hole size for taps

[herb white]

I need a chart that tells what size hole to drill when cutting threads in metal. Where would I find that ? thanks a lot herb

[trader4]

I'd bet that if you used google, you'd find it in about 5 secs. Google is your friend.

[DerbyDad03]

Do they have Google where you live?

[Terry Coombs]

Google is *NOT* your friend !! It is one of the biggest data-mining operations on the web , and they have been known to turn over your info to the feds . A much better option is

, which uses Google's search function but they do not record or store any of your information . There are other search engines that are similar , but I like startpage .

[jamesgang]

Most of my taps have the drill size on the side of the tap.

[RobertMacy]

From sci.eletronics.repair group, useful to know tidbit:

Mark Storkamp Oct 9, 8:47 am

- Show quoted text -

For any size thread you plan to tap, to find the hole size just subtract the pitch of the thread from the diameter of the thread. For an M3x.5 that would be 2.5, for a 1/4-20 it would be .25-1/20, .25-.05, or .2 (#7 drill is .201), etc.

also I have four pages of tables metric-fine

metric-coarse

National-coarse

National-fine

don't know if they still exist, though

[DerbyDad03]

True, but sometimes it's nice to refer to a chart that gives tap size, drill size, thread size, etc. Something like this...

[Harry K]

Being too lazy to go in the house to look it up on the 'net I take a short cut.

I open my drill index and look at the chart imprinted on the dill holder.

Harry K

[trader4]

So you say. I'll bet Google will find him his tap table. Google works for me and hundreds of millions of other people. Google's Android works mighty fine on my Smartphone. I've had no problems with google invading my privacy. What do you have to hide? This is like the nuts that have it in for MSFT, Apple, and insist we should all be using Linux. I say, use what works for you.

[Jon Danniken]

I like this one:

Jon

[DerbyDad03]

That's a nice link. It includes the chart I linked to as well as a few other useful charts.

Here's another chart that I have hanging next to my drill press. It comes in handy every now and then...

[albosch]

Just for the sake of saying it, There is a good APP for I-phone called Drill Chart. Covers Metric and American. I use it almost every day at work.

[clare]

Lots of them online - or do the simple calculation - nominal diameter less .75Xpitch is a good rule of thumb. so a 1/4X20 gets ..2125 - the tables say.2188 for 50% thread

1/2X20 would be .4625 - tables say .4688 for 50% thread (iron and steel). For plastic or brass the book says .4531 (75% thread).

BUT - you obviously have a computer with internst connection so just google "tap drill size" and print off the chart.

[clare]

Just don't use Goiogle Chrome as your browser and you are relatively safe.

[clare]

But I always misplace my jeweller's loupe, so half the time I can't read them - - - -

[clare]

Works if you have a half decent drill index. The cheapassed drill sets half the guys on here have are doing good to have the DRILL size stamped in a readable form.

[willshak]

There is nothing on the web that is your 'friend'. The whole internet is based on ad revenue. You might say that these newsgroups are friendly, but then you have the HomeownersHub, et al. which steals the posts here and puts them on their website which is funded by ads.

[krw]

Why do you believe that Ads == bad?

[DerbyDad03]

Why is that an issue? I frequent many forums where I both get help and provide help on subjects ranging from software applications to car repair. If you asked me to tell you about any of the ads on those websites, I couldn't. I just ignore them.

If I ask a question about fixing a 2002 Mitsubishi Galant and someone helps me out, that's friendly. If someone asks a question about VBA programming and I provide an answer, that's friendly. If either one of us follows up with a sincere "thank you" for the help, that's even friendlier.

Who cares if the website is funded by ad revenue? As long as i can give or get the help I went to the website for, the ads don't matter.

Granted, there are websites where the ads so obnoxious or set up so that they make it hard to use the website. When I encounter one of those websites, I click the little X in the upper right corner and never go back.

[micky]

Samsung let me back up my phone contacts and data straight to my computer, but for my android phone, Google wanted my phone number before it would do anything.

Every time I log in to google it wants my phone number.