8-40 Tap

[Edd]

I would like to buy a good quality 8-40 bottom tap. I can find them priced from $6 to $60. Does a person have to spend $60 to get a good one?

 

[DRK]

I always have used carbon steel taps, aka the cheap ones, for drilling & tapped scope mounts. If you break one, it is a lot easier to remove it than a harder one.

 

[Doug Beach]

McMaster Carr has a US made HSS 8-40 bottoming tap for $26.25. It’ll work fine.

 

[gunsandgunsmithing]

I always have used carbon steel taps, aka the cheap ones, for drilling & tapped scope mounts. If you break one, it is a lot easier to remove it than a harder one.

Same here. Even if you buy a new one every couple of holes. Hss lasts longer, unless you break it. That is when it bites and they break just as easily.

 

[AlNyhus]

The Sandvik-Coromant spiral fluted ones are my favorite...but they've dc'd the 8-40 size.

The ones from MCS's 'Value Collection' have done a very good job too. I'm a total chicken shit when it comes to breaking a small tap so I don't press my luck for doing too many holes without a fresh tap....there's a bunch in my drawer with only 8 holes on 'em.

A hand tap guide in the 1/2" collet, some moly cutting oil, clean the threads often and a fresh cup of coffee works for a hacker like me.

 

[Jonnyofalltrades]

The Sandvik-Coromant spiral fluted ones are my favorite...but they've dc'd the 8-40 size.

The ones from MCS's 'Value Collection' have done a very good job too. I'm a total chicken shit when it comes to breaking a small tap so I don't press my luck for doing too many holes without a fresh tap....there's a bunch in my drawer with only 8 holes on 'em.

A hand tap guide in the 1/2" collet, some moly cutting oil, clean the threads often and a fresh cup of coffee works for a hacker like me.

Second for those spiral flutes taps. They are amazing!
I've always wondered if they're stronger or weaker than a straight flute, but I'm too chicken to find out.

 

[AlNyhus]

Second for those spiral flutes taps. They are amazing!
I've always wondered if they're stronger or weaker than a straight flute, but I'm too chicken to find out.

I love 'em for aluminum...evacs the chips nicely and makes me look like I've got a clue.

 

[Alex Wheeler]

When I still did the 8-40 upgrade on 700 actions I tried a bunch and the ones from brownells were the best.

 

[Alex Wheeler]

Also, moly-d is your friend and throw the tap away after one job. They are cheap enough and when they dull they break.

 

[gunsandgunsmithing]

When I still did the 8-40 upgrade on 700 actions I tried a bunch and the ones from brownells were the best.

At one time I heard who made them for Brownells but I've slept since then. Lol! But I agree, they are good and all I've had from them were plain ol carbon steel taps. I used to buy them several at a time in each size. I do think just being sharp means a lot in our application and they're cheap enough to just use one for a job and toss it. A worn out tap is expensive and a PITA. Production work is a different story, as is the material. HSS is very good for most stuff but for gun work and small blind holes, it's tough to beat a sharp carbon steel tap. WHEN ya break one, it's a good bit easier to get out without an edm to burn it out. That's the biggest thing, really. I've drilled them out several times, using carbide to drill carbon steel. HSS can be cut be carbide but it's a big step up in that regard. Carbide sounds great but sucks for a small tap. I's best for aluminum production work, where little strain is involved and keeping a sharp edge for several parts is key.

 

[Alex Wheeler]

I think the ones I had said regal on them.

 

[paperpuncher]

Also, moly-d is your friend and throw the tap away after one job. They are cheap enough and when they dull they break.

Sage advice for sure... when the tap starts squealing youre playing with fire

 

[gunsandgunsmithing]

I think the ones I had said regal on them.

May be. Doesn't sound like I was thinking but I don't doubt you're right.

 

[whatsupdoc]

I have used the Reiff & Nestor taps, I believe that is what Brownells sells but I think I
bought them on fleabay.

 

[LVLAaron]

I like Hertel or Interstate. Tap 4 holes and toss'em.

 

[paperpuncher]

The last 6-48 taps I bought locally was like tap 1 hole toss it lol They were crap taps

 

[hogpatrol]

I use three flute gun tap ground to suit. McMaster Carr sells them.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[std7mag]

We use a lot of the Hertel taps at work.
Love the spiral taps that twist to bring the chips up!!
The ones that push them down, suck!!

Definitely agree with having a sharp tap!!
We definitely do more than 3-4 holes with ours.
Clean after each hole with some compressed air.
Lube is your friend!!

Rapid Tap for normal duty.
Large taps, and hard material get moly.

 

[Jonnyofalltrades]

Four holes and toss?! Wow.
Anything a little odd like UNS taps is a pain to source up here. I've lost count of the jobs done with some of my taps.

 

[ebb]

I have always had my best luck with Gunn 2 fluted taps.