Threading Technology – Clamping Technology 520

158 Machine Taps UNC UNF UNEF UN-8 M MF NPSF Rp (BSPP) G NPT NPTF Rc (BSPT) STI SELF-LOCK Accessories NPSM/NPSC Tech. Info v c Product Finder 1.16 Recommended tap drill sizes for tapping internal threads LK-UNC Unified SELF-LOCK coarse thread EMUGE standard Nominal Size LK-Core hole dia. D 1 B Drill dia. (Line 1) P [T.P.I.] D 1 min. D 1 max. D Line 1 Line 2 LK-No. 6 32 0.1119 0.1219 0.1217 0.1142 LK-No. 8 32 0.1378 0.1468 0.1476 0.1417 LK-No. 10 24 0.1544 0.1654 0.1675 0.1575 LK-No. 12 24 0.1804 0.1904 0.1935 0.1850 LK- 1 / 4 20 0.2069 0.2179 0.2226 0.2087 LK- 5 / 16 18 0.2644 0.2774 0.2818 0.2677 LK- 3 / 8 16 0.3204 0.3344 0.3400 0.3268 LK- 7 / 16 14 0.3748 0.3908 0.3972 0.3819 LK- 1 / 2 13 0.4323 0.4493 0.4564 0.4375 LK- 9 / 16 12 0.4887 0.5067 0.5148 0.5000 LK- 5 / 8 11 0.5443 0.5633 0.5728 0.5512 LK- 3 / 4 10 0.6609 0.6819 0.6922 0.6693 LK-M Metric SELF-LOCK coarse thread EMUGE standard Nominal Size LK-Core hole dia. D 1 B Drill dia. (Line 1) P [mm] D 1 min. [mm] D 1 max. D Line 1 [mm] Line 2 [mm] [mm] [inch] LK-M 3 0.5 2.673 2.745 — 2.7 0.1063 LK-M 4 0.7 3.549 3.639 — 3.55 0.1398 LK-M 5 0.8 4.324 4.524 4.574 4.4 0.1732 LK-M 6 1 5.152 5.388 5.465 5.2 0.2047 LK-M 8 1.25 6.931 7.196 7.322 7 0.2756 LK-M 10 1.5 8.700 9.000 9.170 8.8 0.3465 LK-M 12 1.75 10.477 10.812 11.024 10.7 0.4213 LK-M 14 2 12.237 12.612 12.863 12.5 0.4921 LK-M 16 2 14.237 14.612 14.863 14.5 0.5709 LK-M 18 2.5 15.787 16.237 16.569 16 0.6299 LK-M 20 2.5 17.787 18.237 18.569 18 0.7087 LK-M 24 3 21.320 21.820 22.259 21.5 0.8465 Self-Locking Threads Sawtooth Profile P ≥ 36 T.P.I. (P ≤ 0.7 mm) P D 1 min. D 1 B D 1 max. With the Sawtooth profile the mentioned drill sizes have to be considered. If the hole diameter becomes too large, safe functioning is jeopardized. Self-locking taps are produced with an accurate profile. The Metric LK-female thread mates with a Metric ISO bolt of grade “6g“. Thread sizes of male fasteners are according to DIN 13, part 19.20. LK Thread Profile P < 36 T.P.I. (P > 0.7 mm) P D 1 min. D 1 B D 1 max. For the specification of the maximum core hole minor diameter, as a general rule, use Line 1. For special applications, machining heavy materials for example, depth of thread is 2 x diameter, or if higher tool life is required, it is possible to use Line 2. The maximum LK-minor core hole diameter listed in Line 2 cannot be exceeded as the performance of the EMUGE SELF-LOCK system would be negatively affected. Minimum LK-minor diameters should not go below those listed. It is possible to use Line 2 when machining heavy materials.