Tap Tap

[wheelinround]

I have a project I am doing and I want to Tap a thread through 6000 series Ali ok not a problem normally but its 2" thick most taps won't go through that far.

Does anyone know of where longer Taps are available?

[pipeclay]

Just do a google search,Bolt have them for starters,depending on the size and form,they wont be cheap,try ebay.

[BobL]

What size tap and what sort of precision are you looking at?

For anything above 8 mm you can just make 2" with a standard bottoming tap, start with a tapered tap and then switch to a bottoming tap.

If it does not have to be super precise, for smaller than 8mm diamn I have made my own taps down to 5 mm from a tensile steel bolts by grinding a groove usinhg a thin kerf grinding wheel along the shaft in 3 places. Start with a a regular tap and when you have gone as far as you can switch to the home made jobbie. For 4 and 3 mm threads I just grind a tapered triangular point on the end of the bolt, and stop, withdraw and clear the thread often using a compressor. I use a small cordless drill to turn the taps and set the clutch according. I have tapped 3" long threads in ally this way.

Don't forget to use meths as a lube.

[Claw Hama]

Isn't the shank on a tap smaller than the thread anyway? or am I having moment?

[Dave J]

Isn't the shank on a tap smaller than the thread anyway? or am I having moment?

No, not a moment, thats what I was thinking as well. I have also welded a extension on the end for a few jobs. It can be cut off when your finished so you don't bugger the tap.
As said above if it's bigger tap it should make it through.

Dave

[Gavin Newman]

The other thing to consider is whether you really need all 2" threaded to handle the loads expected, it may be possible to thread an inch or so and clearance drill the rest of the depth.

[wheelinround]

:2tsup: Thanks all some top ideas here.

Thread size will be 1/4" or larger.

No not all Taps are smaller than thread area I have had this problem often over the years smaller threads mainly.

Bob like the idea of using the converted bolt.

1" will be adequate for threaded area so the train of thought is OS the rest :2tsup:

[pipeclay]

If its any use I can lend you 5/16 bsw,3/8 unc,7/16 bsw,1/2bsw long series taps.

[Kody]

shop around for the taps that are used for making standard nuts. The threaded section is the normal length but the tap body is such that the nuts are lifted up in a continual feed. I haven't seen one of these or the machines that tap them for many years. You can buy extra long series taps for deep holes. I highly recommend that you use "Bullet" style taps for such deep holes and use "Tap Magic" as a lubricant. The bullet taps can be wound in non-stop using Tap Magic as the thread chips are pushed forward and out of the hole.
Kody :2tsup:

[wheelinround]

If its any use I can lend you 5/16 bsw,3/8 unc,7/16 bsw,1/2bsw long series taps.

Pipeclay generous offer :2tsup: thanks but no need.