Hand Tap or Drill Motor?

[Cadence]

A tap needs to be backed up every turn or two even in aluminum. A drill won't do that. A broken tap is a nightmare.

[Cheechako]

Originally Posted by Cadence

A tap needs to be backed up every turn or two even in aluminum. A drill won't do that. A broken tap is a nightmare.

That's true, although I've found on masts etc a drill works fine as the material is usually only 1/8"-3/16" thick.

[model 10]

Originally Posted by Cheechako

That's true, although I've found on masts etc a drill works fine as the material is usually only 1/8"-3/16" thick.

They have these cool bits now that have a drill and tap all in one. They work great on 1/8-3/16". You don't need to back up at all just blow through in one shot with your drill.

[TKDSailor]

One other thing you may want to do us use a form tap. Depending on the class of thread you want, your original hole is much bigger than a standard tapping hole, as the threads are "formed" not cut. Aluminum is perfect for this, and you have the added benefit of NO chips. BTW, 6-32 taps are the ones that break easiest, so go smaller or larger if you are using a cutting tap. For a 6-32 cutting tap, you use a .107 drill, but for a form tap we use the .125" dia drill size.

[TKDSailor]

For a 1/4" form tap, use .228" dia for 1/4-20, and .234" dia for 1/4-28 form tap. Do NOT use these drill sizes for a cutting tap- form taps only!

[jeepbluetj]

In the event of breaking off a tap and the subsequent major boogering of the hole you were trying to tap, what do y'all think about nutserts?

[Reefmagnet]

Originally Posted by jeepbluetj

In the event of breaking off a tap and the subsequent major boogering of the hole you were trying to tap, what do y'all think about nutserts?

Use helicoils. Seal with loctite. Super strong in a mast. Will snap the screw before they fail.

Sent from my SGP521 using Cruisers Sailing Forum mobile app

[Schooner Chandlery]

Lots of good pointers here. My husband taps by hand but I don't have the strength to do the tapping correctly if I'm also both steady and perpendicular to the material. It's an either or proposal--tap the metal and break off the tap whilst doing it or have it steady

Because of that, I have developed my own tricks over the years--first if it can be moved to the drill press, do so just to have the press hold the tap. Turn it by hand, but let the press do the holding. There's actually a little tap holder tool for letting you hand tap using the drill press as the holder (you can purchase from MSC, Grainger and the like) it just goes in the drill press, has a knurled surface you can grip and turn the tap with.

If tapping into something on-boat (or on-car engine or other large object) I have made simple jigs that prevent me from breaking off the tap while tapping. If a curved surface (like an aluminum mast) you will have to shape mating surface of the jig to the curved surface or use a curing material so you can come back and tap later.

Best of luck with it,
Brenda

[Mojadito]

Originally Posted by 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

The drill is by farther only way to go. I have broken more taps by hand then I ever have since using the drill. HappyMDsailors advice is right on the money with one addition. Use the correct size drill bit, if you are using one that is measured in fractions of on inch, it will be Wrong! Buy the "numbered" drill bit that the tap requires, it should be printed on the
tap.

[ernst]

Don't be scared to use the drill to Tap,I have tapped hundreds of holes with the drill over the years and the secret is only have the tap just tight enough in the chuck to hang on to it, if it grabs then it will slip, then reverse out a bit and go again. plenty of cutting compound and Bob's your Uncle !!

[Celestialsailor]

Originally Posted by 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.

Ah bull...If you don't try it, you won't learn. I've been a Machinist for 36+ years. It's called power tapping. If you're that sqeemish at first, use the screw clutch on the cordless drill. For cripes sake if you had to tap a mast by hand, you'd have carpal tunnel by the end of it. Use low gear and cutting oil and blow off the tap each time.

[boeing1]

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

[Reefmagnet]

When I used to install machinery years ago that would involve drilling and tapping up to hundreds of machine screws on site I would use a drill for tapping. It was unfeasible to do the work by hand. On the boat, I do most by hand excepting for 1/4" thick or more material and in that case, being lazy, I'll use the the cordless in many cases. I don't think I've broken a tap and not been able to extract it, but I always use the correct (or slightly oversize) drill bit specified for the thread, always use lubricant, always start off with the tapered tap, still do the 2 steps forward, one step back thing and, if not feeling especially confident, will start the thread by hand first.

A friend of mine is a freakish talent when it comes to doing things by hand and he can make perfect cuts of all shapes with a four inch angle grinder and runs around tapping holes with a cordless drill with nothing more than the occasional squirt of WD-40 and does it faster than I can screw the tap into it's holder. I guess it all boils down to experience.

[Cadence]

Originally Posted by Celestialsailor

Ah bull...If you don't try it, you won't learn. I've been a Machinist for 36+ years. It's called power tapping. If you're that sqeemish at first, use the screw clutch on the cordless drill. For cripes sake if you had to tap a mast by hand, you'd have carpal tunnel by the end of it. Use low gear and cutting oil and blow off the tap each time.

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.

[Blue Crab]

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