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Inch Vs Metric Feed

Inch Vs Metric Feed

Inch Vs Metric Feed

(OP)
I am spec-ing out a radial drill for our Chinese operation. All our specifications are in inches and the machines available in that plant are metric feed, so I installed a digital read out that helped them with the drills and feeds. But what about tapping a thread (say 11/2 threads per inch) how do I tackle this part? Any ideas?

-Thanks

mechvhs

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2thumbsup Mech Rulz 2thumbsup

RE: Inch Vs Metric Feed

Tapping on a radial drill is done without feed. You engage the tap into the previously drilled hole and let the tap feed itself and then reverse the spindle and let the tap feed out. You sometimes have to apply some pressure to counter balance the wieght of the spindle. I believe your example of 11/2 is incorrect. More like 11 threads per inch or 2 mm pitch. These would easily be handled using the above process as long as the holes are through holes or holes with lots of clearance below the tap.

RE: Inch Vs Metric Feed

(OP)
That is 11 1/2 or .0869" pitch.

=========================================
2thumbsup Mech Rulz 2thumbsup

RE: Inch Vs Metric Feed

(OP)
Thanks for your reply BillPSU, but I am dealing with a radial drill w/ feed. For 11 1/2 TPI it feeds @ .087", I wonder if i can use the same tool and feed at 2.2085 mm on the metric feed machine ??

Regards,

mechvhs

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2thumbsup Mech Rulz 2thumbsup

RE: Inch Vs Metric Feed

Use a floating tap holder and get the feed as close as possible, just not higher.

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