First facing cut - carbide insert - 5/8" brass round

[ssdesigner]

Sort of. That would probably work, but if you notice, it has "H4" in the description which means it's slightly oversized....the higher the number the more oversized they are and each number overlaps in tolerance. The tapping world can be a rabbit hole with many subtle differences.

I've been buying US made taps off eBay from a seller here in Michigan with good luck. I just bought a 2-pack of 3/8-24 and they're nicely made....H2 so only a tiny bit oversized.

Morse 3/8-24 STI Bottoming Tap HSS H2 4 Flute Taps 2 Pack 34077 | eBay

MORSE CUTTING TOOLS. H2 - 4 FLUTE - HIGH SPEED STEEL.

www.ebay.com

Purchased the 3/8" 24 H2 and the tap completely fu*&^%$ my scribe cap. This tap measures .469" vs. the .369" tap I used on this part originally. The threading is nowhere near the same.

Wow. I'm speechless. And I'm remaking my cap tomorrow I guess.

 

[G-ManBart]

Purchased the 3/8" 24 H2 and the tap completely fu*&^%$ my scribe cap. This tap measures .469" vs. the .369" tap I used on this part originally. The threading is nowhere near the same.

Wow. I'm speechless. And I'm remaking my cap tomorrow I guess.

Oh man, that's terrible...they must have sent the wrong tap. I've gotten a bunch of different sizes from them and they'll all be exactly what I ordered. How are the taps themselves marked?

 

[piper184]

Ah, your first "do over". Welcome to machine work. Well, any form of shop work really.
Maybe it is time you tested the waters for single point threading?

 

[ssdesigner]

Oh man, that's terrible...they must have sent the wrong tap. I've gotten a bunch of different sizes from them and they'll all be exactly what I ordered. How are the taps themselves marked?

They are marked 3/8 24 H2, but I could throw a 3/8” bolt through a hole created by these taps.

Does it make any sense at all that my calipers measure these at .469” wide? Am I missing something here?

 

[ssdesigner]

Ah, your first "do over". Welcome to machine work. Well, any form of shop work really.
Maybe it is time you tested the waters for single point threading?

If I can help it, I’ll wait a while before I do any threading where a tap and die isn’t a part of the process. I have a small list of starter projects that I want to work through, and none of them involve messing with gears and maths to cut threads.

 

[G-ManBart]

They are marked 3/8 24 H2, but I could throw a 3/8” bolt through a hole created by these taps.

Does it make any sense at all that my calipers measure these at .469” wide? Am I missing something here?

That's crazy....definitely doesn't make sense at all. That has to be some kind of mixup in production for them to be that far off. I can only imagine how frustrating the would be!

 

[piper184]

What kind of reading do you get from your caliper when you check the original tap that you used?
If that measures correctly then this tap must be marked wrong.
Hopefully you can return it and get the correct tap.

I hear ya on single point threading. Any time a tap or die will do it is much easier, even when you have a QCGB. BUT, it is a valuable skill to have and sometimes it is easier to learn a new skill then to spend $$ and time waiting for shipping.

At least it was the cap and is the least intense part of your project.
Hope you get it sorted out all OK.

 

[ssdesigner]

What kind of reading do you get from your caliper when you check the original tap that you used?
If that measures correctly then this tap must be marked wrong.
Hopefully you can return it and get the correct tap.

I hear ya on single point threading. Any time a tap or die will do it is much easier, even when you have a QCGB. BUT, it is a valuable skill to have and sometimes it is easier to learn a new skill then to spend $$ and time waiting for shipping.

At least it was the cap and is the least intense part of your project.
Hope you get it sorted out all OK.

The original tap is .369”

 

[ssdesigner]

That's crazy....definitely doesn't make sense at all. That has to be some kind of mixup in production for them to be that far off. I can only imagine how frustrating the would be!

I have been a maker for 30+ years so I’m definitely not a stranger to rework, but I still hate it. I plan ahead and overthink things and generally avoid rework, so yeah, this is pretty frustrating. All part of the learning curve though, so there’s that.

 

[ssdesigner]

I was a little off on my measurement of the new tap. It’s .433” wide. See pic