00-90 cutting tap versus forming tap

[Chris333]

I don't know if it's good or bad, but we use this stuff at work on all taps:
https://anchorlube.com/product/anchorlube/

[peteski]

And I use Tap Magic.  I dint' think  I can go wrong with that stuff. 

[nkalanaga]

"Forward a quarter turn, back a quarter turn."

Wouldn't you stay in the same place, just going back and forth?

They way I was taught was forward half a turn, back a quarter. That way the tap advances a quarter turn with each cycle.

[spr1955]

Got the taps yesterday and they are made in Korea. It took 4 business days to ship and USPS 3 days to deliver.
They look nice and hope the HHS is of quality.

That is a spiral pointed tap and should be used on through holes as it is designed to push the chips forward and out the hole. With soft metals the back and forth motion helps prevent binding of the soft chips.  Hole size (predrilled) is most important, usually 70-75% thread engagement is standard practice but with our applications you could drop that down to 60-65% and make it easier to tap. We don't need to torque stuff down so we don't risk pullout.

[wvgca]

it's just as the name says ... a forming tap pushes the metal into the thread shape, good for softer materials, but needs a little more power  ..
on the other hand a cutting tap will usually require a little larger pre drill size [ as it is removing some of the material, and a litttle less power..
it depend on what you intend to thread ... each has it's place

[mike_lawyer]

I have an issue - I drilled a hole in the plastic floor of a Kato Mikado tender for an MT 1050 coupler.  I used a walthers 00-90 drill and tap set.  When I twist the screw, it will go down into the plastic, but will not tighten the coupler to the bottom of the frame.  The screw will keep turning but will not drive downward.

I was thinking I should fill the hole and re-tap.  Anyone have any advice on "filler" material?  Also, should I use a different tap than the walthers 00-90 tap?

[Lemosteam]

Epoxy a 00-90 nut on the inside or drill and tap a small piece of sheet brass to use as a nut inside the shell.

[nkalanaga]

If there's room that's what I'd do - use a nut.

If not, the floor is probably styrene, so drill the hole to fit and glue a piece of Evergreen styrene rod in it. With a tight fit and some glue, it will be as solid as the original floor, and can be redrilled.

The Walthers tap should work fine.  Possibly the original hole was a little too large, and there wasn't enough thread to hold the screw.

[samusi01]

An alternative to the styrene tube would be brass tube… more difficult to work with but possibly longer lasting as well. Just picked up some recently for experimenting on 3d printed cars.

[Sokramiketes]

Since moving to the steel, Philips head, M1.2 screws, I haven't used a tap in some time.  So much easier to torque into place with the Phillips head, forms own threads in all but the hardest metals, and have a smaller countersunk head to fit in the MTL boxes without needing to countersink the engineering plastic more (like for a 00-90 brass screw)

I keep 4mm, 5mm, and 6mm lengths on hand now. 

I use the same 00-90 tap drill, which is slightly undersized and leaves good material. 

Tapping, and using the brass screws, also lead to stripped threads more often than not in plastic underframes. 

[mike_lawyer]

Since moving to the steel, Philips head, M1.2 screws, I haven't used a tap in some time.  So much easier to torque into place with the Phillips head, forms own threads in all but the hardest metals, and have a smaller countersunk head to fit in the MTL boxes without needing to countersink the engineering plastic more (like for a 00-90 brass screw)

I keep 4mm, 5mm, and 6mm lengths on hand now. 

I use the same 00-90 tap drill, which is slightly undersized and leaves good material. 

Tapping, and using the brass screws, also lead to stripped threads more often than not in plastic underframes.

That sounds awesome that you don't even need to tap for those screws.  I also like that they have Phillips heads, that would be much easier to screw into place.  Where do you purchase the M1.2 screws?

[Sokramiketes]

https://www.ebay.com/itm/174815070821

[Sokramiketes]

This listing is a little clearer and you can pick 100 or 500 pcs.

https://www.ebay.com/itm/183914679946

[Sokramiketes]

As far as the sizes.

M1.2x5mm is probably my most used.  1015 MTL box is a little higher, and this one goes through that and the floor without sticking up past the floor. 
M1.2x6mm second most used, really runs home when the top doesn't show.

M1.2x4mm  least used but very specific for the thinner 1023 style MTL box and also not poking through a flat car deck.  When an axle is going to interfere with a 1015 box, low ride height situation...

[Lemosteam]

@Sokramiketes What is the diameter of the flat head 0n the M1.2?  Can you measure and post here?  The info on eBay does not show this dimension.