Where to buy mid-grade Bottom Taps

davidpbest said:
With 304 and 316, technique is just as important as the tap quality. Both materials will work harden quickly if the tap is "pecked" (start, reverse, start again, etc.) which is the most typical reason for tap breakage. So I only machine tap those materials which is why I set up my mill with momentary forward/reverse buttons specifically for tapping. as well as auto-reversing. And I plunge to full depth before reversing. Lube is your friend here. And I spot SS with 140° spotting drill and pilot drill exclusively with cobalt 135° points.

At M6 and larger, the risk of breaking a tap in 304 or 316 is much less than on smaller sizes. So at M6 and above, I generally use high grade HSS Morse taps that are either steam oxide or TiN coated - these are available from Maritool. Anything smaller than M6 I use cobalt steam oxidized taps available through McMaster.

M4 and M3 deep bottom tapping in 304 is the most challenging since the tap needs to be spiral flute to extract the chips, and I typically pilot drill 0.1mm oversize in those situations if possible. On M4 or smaller, if at all possible, I will drill through the material and use spiral point tap even it it takes longer and requires longer drilling time, just so I can avoid using the more fragile spiral flute taps.

I'm sure there are other formulas and tap brands that work for others, but this is what I have come to after lots of broken taps and burnt-up drills.
Click to expand...
David, what is Steam Oxide? is that just a plain back oxide?
 
Thanks guys I appreciate all the links and insight on the taps.
 
David, are you using H 3 taps for most of this? Thank you for your other response.
 
you can get some very good deals on Amazon if you take your time. Most of the spiral flute/ point taps I've bought in the last few years cost between $5 and 8.
 
Aukai said:
David, are you using H 3 taps for most of this? Thank you for your other response.
Click to expand...
Yes, 90 percent of my taps are H3. I do have some higher tolerance versions, but only in larger sizes for a very specific application. Imagine having 4 hours in a part and you break an Amazon non-name or eBay OSG counterfeit M4 spiral flute tap in a deep hole - that’s when you kick yourself for cheaping out. Been there, done that. I should add that I have and can recommend OSG and YG-1 taps for general use, but prefer the previously mentioned taps for SS.
 
Thanks David, Right now what I need the taps for should not be to difficult. I need to install the DRO on both the lathe and mill and the power feed stops on the mill. Currently only have a couple of select metric taps purchased at the local ACE hardware store. I figured at this point I should start buying higher quality stuff.

Tim
 
The taps I've bought off Amazon have all been brand name: Morse, Union Butterfield, GTD, Widia and the like. Just have to be patient.
 
mattthemuppet2 said:
The taps I've bought off Amazon have all been brand name: Morse, Union Butterfield, GTD, Widia and the like. Just have to be patient.
Click to expand...
Amazon is rife with counterfeit products - particularly in backwater territories like taps. Not everything from Amazon is fake, but why would you not buy from a reputable dealer instead, where you know what you're getting is the "real deal"? Boggles the mind. Amazon knows zilch about taps. Carbide Depot, or McMaster, or MSC, or even KBC are better sources. They may not offer free Prime shipping, but IMO, it's worth the difference to deal with a distributor in the machining segment - or deal direct with the manufacturer. Just my 2 sense. I'm sure others have found pure gold at the bottom of the eBay pond - including me at times. :)
 
Last edited:
 
You must log in or register to reply here.
Back
Top