Found this info. else where but thought some folks here might be interest in knowing this. It works! I ordered the tap and it is the right one.

You can get the tap here..

http://www1.mscdirect.com/CGI/NNSRIT?PARTPG=NNSRAR2&PMPXNO=1735758

For drill bit information use this...

"Proper size is .282-.286 diameter. Best fit is 9/32 at .2812 or "K" at .2811 or 7.2mm at .2835.
I=.2720 not a problem in a soft metal."


Hope this helps...

PS: google MSC Industrial Supply Co for Promotional Code to cut the price down

Thanks for the heads-up this could solve a long standing problem!

What size is the tap? The link doesn't work without a customer login and they don't accept customers outside North America/Mexico.

John

I redone the link in the last post. give it another try.
here is a copy and past from the tap

Description: Hand - Taps Thread Type: NS Thread Size: 5/16-36 Chamfer Style: Plug Ground Thread Limit: H3 Material: HSS Finish/Coating: Bright
Thread Type: NS
Thread Size: 5/16-36
Chamfer Style: Plug
Ground Thread Limit: H3
Material: HSS
Finish/Coating: Bright
Overall Length (Inch): 2-23/32

Excellent, that works. Many thanks.

where did you find a promo code ?
i googled and looked but ??

thanks

http://www.retailmenot.com/coupons/industrialsupply

"NEW25" you get a 25% discount on your first order


another option google 5 16-36 tap you may find you can order it cheaper elsewhere