Tap and die ??

[2001300exguy]

i need to know what size hole to drill for a 3/8 bolt to be able to tap it out. is there sort of chart you know i could look at also.thanks

[ImWhite]

i just bought one awhile ago,never used it tho,im pretty sure u just drill a small hole then tap the thing in w/ a hammer and re-drill out,kinda easy i think

[2001300exguy]

i know how to use it but i ned to know what size hole to drill for a 3/8 bolt so it can be tapped. i know it needs to be smaller but i need to know what size, its drilled out to 5/16 right now and theres still to much material in ther to tap it out.

[ImWhite]

just go 1 size bigger at a time and try it then?i dont think there is a chart,but maybe im wrong

[400exrules]

i was gonna say a 5/16, but you said its too small, so idk what to tell you, are you sure its 5/16? cuz thats the size you need

[circusfreak6]

pmed you

[2001300exguy]

pmed back

[Chino]

Originally posted by ImWhite
i just bought one awhile ago,never used it tho,im pretty sure u just drill a small hole then tap the thing in w/ a hammer and re-drill out,kinda easy i think

you NEVER EVER EVER use a hammer to start a tap, this kid has no clue what he is talking about, you need to measure the threads on the bolt with the tool that comes with your tap/die set. Then refer to your chart to see which combination to use. It's not a very hard thing to do, but you can do as much damage using these as you can good if you have no clue what your doing. You never want to thread something all the way at one time either, use some good lubrication and thread it a few threads then back it out then thread it back in and make two or three more sets of threads then back it out and so forth, it's a time consuming process when done correctly but when done correctly it will last, instead of the threads giving away doing it im-properly. Also make sure your tap/die are on straight when you are threading something, don't just thread it on crooked so it will work.

[2001300exguy]

i know the pitch and everything but i dont have a chart to look at if anyone could scan one and email to hxc400exr@sbcglobal.net i would greatly appreciate it

[circusfreak6]

use a 3/8 16 tap, predrill with a letter P drill, wich converts to .323. you can use a drill thats close to that size, i wouldnt go much over +/- .010. hope this helps. for threading, do what the guy above posted. thats the exact way. I cant scan the chart cause its in a machinist ready reference book.

[Lucky33]

For a 3/8 - 16 tap you need a 5/16 hole.

[circusfreak6]

that would work also. the threads would be a little sloppy tho.

[Rip_Tear]

Originally posted by Lucky33
For a 3/8 - 16 tap you need a 5/16 hole.

Exactly. What material are you tapping? how many flutes is the tap? are you using cutting oil? How many TPI is the tap? there are 2 common 3/8 TPI.

[circusfreak6]

i pm'ed him and told him to count the tpi, i posted exactly what he needs

[circusfreak6]

this chart is a little basic. its not exact figures but itll work. my book said to use a P drill and this chart says to use 5/16. it doesnt really matter the sizes are only .010 apart.

http://www.kramerusa.com/DrillTapChart.htm

[2001300exguy]

thank alot guys