Information for the amateur

[Tozguy]

Never used the nut gauge trick. For this trick to work with many of the finer threads it might be important to have a complete set of drills in 64ths to try. If you have a complete set of letter and number drills also then pass GO and collect 200$.

Even when using a chart, if the tap drill size specified is one you don't have, then I would go to the next larger drill on hand even if it does not fit through the nut. In these cases it is good to know how much thread engagement you are sacrificing.

Thread fit is basic knowledge for even a hobbyist and understanding thread charts is a prerequisite to choosing your first tap and die set (in my arrogant but humble opinion).

 

[chips&more]

Maybe not found in every HM shop. But there are “formtaps”. They do not cut. They form the tread. Typical 65% to 75% thread. And they make very nice threads!!!

 

[magicniner]

Maybe not found in every HM shop. But there are “formtaps”. They do not cut. They form the tread. Typical 65% to 75% thread. And they make very nice threads!!!

Thread forming taps are very good for producing strong threads in a lot of plastics, I use them for small threads in Nylon parts.

 

[jpfabricator]

I've advanced to the point of having small plastic containers with tap, tap drill and clearance drills all together for each size, 4-40 through 1/2-13. But it took years to set it up.

Im currently doing the same, but in plastic padded envelopes that fit in a small box. I use a permanent market and write all the info on the front.

Jake Parker

 

[benmychree]

That might have worked at one time but since I’m 72 it doesn’t work now. At my age my mind is too full of bs like passwords and user names.


Sent from my iPad using Tapatalk

You too? I have a rolodex, I call it my memory.

 

[MrWhoopee]

Quote by Albert Einstein: “Never memorize something that you can look up.”

I learned the "subtract the pitch from the major diameter" trick as a young apprentice. Can't remember the last time I used a chart. There are a lot of other things I can't remember.

 

[P. Waller]

Quote by Albert Einstein: “Never memorize something that you can look up.”

I learned the "subtract the pitch from the major diameter" trick as a young apprentice. Can't remember the last time I used a chart. There are a lot of other things I can't remember.

That is the beauty of this relationship, it gives a reasonable approximation for a 60-70 percent thread in all 60 Deg. single start V-Threads in a simple easy to remember form, no charts are required
Do not confuse thread "pitch" with thread lead however.

 

[RJSakowski]

That is the beauty of this relationship, it gives a reasonable approximation for a 60-70 percent thread in all 60 Deg. single start V-Threads in a simple easy to remember form, no charts are required
Do not confuse thread "pitch" with thread lead however.

Actually, the major diameter - pitch for tap drill size will always yield a 77% thread.

It's dead simple to remember; a subtraction for metric threads, a division to convert tpi to pitch and a subtraction for SAE threads. Write it on the cover of the drill index and you will always know the correct tap drill. No more excuses.