Gunsmithing So A #8-40 Thread Tap Is Apparently Rare As Hens Teeth.

[Steel+Killer]

I got a really good deal on a slightly used 24" Benelli Super Black Eagle barrel that I wanted for turkey hunting and I use a red dot sight for turkey hunting so I wanted to put a base on it, but this barrel was a gen 1 that didn't come drilled and threaded like the SBE2 and newer barrels do. So I did a little research and found I needed a #8-40 thread tap for the new picatinny base I am wanting to install on it. Trying to find a #8-40 tap locally is like trying to find plutonium locally.........impossible......why is it always the one little tool I need always that odd ball thing hard to find.....LOL

 

[Rubicon Precision]

Around the house, probably pretty rare. In the gun world, 8-40 is pretty common. Order one from Brownells.

 

[Alabusa]

Check and see if you have a machine tool supplier local to you. They will probably have one in stock.

 

[Steel+Killer]

Around the house, probably pretty rare. In the gun world, 8-40 is pretty common. Order one from Brownells.

I ordered one off Amazon......I know I should be supporting company's like Brownells, but damn Amazon makes it so damn easy. I do support company's like that for big ticket items though.

 

[PatMiles]

Small items such as an 8-40 tap, I order a couple maybe 3. Cheap enough to have spares. They do get lost, dull or break.

 

[Waorani]

When the cheap Amazon tap breaks, McMaster Carr has them.

 

[Threadcutter308]

Pretty much all local hardware stores/chains don't carry NF taps, only NC........

 

[flyer]

Local hardware stores are usually crap. There is one Ace hardware that surprises me from time to time but other than that I have to order online or go to a real industrial supply shop which can usually get whatever I need within a day (but not cheap).

 

[LRI]

With taps you get exactly what you pay for.

Read that over and over again and burn it into your hard drive. It'll save you a whole lot of mental yeast infection.

Avoid the "dollar stores" online. A supplier I use with great success is Cutting Edge Tool in Colorado Springs, CO. Ask for Kevin.

-Be sure to tell him you got his name off a bathroom stall at a truck stop.

Good luck.

 

[flyer]

I have to agree, when tapping in to hardened steel, metals that gall easily or gummy materials, get the best tap you can find.

On the other hand for aluminum threads (coarse usually) or chasing existing threads, a cheapo will usually work.

 

[Steel+Killer]

Damn now I am thinking I should have just dropped it off at my local gunsmith, but I like doing stuff myself. Also if this was a precision rifle I would definitely not be trying to tap this myself, but I figured a red dot on a shotgun barrel I could get away with it......lol

 

[...]

When the cheap Amazon tap breaks, McMaster Carr has them.

if you were tapping more than 1 or 2 holes......it makes sense to buy a quality tap.

but im not about to spend $30 on mcmaster when a $5 tap from amazon will get the job done just fine.

 

[flatland1]

One of the first projects I did after buying my JET knee mill was to build a stainless front rest from plans that the original designer let me use to make one for myself. I'd seen a review of this rest in Precision Shooting back in the late '90s IIRC, and always thought it was something I'd like to make for myself if & when I bought a lathe & mill. Anyway, I'd bought a bunch of surplus stainless at The Yard in Wichita, and no one there really had a clue what alloy the different pieces they had in stock were - I asked, they gave me a magnet. Guess that's how you tell 300-series from 400-series SS in a surplus/salvage yard. I got enough stainless to build two of these rests for about $45...try finding a deal like that today. Quickly learned not to peck at 316 - have your cutting oil ready, and plunge right on in there! That stuff work-hardens like nobody's business. Also learned the truth in what Nesika Chad/LRI said earlier in this thread - "When it comes to taps, you get what you pay for." Truer words were never spoken. I started buying Cleveland gun taps (also known as spiral point taps) when I got into this BR rest project, and have never looked back. I'm not saying that Cleveland taps are the top-of-the-heap quality, but they're head & shoulders better than the Hanson taps most auto parts stores carry. I've bought a few R&N taps in 6-48 & 8-40 over the past few years, and they're also better quality than most of the stuff that Brownells carries. MSC, McMaster-Carr, K&N, MariTool - those are some of the places I look when I'm buying taps. This isn't a good photo of the rest, but it's what I had, with a trued M700/Bartlein hvy Palma 6 Dasher in a Shehane tracker stock done in Indian Paint obeche stock. Rest weighs 26lbs, and I did all the knurling & threading on the lathe.

 

[MarinePMI]

https://www.brownells.com/search/index.htm?k=8-40+tap&ksubmit=y

Not sure who makes Brownells' these days, as it's been awhile since I ordered gun specific taps, but they used to be of pretty good quality.

That being said, I'd recommend listening (strongly) to what Chad said. Nothing makes a job harder, and more miserable, than shitty tools. Most hardware store and dollar store taps are designed (and hardened, if you can call it that) to chase existing threads, not tap new ones.

Also, be sure you know what type of tap you need (plug, bottoming, spiral cut etc.). It'll save you a lot of headaches to order a bunch at one time, and as many of the types as you can afford for their various tailored applications (blind hole, through hole, starter etc.).

A broken tap extractor and good tapping fluid are also some wise purchases as well.

 

[LRI]

if you were tapping more than 1 or 2 holes......it makes sense to buy a quality tap.

but im not about to spend $30 on mcmaster when a $5 tap from amazon will get the job done just fine.

A dangerous assumption: "get the job done just fine..."

I'm sounding like an ass, I don't mean to. It's just that "hold my beer and watch this shit" often ends poorly. For me it does anyway.

Price this out:

Cost of barrel.
Cost of shipping.
Cost of mental anguish when you have to wait.
Cost of now having it fitted, finished, tested.

Even better yet:

Murder the cheapo and now take it to a guy like me who charges an hourly rate to try and remove it forensically and tells you up front its a 50/50 chance on whether or not it machines out cleanly.

By anyone's barometer, $30 is a bargain.

FWIW, good taps, start at around $40-$45 bucks a piece. Whenever possible I avoid taps and thread mill. Them little buggers run north of $80 each. My .120" dia ones for 8-40's are over $100.

As mentioned, you get exactly what you pay for. Doing it once or 100+ times doesn't matter if the material condition isn't accounted for.

Best of luck.

 

[hermosabeach]

https://www.mcfaddendalehardware.com/

If you have not found all of the Awesome hardware stores in your area... There are some great ones within about an hour drive for me...

if the part I am working on can be easily replaced, some household project, cheap taps are good...

If I need to hire someone with an EDM set up to remove my tap... high quality

 

[timesublime]

On the other hand for aluminum threads (coarse usually)

Aluminum taps are usually three fluted.

 

[flyer]

Well that entirely depends on the size and form taps have zero flutes.

On the topic of good tapping fluid, any kind of decent oil seems to do ok on Aluminum, I like Castrol Moly-Dee or Moly-d for just about everything else, it stinks and it's worth it.

 

[gunsnjeeps]

A five dollar tap for one hole is usually the one the gunsmith pulls out of the hole.

 

[LRI]

Well that entirely depends on the size and form taps have zero flutes.

On the topic of good tapping fluid, any kind of decent oil seems to do ok on Aluminum, I like Castrol Moly-Dee or Moly-d for just about everything else, it stinks and it's worth it.

On the cheap, ATF cut with some acetone works really well in AL also.

 

[timesublime]

ATF cut with some acetone works really well.

Yep, and it is an excellent rusted bolt release agent. (aka break free)

 

[tlsmith22]

Its a common size screw that electricians use. Any electrical supply house should have one.