I tap a ton of tiny holes and I’ve found that I just don’t have the dexterity anymore to hold the tap perfectly straight and not nudge it sideways when turning them. I use a tapping block or tap stand to insure the tap is 100% straight and also to keep me from putting side force on the tap. Some parts I make might have 50 1.2mm tapped holes and at that point there is many hours of machining and hundreds of dollars of material on the line.
I had a problem with undersized tapped holes in 316 stainless. They were close enough to 8mm to convince us they actually supposed to be 8mm. The bolts that came out were very close to 8mm but just undersize. A new 8mm bolt would almost go in but not quite.(no they weren't imperial.) All this was submerged in a waterjet tank (now empty). We tried to chase the thread with a good quality tap but got absolutely nowhere not even a half a turn. I tried a few different taps no luck. This wasn't even a new hole, it already had threads in it. I couldn't believe how hard it was. I called MSC and asked for there recommendation for their best stainless tap. It was the most expensive tap they had. The difference was extraordinary. It tapped like butter. In fact I put away the long tap handle and use a battery drill for the rest of the holes. A few dozen holes went by without any problems in minutes where we had struggled for hours to avail previously. I have bought material specific tooling in the past with good results but never this dramatic a difference. The tap didn't seem much different at a glance. But wow what a difference. There are plenty of applications where an ordinary tap works fine and an expensive one probably makes no difference but then in special cases the right tool is essential. Its a brave man that taps hole that small in 316 nice job.
Thanks. I think the combination of M1.4 and 316 definitely required a much higher quality tap. Now that I've tapped 30 holes by hand with this tap, I feel confident I can do rigid tapping the next time around. That will be much easier.
I love what you are doing , your approach and your presentation style. I am also a software guy with an interest in this. Please keep them coming! And hello from Ireland.
Serendipity! Just went through this process yesterday although in tenzalloy rather than stainless. New, sharp taps are a must. I broke an old, blunt tap in a blind hole and it ruined my day. I must make a few of those little knurled handles.
Thanks Mark. Those knurled handles are really nice. I kept seeing them in Joe Pi's videos and thought this project was just the place where I needed them.
This is exactly what I would expect with a tiny thread. I know it is done and in steel no less and on production mass produced parts. Can you imagine a CNC doing this? Good job on the video and the making part.
I did a few jobs where I had to manually tap the parts and it was such a pain, never again. I thread mill all my stuff now, I can dial it in and use a thread gage to check fit. I find it to be way more reliable and you at least have the chance to save a part with a broken thread mill. If I were to have a job that had hundreds of holes, I may consider rigid tapping, but for small job shop stuff thread mill is the way to go in my opinion.
I had a deadline and was originally counting on my viewer tapping the holes since I thought he had the expertise. I was wrong, so ended up having to tap them myself. I did some more research and it Guhring makes a thread mill. I'll have to look into that for next time, as breaking one of those would not scrap the part. The other thing I may try is rigid tapping with the spiral point tap, as I already have the taps.
Agreed. In this case, I got them from MSC Direct because McMaster only had one option, which was a straight flute plug tap. Whereas MSC had both straight flute and spiral point options.
@@JohnSL I bought a few tiny thread mills (for 2-56 holes) the other day that I really want to try out as I hate cnc and hand taping small holes, especially in titanium of ss316. I think they make them even smaller too
Also remember drill size for stainless steel are not the same as for regular steel. To avoid braking tap choose drill size a little bit larger or look up the correct size in table for stainless tapping
Oh, I learned that the hard way. I initially drilled the pilot hole smaller, and then discovered I needed to use a larger hole for stainless after breaking a few taps.
I used my CNC mill to drill the holes. Now that I have experience with the spiral point taps, I plan to try rigid tapping the next time. That should be safer and faster than hand tapping.
This is my first time working stainless steel. The Tap Magic label included stainless steel. Can you provide more about the advantage of Moly-D or Anchor Lube over Tap Magic?
@@JohnSL Anchor Lube is more popular reputation than anything else. Moly-D has a ton of molybdenum disulfide, which maintains a lubricant film under extreme pressure. Stainless has such a bad reputation that I went straight to Moly-D the first time I tapped it and it's worked very well.
I didn't feel comfortable with rigid tapping with a straight flute tap, which is all I had at the time. Next time I will try rigid tapping with either a form or spiral flute tap.
How about a Thread Mill? You can control cut parameters very precisely and it would save a ton of manual tapping. Perhaps not cost effective for small quantities, but awesome and repeatable once dialed in. Either way great vid, good insights
Still quite tricky for holes of this size - an M1.4 thread mill will only have a ~1mm neck, so you still need to be very careful with it. Chip evacuation is a real problem in a hole of this size and a tool of that size just won't tolerate chip recutting. It should work reliably once you've got the parameters dialled in well, but the pucker factor while dialling in those parameters is pretty high, especially with the issue of work hardening in austenitic stainless.
I drilled these holes on the Haas with the belief that my viewer was going to tap the holes. That was incorrect, so I had to tap them after additional machining that meant I couldn't get them perfectly aligned in the jig again. In the future, I plan to rigid tap.
Thats a spiral point tap , possibly better suited for through holes spiral flute would lend itself better to a bling hole ? tho its working well enough
Better is better. Something cheap will be purchased many more times than a product of quality making the quality a better value than the inferior product. Alas price does not always bring quality. A guide would be a great tool to use on small taps to make shure of your alignment. Nobody likes chaotic neutral in the workshop.
I thought about making a tapping guide. But, well, I didn't. No good reason for not doing it. But with the new tap, I could feel quite easily how things were going and was careful to not force things.
