 9.525 09 11 16 09 16 16 06 06 0.6 10.000 10 02 2.38 E 75° 11.000 11 08 0.8 12.000 12 07 T2 2.78 chamfered 12.700 12 15 12 22 22 08 14.290 09 10 1.0 F 85° T 15.875 16 19 15 27 10 03 3.18 16.000 16 12 1.2 19.050 19 23 19 33 T3 3.97 MO Round 20.000 20 15 1.5 21.000 13 04 4.76 chamfered and 22.225 22 27 22 38 16 1.6 honed P 90° 25.000 25 25.400 25 31 25 44 05 5.56 S 20 2.0 26.194 17 31.750 32 38 31 55 Z special 06 6.35 24 2.4 32.000 32 720