Общий каталог Yamawa 2022 - 2023 - страница 1222

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Technical Description of productsInformation 21. Taps for Pipe Threads 3. Troubles on taper pipe thread tapping, and their solution Taper pipe thread tapping such as for PT thread and for NPT thread is quite different from parallel thread tapping such as for metric thread. There, the trouble particularly special in taper thread tapping tends to happen. Following is the explanation about tapping troubles on taper pipe thread tapping and their solution: ■ Materials and troubles material tool steel, alloy steel, thermosetting nickel base alloy, low carbon steel middle carbonsteel high carbon steel,heat treated steel ofstainless steelcast iron, tough aluminum alloy,cast ironzinc alloy, brassresin,thermoplastictitanium alloy, heattreated steel of lower trouble lower than 35HRC resin than 35HRC tap wear, cutting ▲ ● ▲ ● ー performance decreased welding on tap ● ● ▲ ● ● ー chipping on tap ▲ ▲ ● ● ー rough surface ▲ ▲ ▲ ▲ ● ▲ ▲ ー torn threads ● ● ▲ ● ▲ ー chip clogging ● ● ▲ ー ● Trouble occurs quite frequently　　▲ Trouble occurs rather frequently 　　ー Hard-to-machine material ■ Trouble shooting trouble Over-cutting of Shrinkage of Rough surface,check pointinternal threadsinternal threadsTorn threadsStop linetap wear, cuttingperformancewelding on tapchipping on tapchip cloggingdecreased Used machine Select machine suitablefor tapping size Use machinewith more power Use machinewith more power Use tap holder of floating type, Jigs, Holders Fix workpiecefirmly Prevent vibratingof axis of tap, Prevent centering- off with workpiece Adjust properly the stroke of tapping Cutting condition Reduce cuttingspeed, Adjust a Reduce cuttingspeed Reduce cutting speed feed Lubricant Change to insoluble oil from water soluble, Useother cutting oil which prevents cold weldingChange to insoluble oil from water soluble, Useother cutting oil when prevents cold weldingAdjust oil volume, supply oil properly Provide deeper Provide deeper On process Prevent slanting ofhole Use taper reamerfor boring holetapping hole, tapping hole,RemoveCheck the viscosity,unnecessary chipsUse taper reamer during tapping for boring hole Selection Use spiral flutedtap, Useinterrupted tapUse thread millcuttersUse carbide tap(depending onmaterials being cut)Use interruptedtapsUse spiral fluted tap, Use interruptedtap Tap Design Reconsider ofnumber of flutesof tapChange materialof tapProvide oxidesurface treatment,Provide TiN orTiCN on taps,Provide largercutting angleSelect longshank tap whenejecting chipsinterferes withtap holder in thecase of SPtapping ■ Examples of trouble shooting 1) Torn thread trouble was solved by changing cutting speed 2) Stop line trouble was solved by using Thread milling cutter Tapping condition Cutting condition size ： PT1/4-19 size ： PT1/4-19 tap ： Straight flute tap tap ： Straight flute tap material ： SS400machine ： Machining center millingcutter： 08153X19G holder ： fixed type material ： SS400 lubricant ： water soluble Tapping speed: 5m/min Tapping speed: 2.5m/min machine ： Machining center Straight flute tap Thread milling cutter Torn threads No torn threads holder ： fixed There is the stop line There is no stop line lubricant ： water soluble Technical-71