Drilling and Tapping for the first time - help! - The Firearms Forum

mookiie · 02-23-2012, 10:30 PM

All,
I am drilling and tapping an SKS reciever for the first time. I plan to use a drill press to drill the wholes. It is a square receiver so it should be easy to clamp. Can anyone with more experience give me some pointers?
Thanks,
Sean

jack404 · 02-23-2012, 10:46 PM

to help tap straight you can use a peice of old thong ( flip flops i think in the USA )

drill a millimeter or so undersize and tap through that with lots of oil ..

Zane71464 · 02-23-2012, 10:54 PM

...I might add, to be sure and set you drill press stop at the right depth
you intend to drill. (for the right screw depth)
And welcome to the forum!

Bindernut · 02-24-2012, 12:30 AM

Also, when laying out your holes make sure you get them centerlined to the receiver so that the scope mount is as close to your zero point as possible.
Tapping for a side mount on an SKS, you're not really going to have a problem with the windage, but yif the holes get off track your elevation may be too far off to dial in your zero with the scope's adjustment.

To get holes tapped straight, most of the time I use the drill press.
I chuck the tap into the drill and turn the chuck by hand (do NOT use the motor!

)
Usually, I will tap each hole right after I drill it and before I move onto the next hole. That way you don't have to re-center the work under the tap...small taps don't take very much side-stress before they snap off.

Break your chips frequently (Do a tiny turn, then back off. Another tiny turn, then back off, repeat as needed.) If you cut too big of a chip, it'll curl around inside the flutes of the tap and jam it up...and snap off.

Use the right size drill bit for the screw/thread size you're cutting.
Google search for "tap/drill size chart".
There is a very complete one on Wikipedia, but it's not a handy one to download or print out. http://en.wikipedia.org/wiki/Drill_and_tap_size_chart
Lots of them out there that will cover any size hole that you'll be tapping.

Charles Christensen · 02-25-2012, 03:58 PM

Get a piece of scrap metal of the same type and drill and tap 100 holes before you touch the gun.

76Highboy · 02-25-2012, 04:01 PM

Quote:

Originally Posted by Charles Christensen

Get a piece of scrap metal of the same type and drill and tap 100 holes before you touch the gun.

Words of wisodm.

Gabob · 02-25-2012, 07:53 PM

The only SKS I drilled and tapped was very easy. It did throw some spectacular crimson sparks when I was drilling it. Looked like a Strontium flame test from chemistry lab. I have drilled and tapped lots of metal but never seen anything like that.

02-23-2012, 10:30 PM	#1
mookiie Member Join Date: Feb 2012 Posts: 1	Drilling and Tapping for the first time - help! All, I am drilling and tapping an SKS reciever for the first time. I plan to use a drill press to drill the wholes. It is a square receiver so it should be easy to clamp. Can anyone with more experience give me some pointers? Thanks, Sean -->

02-23-2012, 10:46 PM	#2
jack404 Former Guest Join Date: Jan 2010 Location: Australia Contributor Posts: 17,622	Re: Drilling and Tapping for the first time - help! to help tap straight you can use a peice of old thong ( flip flops i think in the USA ) drill a millimeter or so undersize and tap through that with lots of oil ..

02-23-2012, 10:54 PM	#3
Zane71464 Advanced Senior Member Join Date: Aug 2009 Location: Ohio NRA Member Contributor Posts: 5,415	Re: Drilling and Tapping for the first time - help! ...I might add, to be sure and set you drill press stop at the right depth you intend to drill. (for the right screw depth) And welcome to the forum! __________________ Two Words; "Simple Man", song by Charlie Daniels sums up my thoughts on a "few things"!

02-24-2012, 12:30 AM	#4
Bindernut Advanced Senior Member Join Date: Oct 2007 Location: ND, USA Posts: 2,489	Re: Drilling and Tapping for the first time - help! Also, when laying out your holes make sure you get them centerlined to the receiver so that the scope mount is as close to your zero point as possible. Tapping for a side mount on an SKS, you're not really going to have a problem with the windage, but yif the holes get off track your elevation may be too far off to dial in your zero with the scope's adjustment. To get holes tapped straight, most of the time I use the drill press. I chuck the tap into the drill and turn the chuck by hand (do NOT use the motor! ) Usually, I will tap each hole right after I drill it and before I move onto the next hole. That way you don't have to re-center the work under the tap...small taps don't take very much side-stress before they snap off. Break your chips frequently (Do a tiny turn, then back off. Another tiny turn, then back off, repeat as needed.) If you cut too big of a chip, it'll curl around inside the flutes of the tap and jam it up...and snap off. Use the right size drill bit for the screw/thread size you're cutting. Google search for "tap/drill size chart". There is a very complete one on Wikipedia, but it's not a handy one to download or print out. http://en.wikipedia.org/wiki/Drill_and_tap_size_chart Lots of them out there that will cover any size hole that you'll be tapping.

02-25-2012, 03:58 PM	#5
Charles Christensen V.I.P. Member Join Date: Nov 2011 Posts: 208	Re: Drilling and Tapping for the first time - help! Get a piece of scrap metal of the same type and drill and tap 100 holes before you touch the gun.

02-25-2012, 07:53 PM	#7
Gabob Advanced Senior Member Join Date: Dec 2005 Location: SW GA CSA Posts: 1,162	Re: Drilling and Tapping for the first time - help! The only SKS I drilled and tapped was very easy. It did throw some spectacular crimson sparks when I was drilling it. Looked like a Strontium flame test from chemistry lab. I have drilled and tapped lots of metal but never seen anything like that. __________________ NRA Endowment Member Keep Your Powder Dry