I get about 8 holes tapped then it snaps. The tap I'm using is an OSG EXO tap, 3flute, spiral flute, TICN coated. I'm sure there has to be some better taps available that may help. Posts 72 Downloads 0 Uploads 0 breaking taps, rigid tapping 10-32 in SS-304/304L This is a bit outside my usual work, I am tapping 10-32 with 3/4' thread length. In this case the tap was a 70's vintage craftsman brand. My tap felt like it was going to snap as well but in my case I didn't have a lot to loose and twisted harder than I thought possible without breaking, but the same tap held up through 6 holes. Maybe someone knows of a high end tap that would work better? I know some taps have coatings that are supposed to make them last longer, but not sure if they will make this specific job any easier. I'm sure you used it while tapping as well. You mentioned using cutting oil when drilling. I think it's just the difficulty with the material that is giving you problems. I'm sure I would have broken a tap in deeper holes as tough as the going was. I had hand taps so I did the usual 1/4 to 1/2 turn and back-up. I'm glad they were through holes and only 1/4" deep. The taps always seems to be brittle where the break and the weld just breaks off a little more of the tap.My recent experience is limited in ss304 to tapping about a half dozen through holes in some 1/4" material. a bolt). a nut).A die is used to cut or form the male portion of the mating pair (e.g. I have never had much luck welding taps, though it works great for bolts and set screws. Taps and dies are tools used to create screw threads, which is called threading.Many are cutting tools others are forming tools.A tap is used to cut or form the female portion of the mating pair (e.g. On a larger tap, I imagine that you could drill down through the middle and use an EZ out. Form taps can be operated at higher speeds and feeds than conventional taps. More Efficient Production: longer tap life, less tap breakage, and faster tapping speeds combine to reduce cycle time and machine downtime. The form tap had enough friction that this never seemed to happen. Longer Tap Life: forming taps can last 3 to 20 times longer than cutting taps because they have no cutting edge to dull. Oh, and try the best smelling tapping fluid for hand tapping stainless - Johnson's Baby Oil. This is especially true if the tap broke on the way out (they usually do). For example a 1/4-20 thread would normally be drilled 13/64' or 7 - but a 4 drill will make the tapping job much easier without significant loss of performance - at least in larger threads. The biggest problem I have had drilling out cut taps is that the tap keeps turning in the hole. I always use a sulfur bearing thread cutting oil. Cut thread tapping isn't so bad, just keep an eye on the tap for even the slightest bit of damage will cause grief. I was able to use a cut tap to clean the remains of the form tap out of the threads. By definition, a forming tap is workhardening the material, and the nickel in stainless has a great affinity for welding itself to whatever it is rubbing on it. The end mill didn't quite make it to the end of the tap, but it got close enough that I could finish with a 2mm end mill that I had.ģ/32 is pretty close to the minor diameter for a 6-32, so I basically removed the entire core of the tap. 001 at a time running 500 RPM with the hole full of oil. I chucked up a 3/32 carbide end mill that was laying around. The irony being that I was hand tapping the last bit to avoid breaking a tap. I managed to break a tap off tapping the last bit by hand. I bought 3/8 Easy-to-machine SS (type 303) rod from McMaster-Carr. Supposedly the taps and dies are made out of carbon steel. 125, then went at it with a Balax TIN coated threadfloer. of 2 - Threading Stainless Steel Rod - posted in ATM, Optics and DIY Forum: Ouside of using a lathe, is there a way to thread SS rod I bought a cheap (made in China) tap and die set yesterday. That might be the worst combination of numbers in a machine shop. In materials like stainless steel or bronze the relief angle should be larger to allow free cutting and to allow more lubrication to reach the cutting and.
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