Общий каталог Yamawa 2021 - страница 701

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19. The mechanism for a tap to cut oversize on an internal thread Intro 1. Run out, misalignment and tap doesn’t cut perpendicular into holes Over-cutting at radial direction SP Tool run out during tapping Misalignment during tapping Tapping a non-parallel or non-perpendicular thread to the axis of the hole. Holder needs to be Axis of tapping process Verification of holder holder holder holder adjusted. Tapping with and bored hole should prepared hole run out can be observed SL and checked when idle be lined up correctly. The use of adjustable condition. running. holder with floating features will reduce this Lateral force problem. Solutions PO misalignment Run out ST Excessive cutting in radial direction causes oversized internal threads. Since tapping proceeds along bored hole, in the depth of hole, oversize cutting is minimized, that is, oversize cutting in the beginning of the hole and normal cutting in the depth of the hole. ROLL Excessive-cutting in the radial direction Normal internal threads CARBIDE Not Go gauge Over sized Normal Not Go internal threads internal gauge internal threads at the beginning Not Go gauge LONG of the bore threads HAND TAPS 2. Using a tap not suitable for the operation or a tap with dull Over-cutting caused by galling and excess cutting cutting edge may cause galling and result in over-cutting. EG (STI) Using an incorrect tap for a specific workpiece material Tapping process with dull edge can cause problems Wear Welding Chipping Select the correct Tap Flank SPECIAL • Straight fluted tap THREADS, • Spiral fluted tap GAUGES • Spiral pointed tap • Roll tap Parallel [Wear] wear [Welding] [Chipping] Selection of correct taps suitable for material being THREAD tapped is strongly recommended. Solution: Proper use of cutting oil, confirmation of a constant for tool life MILLS DIES Torn threads occur on the thread flanks. If this situation gets worse, there occur large thread Incomplete thread Over-cutting caused by collapses or incomplete threads finally bringing out galling and excess feeding oversized internal threads. Incomplete Depending on the condition of collapsed threads thread such trouble tends to occur discontinuously as CENTER NOT-GO gouge enters. Special attention needs to be taken so that random DRILLS inspection should not miss this kind of trouble. Incomplete thread Not Go gauge Technical info 702