Drill and Tap Chart

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.
 

dave sutton

Banned
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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BHQ

we'll miss you
Silver Member
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
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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BooBoo

AzB Silver Member
Silver Member
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.
 

conetip

AzB Silver Member
Silver Member
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
 

dave sutton

Banned
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.


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
 

aphelps1

Phelps Custom Cues
Silver Member
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
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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