Hand Tap or Drill Motor?

[Reefmagnet]

Originally Posted by Blue Crab

How many of you would make a jig? This is dealing with the curvature of the mast per Brenda's comment.

I have to confess I've snapped bolts in the mast when screwing down cleats (that are thick and use long bolts) because my thread (well, drilled hole tbh) was cock-eyed slightly. With thinner material to pass bolts through, or larger hole to screw clearances this problem diminishes. If you need accuracy and don't have "boilermaker's eye" then a jig would be a great idea, I reckon.

[Celestialsailor]

Originally Posted by boeing1

what do you want a fast job or a good one, I would go by hand to tap...

It is both for drill tapping. You use 2 hands and can hold it much more steady than hand tapping. Your hand does not twist in a uniform way. The tap hole is way blown out at the start of the thread. A go/no go gage proves this. Drill tapping is much more uniform.

Originally Posted by Cadence

I don't believe he was speaking of something as thin as a mast? Sounded more like plate? I haven't been a machinist for all those years. Are you sure you are not speaking of self tapping machine screws? I'd pop a hole and run one in in a minute with a clutched drill.

Today, I just drilled and 1/4-20 tapped 3/4" cast iron. It's easier than you would think. For Aluminum, I use A9 tapping fluid and Rapid Tap for general cutting and tapping steels and Aluminum.
Reading all the negatives about drill tapping appears to be people that have not tried it.

[Cadence]

Originally Posted by Celestialsailor

It is both for drill tapping. You use 2 hands and can hold it much more steady than hand tapping. Your hand does not twist in a uniform way. The tap hole is way blown out at the start of the thread. A go/no go gage proves this. Drill tapping is much more uniform.



Today, I just drilled and 1/4-20 tapped 3/4" cast iron. It's easier than you would think. For Aluminum, I use A9 tapping fluid and Rapid Tap for general cutting and tapping steels and Aluminum.
Reading all the negatives about drill tapping appears to be people that have not tried it.

What do you us for stainless?

[Delancey]

Originally Posted by Celestialsailor

You use 2 hands and can hold it much more steady than hand tapping. Your hand does not twist in a uniform way....
....Reading all the negatives about drill tapping appears to be people that have not tried it.

What he said.

[model 10]

Originally Posted by Cadence

What do you us for stainless?

I had to do a bunch of holes in stainless and found a new wiz bang tapping fluid for stainless.. It's a bit messy as it's black and oily. You won't believe it till you try it. There was no galling to speak of.
It's called Moly Dee cutting fluid.

[Celestialsailor]

Originally Posted by Cadence

What do you us for stainless?

Originally Posted by Guy

I had to do a bunch of holes in stainless and found a new wiz bang tapping fluid for stainless.. It's a bit messy as it's black and oily. You won't believe it till you try it. There was no galling to speak of.
It's called Moly Dee cutting fluid.

Moly Dee


By the way, I can drill tap 303 or 304. But that I will admit, you have to be very careful.

[Hard Rock Candy]

I do not believe that anyone has mentioned that there are machine taps and hand taps. The hand taps have straight flutes, four in number. the machine taps have just two straight flutes and are a lot stronger than a four flute tap. For stainless I use a mixture of kerosene and bees wax. for aluminum I use Rapid tap. I believe it is made for aluminum. If you cannot start the tap perfectly straight with the hole the tap will be cutting more on one side than on the other and is a quick way to break the tap. Mac

[a64pilot]

A few have brought up the difference in a machine vs hand tap, but to me using a drill to tap is just wrong, like using a hammer to install screws, yep it's fast, you can get done in a hurry, but it's just wrong.
But many, many machine shops and almost all manufacturing use machines to tap, so it is possible and obviously if the right feed and speed and tool is used it works well, but so far as going to my tap set that I have had since I was 16 and chucking one in a rechargeable drill? No way.


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[Reefmagnet]

If you live on the boat and can't carry everything, Lanolin has a zillion and one uses and being a half decent cutting lubricant is one of them.

[model 10]

Originally Posted by Reefmagnet

If you live on the boat and can't carry everything, Lanolin has a zillion and one uses and being a half decent cutting lubricant is one of them.

Here is another use of lanolin. Every time my wife smells my tub of Lanocote she says she thinks of nursing her kids. Apparently you use lanolin on your nips while nursing.

[deblen]

Would these be a good substitute for tapping?
They come in different styles.

Stainless Steel Blind Jack Nut 1 4 20x0 71" | eBay

[a64pilot]

Lord no, those things are for use in drywall and that kind of thing, but does bring up "rivnuts". I hate those things with a pashion, what happens is the screw binds in the rivnut, and the rivnut spins in whatever it is shot into, so your screw is now a rivit, sometimes needing a drill to get it out.
Now a Helicoil actually adds strength, is more work and expense, but strong, and your stainless steel screw is screwed into a stainless steel helicoil
Way back when I was drag racing KZ-900's once you got the motor making lots of power, the engine case halves would pull apart as the bolts would literally be pulled form the aluminum case halves, drilling them out and installing helicoils stopped that.


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[Celestialsailor]

Originally Posted by a64pilot

A few have brought up the difference in a machine vs hand tap, but to me using a drill to tap is just wrong, like using a hammer to install screws, yep it's fast, you can get done in a hurry, but it's just wrong.
But many, many machine shops and almost all manufacturing use machines to tap, so it is possible and obviously if the right feed and speed and tool is used it works well, but so far as going to my tap set that I have had since I was 16 and chucking one in a rechargeable drill? No way.


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No offense...reading this leans me to believe that you have not tried it. Why base an opinion on what you think will happen? I and thousands of people in all kinds of professional trades do this.
Tapping by hand is like a hammer on the threads.

[Cap Erict3]

TEK screws have a bit, tap, starter threads and threads. Even if you swap them out for other screws, they make drilling and tapping a snap.

https://www.fastenal.com/products/fa...0Screws%22%7C~




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Looking for another pretty place to work on the boat.

[HopCar]

Mr. Thomas, my high school shop teacher would have smacked my butt with a big paddle if I had chucked up a tap in a drill. I'm sure he's long dead so I may try it.
Do you reverse the drill every so often to break the chip?