2mm tap

Based on the recommendations for a forming tap I went to McMaster to see what they have. They have a 2mm bottoming-chamfer tap, and the recommended drill bit is 1.8mm. It seems like an oddball size but they do have them. I do like the fact that no chips are created by the forming process.

I already have two cutting taps (they arrived yesterday). I'll do a trial run on some scrap aluminum and see how it goes. I have a smaller tap wrench I use for tapping smaller holes so should be OK there.

Thanks for all the information!
 
You are overthinking this. The best info out of these comments is that you must keep the tap perpendicular to the hole and on center. The best way I found to do this is if you have a drill chuck with a straight shank (.500") you can put a 3/4 x 1/2 bushing in a collet and the shaft goes in the hole. Use the chuck to hold the tap and reduce your leverage potential. You can feel the cutting of the threads and back off to break the chip with no effort. I'm a machinist of 40 plus years and have tapped almost every material that can go into a Mars Rover... A-9 or tap magic is fine for aluminum... WD 40 works well too!
 
Take a look at Joe Pie's tap holders for small holes (even in steel). The spring loaded tapping guides have reversible ends so you can use either the pointed end with conventional tap holders or the cupped end directly on the back end of the tap. They can be held in the same drill chuck you use to drill the holes.

Make sure the hole is the right size for the material being tapped: 75% engagement for Aluminum, 600% for steel.
 
If you are using tap magic and doing it by hand you shouldn’t have any problems. I would use a new quality tap. No imports.
I agree 100%,
A good spiral flute tap has much less resistance.
 
This, or a thread forming tap. Advantage is stronger tap and stronger threads.

In either case, the key is keeping the tap vertical. A tap follower (spring loaded guide) may not work with a tap that small.
I find this to be incredibly useful, especially for small taps.

View attachment 457268
Never used a forming tap. You would think it would put up a fight.
 
I took a pic for you guys today to show you why the forming tap is stronger despite the fact that it puts up more fight. The cutting tap has about 30% less metal compared to the forming tap. These are both 2mm taps.
PXL_20230818_184449639.jpg
 
Take a look at Joe Pie's tap holders for small holes (even in steel). The spring loaded tapping guides have reversible ends so you can use either the pointed end with conventional tap holders or the cupped end directly on the back end of the tap. They can be held in the same drill chuck you use to drill the holes.

Make sure the hole is the right size for the material being tapped: 75% engagement for Aluminum, 600% for steel.
I've got a small pin vise I can use for holding the tap. It doesn't use a collet, instead it uses a simple-to-machine holder with a hole sized for the drill or tap. In fact, the whole thing would be pretty easy to make.

Like this:
T-D Holder1.JPG
T-D Holder2.JPG

I've had this set for years. Rarely used since it's specifically for small drills and taps. I'll drill a shallow hole on the opposite end for my spring loaded tapping guide. If I didn't already have this guy I probably would make a Joe Pie version. Or if doing a bunch of holes that require both a tapered and a bottom tap.

BTW you can see the price sticker on the box. I bought it at a local hobby store for $12.98.
 
I've got a small pin vise I can use for holding the tap. It doesn't use a collet, instead it uses a simple-to-machine holder with a hole sized for the drill or tap. In fact, the whole thing would be pretty easy to make.

Like this:
View attachment 457465
View attachment 457466

I've had this set for years. Rarely used since it's specifically for small drills and taps. I'll drill a shallow hole on the opposite end for my spring loaded tapping guide. If I didn't already have this guy I probably would make a Joe Pie version. Or if doing a bunch of holes that require both a tapered and a bottom tap.

BTW you can see the price sticker on the box. I bought it at a local hobby store for $12.98.
That's a interesting tool. I found this, they sell screws as small as 0000-160.

There is also a PDF catalog. I feel like the watchmaker in the old joke - "What did the watchmaker say when he saw a 1/4 - 20 tap for the first time? I didn't know they made 'em that big"! I'm looking at the 0000-160 screws and threaded rod they sell thinking - I didn't know they sell 'em that small. I know about the small thread series, but I never seen a supplier offer anything smaller than 0-80.

Many years ago, I used a 0-80 tap and die to make a low temperature differential Stirling engine from plans in James R. Senft's book. I used my smallest T wrench with the handle removed and my thumb and index finger on the knurl of the T wrench to tap the threads. I did it while seated and resting my arms on the bench. I got lucky and did not break the tap. I felt like an hour at the time, but actually it didn't take much longer than tapping a 4-40 thread. The act of tapping a 0-80 thread is the same as a larger tap, just be very, very gentle I kept telling myself. Very nerve racking the first time. Afterwards, I'm like "0-80 tap? No big deal."

Based on what I've seen of your posts, you will have zero problems tapping a 2mm thread. :) Thanks for sharing the J.I. Morris tool photos.
 
If the sizing convention for machine screws holds, a 0000 screw would have a diameter of .021" I find it hard to imagine tapping a thread it that small a hole! How about single pointing a 160 tpi screw?
 
Back
Top