Hand Tap or Drill Motor?

[Blue Crab]

My own very limited experience has been to use the proper drill bit and tap the holes by hand.

My buddy, the expert, uses taps in his drill motor. Bingo he's finished but it seems risky when you don't want to bugger up.

What's the pro way? I need (8) 1/4" holes for fine thread machine screws.

Thanks

[Reefmagnet]

8 holes? Not confident? Do it by hand. Having said that, a cordless drill makes a great tapping machine and it isn't that hard to use. Just make sure that you use cutting lubricant, cut at a sensible speed and whatever you do don't cross thread (i.e. take extra care starting the thread). Also don't bottom out in a blind hole at speed!

[HappyMdRSailor]

Wassup Crabby my man!

Oh ... for sure you can tap with a motor... With a bunch of caveats:

1. Depends on what your tapping... Soft Al on the easy side of the spectrum, Hard SS on the other...

2. If this is your first foray into it... 1/4 should be the tiniest you try... 6/8/10/12 are easier to snap...

2A.... The most important learning step is to keep the lateral movement of your drill motor to ... well, none..... Or snappy-snappy

3. Have a DECENT motor... Ace Skill ain't the way to go here... Power&chuck= suck.... Nor is overkill... A Porter Cable 1/2" is going to have TOO much torque and run on.. (past where you want to stop=broken tap) Dewalt is perfecto...

4. Sharp tooling and lotsa lube

5. You won't bugger it.... small trigger pull until she gets resistance, about 1-2 turns, reverse 1/4 turn, forward-reverse-forward-reverse... You can back all the way out and clean your tap/relube after you have a few turns in...

Easy peasy really... 8 predrilled holes in 1/4" Al plate = 3 minutes

[paulajayne]

Tapping with a drill is wrong -


Have to ever tried to remove a broken tap - plus the thread form will be poor.


Taper - second and plug taps in that order.


Do it by hand, keep it oiled, 1/2 turn in and 1/4 turn back will produce a much better thread.

[HappyMdRSailor]

Or you can bring yer boat over... We'll flip her on her beam end, slap her on the mini-mill and show who's boss with the Tapmatic....

https://www.youtube.com/watch?v=hmaX...ature=youtu.be

[sartorst]

Having the proper drill size is important. This usually requires a drill index ,Not thats about right, I have done it many times into aluminium , the first one is done by hand to tell how much load ,twist ,flex,etc, if I'm not happy may go up a size drill bit

[Delancey]

Unfortunately it's hard for flesh to mimic a machine, which is what the pro's use. A tapping machine. Pro's don't tap by hand. Agreed with Happy's comments.

Would only add that the non-pro's best bet is a cordless drill with a clutch. Start out on the lower end and work your way up. Less chance of snappy snappy. Also, never hurts to practice on some scrap. Practice makes perfect!

[HappyMdRSailor]

Originally Posted by Reefmagnet

Also don't bottom out in a blind hole at speed!

+1

Originally Posted by sartorst

if I'm not happy may go up a size drill bit

+0.825 (depends on the application)

Originally Posted by Delancey

Would only add that best bet is a cordless drill with a clutch. Start out on the lower end and work your way up. Less chance of snappy snappy. Also, never hurts to practice on some scrap. Practice makes perfect!

Like both of the D-man's suggestions.... clutch and scrap...

Plus whatever you're tapping into... If it's going to be the worst mistake you ever made snapping a tap... like in a blind hole in an engine block... nooooooo.....

Where the hell did crabby go...

[Blue Crab]

Yeah, I'm not confident. I'm sticking with the old reliable hand job. The work is in the mast. I'm imagining a short scaffold on sawhorses I can lay on to help with the perpendicularity.

While alum, I'm guessing it's harder than a hunk o' metal from Ace Hardware. I was also going to use 1/4 -20; the same that came out, but a search revealed a Delmarry post where he suggested this was a case for fine threads where there wasn't much depth involved, and to use the next size down drill bit to get 100% threading, as mentioned above, so I'm off to Fastenal this morning. Of course coarse there is a case to made that the 1/4 - 20 was OK for 39 years.

As a sidebar, the expert and I were both amazed that all 8 machine screws came out intact using an impact wrench with Phillips bit! Corrosion dust was flying. I had no luck at all with my Chinese hand-held impact driver.

Happy MdR: Maybe I'll just drop the mast and Fed Ex it to you and yer fancy machine. [Maybe "dropped" isn't the correct verb here.]

Thanks folks!

[Matt Johnson]

I've done just over 500 machine screws into the aluminum frame of our boat so far. All while using a combination drill and tap bit.... couldn't have done it any other way. I've broken 6 so far.

http://www.amazon.com/Greenlee-DTAP1...ap+combination

Matt

[Tellie]

If you are going to use a drill motor for the first time to tap. The best advice is to practice first. Eight holes are too few to try to make fast work of it.

[HappyMdRSailor]

Originally Posted by Blue Crab

Yeah, I'm not confident. I'm sticking with the old reliable hand job. The work is in the mast. I'm imagining a short scaffold on sawhorses I can lay on to help with the perpendicularity.

While alum, I'm guessing it's harder than a hunk o' metal from Ace Hardware. I was also going to use 1/4 -20; the same that came out, but a search revealed a Delmarry post where he suggested this was a case for fine threads where there wasn't much depth involved, and to use the next size down drill bit to get 100% threading, as mentioned above, so I'm off to Fastenal this morning. Of course coarse there is a case to made that the 1/4 - 20 was OK for 39 years.

As a sidebar, the expert and I were both amazed that all 8 machine screws came out intact using an impact wrench with Phillips bit! Corrosion dust was flying. I had no luck at all with my Chinese hand-held impact driver.

Happy MdR: Maybe I'll just drop the mast and Fed Ex it to you and yer fancy machine. [Maybe "dropped" isn't the correct verb here.]

Thanks folks!

Oh man... Delancy told me I was kickin' it old school... But ya one upped me with the Old school hand job... (never mess with the master)

You're going the right route here crabster... Anything that isn't solid between you and the deck (concrete floor and a vise) is subject to severe disappointment attempting this on a large learning curve...

1/4-28 is the way to go in a stick... btw... fine thread taps add to the difficulty factor of using a drill motor... just more "feel force" one would need familiarity for...

Make sure you grab a few new sharp bits your required size 0.213 (1/4-28) and above 0.218 (7/32) Extra tap, Tapping fluid for Al...

It's ALWAYS nice when fasteners come out... Go buy a lottery ticket on your way to Fastenal....

Sure! drop that stick in the post ... We'll get 'er dun !

Or alternatively... You can come by and help me with my project...

[HappyMdRSailor]

Originally Posted by funjohnson

I've done just over 500 machine screws into the aluminum frame of our boat so far. All while using a combination drill and tap bit.... couldn't have done it any other way. I've broken 6 so far.

http://www.amazon.com/Greenlee-DTAP1...ap+combination

Matt

Good tool for mass production... = 500 holes! Not for precision work tho...

Originally Posted by Tellie

If you are going to use a drill motor for the first time to tap. The best advice is to practice first. Eight holes are too few to try to make fast work of it.

He's already committed to the hand job, but Tellie's right on here... By the time you learn the feel for it... Taking breaks to wipe you brow... 8 holes would be done by hand...

[Blue Crab]

That's the 'Merican way fo shore! Thanks for all the help guys. I will crow with happiness if it works out the first time. If not, I'll slink away silently.

[paulajayne]

Does not " A hand job" mean the same in the States as it does in the UK?