On Sun, 03 Nov 2013 15:40:15 -0500, you wrote: >Spiral point taps are made for through hole tapping.. they tend to push >the chips ahead of the tap. Not good for a blind hole. > >http://www.shars.com/product_categories/view/2160902/HSS_Spiral_Point_TapsPlug_Style > >Spiral flute taps work well for blind holes. >http://www.grainger.com/Grainger/WIDIA-GTD-Spiral-Flute-Tap-1TRK6?Pid=search >http://www.shars.com/product_categories/view/807222403/HSS_HiSpiral_Flute_Tap_USA > >Not cheap though...
Depends what you call "cheap". You get what you pay for. I use Dormer brand machine taps (hand or tapping head) M6x1 spiral point tap is £12 ($19) - M6x1 spiral flute is £15 ($24). Plain black steam tempered. Coated are more expensive. Depending on material, lube etc they are good for 3500 cycles or so at 10mm thread depth with machining rates I cant possibly match. No peck or any of that - just driven in and out and work out very cheap per hole :) I did 200 holes a few weeks ago in a 10mm steel pre drilled jig plate I couldn't get on the mill using a DeWalt 18V hand drill with a well used spiral point tap and some Rocol tapping fluid. I don't buy "cheap" taps - learnt my lesson when I snapped a 2.5mm tap in a nearly finished turbine housing. A 50 mile round trip to get my borrowed spark eroder back and hours to get the broken tap out taught me that one. Steve Blackmore -- ------------------------------------------------------------------------------ Android is increasing in popularity, but the open development platform that developers love is also attractive to malware creators. Download this white paper to learn more about secure code signing practices that can help keep Android apps secure. http://pubads.g.doubleclick.net/gampad/clk?id=65839951&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
