Determining drill bit size for a tap?
Thread Starter
Joined: May 2002
Posts: 2,620
Likes: 36
From: T56th Street, Aridzona
Re: Determining drill bit size for a tap? okay for 3/4-16 thread, it's an 11/16" bit
for 7/8-14 thread, it's a 13/16" bit.
any reason I woulddn't be safe w/ a 3/4" bit?
for 7/8-14 thread, it's a 13/16" bit.
any reason I woulddn't be safe w/ a 3/4" bit?
TECH Enthusiast
Joined: Nov 2001
Posts: 526
Likes: 0
From: Orange, TX
Re: Determining drill bit size for a tap? jmd:
A 20mm thread uses a 47/64" drill. Since 13/16 is slightly larger than 20mm, and 3/4" is slightly larger than 47/64" this further supports the use of a 3/4" drill.
A 20mm thread uses a 47/64" drill. Since 13/16 is slightly larger than 20mm, and 3/4" is slightly larger than 47/64" this further supports the use of a 3/4" drill.
Thread Starter
Joined: May 2002
Posts: 2,620
Likes: 36
From: T56th Street, Aridzona
Re: Determining drill bit size for a tap? Don on the Monte Carlo mailing list posted this nice link on bit sizes:
http://www.haascnc.com/Training/Hype...imal_Chart.pdf
http://www.haascnc.com/Training/Hype...imal_Chart.pdf
Re: Determining drill bit size for a tap? You may want to go slightly bigger than what the charts say in some cases depending on the material you're trying to tap. If it is something gummy like stainless steel, for example.
