Drill and Tap Chart

BooBoo

BooBoo

AzB Silver Member
Silver Member
This is all new to me so please excuse my ignorance. Let's say I want to insert a 3/8 x 10 pin, what would the drill size be for the hole. I have the taps, just need the proper drill sizes, or is there a formula on how to figure them out? Interested in the standard sizes. 5/16 x 14, 5/16 x 18, 3/8 x 10,
Thanks in advance.
 
i think he means drill size to tap size

like 5x16-14 and 18 drill bit is 1/4

3x8-10 and 11 drill bit is 5/16

some dont drill they bore.

youll also need a center drill set. i personally step drill EVERYTHING for accuracy

this means after i get my piece running perfectly true i will start with the smallest center drill and work my way up to the size i need

takes a bit more time but im in no hurry

in my set center drill 3 is .250 ( perfect for 5x16-14 and 18) and 4 is .308 (perfect for 3x8-10 and 11)

some makers will drill the wood joints smaller for a tighter fit. like .302 instead of .308

hope this helped
TN_Center_Drills.jpg
 
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dave sutton said:
i think he means drill size to tap size

like 5x16-14 and 18 drill bit is 1/4

3x8-10 and 11 drill bit is 5/16

some dont drill they bore.

youll also need a center drill set. i personally step drill EVERYTHING for accuracy

this means after i get my piece running perfectly true i will start with the smallest center drill and work my way up to the size i need

takes a bit more time but im in no hurry

in my set center drill 3 is .250 ( perfect for 5x16-14 and 18) and 4 is .308 (perfect for 3x8-10 and 11)

some makers will drill the wood joints smaller for a tighter fit. like .302 instead of .308

hope this helped
TN_Center_Drills.jpg
Click to expand...
my apologies to mr boo boo
i thought he was asking,
what size hole do i drill/bore for such and such pin?

good catch dave :thumbup:
i posted the wrong link
crap, now i cant find the right chart again
i need more coffee :thumbup:

 
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Thanks alot. I've worked with taps before, but never had to know the drill size. I'll probably have more questions for you, but one step at a time.
 
Hi Boo Boo,
It is thread specific, the drill or hole size for a given tap. Ie If it is a normal full form 60 deg thread angle tap, an aproximate guide , it to subtract the pitch from the diameter.
Eg 3/8 - 10 tpi would be .375 -.1(10 tpi pitch distance for 1 pitch)=.275
However, this is not true for thread forms like the radial style , or the Southwest style of thread form.
But for the
5/16-18 tpi bore is .257 or a F drill,

5/16-14 tpi C drill or 6.1 mm

3/8-10 tpi 7mm drill or a J

Here is a link to a site with lots of drill tap info, but the std charts do not cover most of what is used in cue joints.

http://www.engineersedge.com/tap_drill_chart.htm

http://www.engineersedge.com/drill_sizes.htm

http://www.engineersedge.com/manufacturing_design.shtml

Neil
 
BooBoo said:
Thanks alot. I've worked with taps before, but never had to know the drill size. I'll probably have more questions for you, but one step at a time.
Click to expand...


ok pm me if you need help. it comes right to me cell. i cant find my prather catalog . when i do i will scan the chart and post it. but you need one anyway so call them.

www.prathercues.com
 
conetip said:
Hi Boo Boo,
It is thread specific, the drill or hole size for a given tap. Ie If it is a normal full form 60 deg thread angle tap, an aproximate guide , it to subtract the pitch from the diameter.
Eg 3/8 - 10 tpi would be .375 -.1(10 tpi pitch distance for 1 pitch)=.275
However, this is not true for thread forms like the radial style , or the Southwest style of thread form.
But for the
5/16-18 tpi bore is .257 or a F drill,

5/16-14 tpi C drill or 6.1 mm

3/8-10 tpi 7mm drill or a J


Neil
Click to expand...
Wish I had known the formula a while back. I came up with the same drill sizes, but it was through trial and error. I do like to undersize the drill on a 3/8-10 to a G bit though, but that's a really tight fit. Thanks Neil, that's a drill formula worth writing down.

Alan
 
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