I'm thinking about buying some Mittler Bros punch and flare dies. These use a draw bolt to punch and flare the hole. Obviously, you need to lubricate the dies for best operation. Drawing these in with a ratchet seems slow. Has anyone used a battery powered impact wrench to draw them down? How well does that work? Also, I have a Blackhawk porta power. Does anyone make a readily available and reasonably priced hydraulic actuator that accepts the 1/2" unc draw bolts that i could use with these? Any experience comparing hydraulic vs impact wrench? Which is best? Thanks!
I have SWAG punches and flare dies. https://www.swagoffroad.com/collections/swag-dimple-dies-knock-out-punch-set They fit the Harbor Freight conduit punch setup nicely. Hydraulic Punch Driver Kit, 14-Piece https://share.google/vYZnEgzfO84MLraD3 I run mine with an air over hydraulic pump, but they will work fine with the included hand pump. https://www.harborfreight.com/10000-psi-air-hydraulic-pressure-pump-58047.html Mittler Bros make stellar stuff, and my shop is loaded with it. Their through holes are different that what that hydraulic drawbar fits, but I am certain that they are top quality.
I have punched and flared 1/8" and 3/16" cold roll with this setup. It did bog down a bit on 3/16", but it did do it. It handles 18ga like it's not there.
I have some SWAG stuff, too. Their quality has always been good. Thanks. I really will only do up to 16 ga. And the Mittler stuff looks like it fits my need best.
I bought the full Woodward Fab set a few months ago, but have used them sparingly. They use the same drawbolt style as what you are considering, and I haven't use them with an impact nor a hydraulic driver, though I may try that in the future? Not sure, honestly. While using the drawbolt may seem slow, it allow both halves of the die to align properly as they are slowly being tightened-- not a bad thing. I'm not sure quickness is critical when using these, as the hydraulic driver's main appeal seems to be less physical effort required on the part of the operator. One thing I want to note is the shape/contour of the flare when finished. I specifically chose the Woodward Fab dies because the "mouth" of the flare is a smooth curve (when viewed in cross-section), while most (all?) others seemed to have a 45* angle/chamfer in the "mouth", something I didn't want. The factory flared holes on my Nash are of the smooth curve variety, so I want to stay consistent on that front.
As a guy who regularly used this type of punch during my career (electrician), I'll make a couple of observations. Don't use an impact driver if using the draw-through bolt as the risk of damaging the threads is pretty high. To reduce effort and wear, you need a thrust bearing on the bolt also, another reason for not using an impact driver. This makes a HUGE difference, especially in the larger sizes. For lubrication on the bolt threads, use grease, not oil. For the cutting edges, use a cutting fluid like Rapid-Tap or similar. Ideally, a hydraulic ram should be used, particularly if cutting thicker material. This will eliminate wear on the bolt threads. This also makes keeping the cutter centered much easier. One thing I am curious about; does the HF 10 ton pump have a lot of 'omph' ? The reason I ask is I have a full set of conduit punches up to 4" trade size, once you go above 2" the effort gets pretty high if using just the bolt. It doesn't help that my bigger punches are more than a bit worn, I doubt if I would even try on 1/8" material, I'd guess that 12 gauge is probably the upper limit now. Has anybody tried one of these with a cutter larger than 2.375"?
We have used them for years in NASCAR shops& will often use them in a hydraulic press. Also cordless impact with extra trust washers and plenty of pressure lube on threads and washers.
This is 1/8". Punched and flared with SWAG tools, driven by the HF hydraulic unit. Absolutely no issues.
So, you are using the ram from the knockout kit witth the air driven pump, if I understand correctly. Did you have to make a stud for the knockout ram or are you using the stud that came with the kit?
Yes, I use the HF ram with the air driven pump, but it works just fine with the hand pump that is included in the kit. The air driven pump is not necessary. It is a luxury, or in my a case, an ***istive device. I am partially disabled, it helps me a lot. My shop is full of air and hydraulic cylinder driven tools, and foot pedals to actuate them. You use the studs that come with it. There are two sizes (on the die end). The smaller punched and dies take a smaller diameter stud, for obvious reasons. The SWAG tools are designed to work with this unit. I did get some oversized heavy-duty nuts for use with the flaring dies, as the are not threaded. Those were a few dollars each at McMaster-Carr.
The only things that I added to this setup were the aforementioned heavy duty nuts, and one hydraulic hose adapter. The outlet on the air over hydraulic pump was a different size than the hose. That also was just a few dollars from McMaster-Carr.
You mentioned the HF kit, I bought the knockout set just for the pump, the set was 10 bucks more than the pump by itself. I need to see if it will work for my set of Greenlees.
I’ve got a few of the Mitler flare dies with the draw bolt. Not the punch and flare type. Only use them on sheetmetal. Battery impact works great. I put anti seize on the bolt and washer. Washers get worn out on occasion, maybe one bolt since I’ve had them. Threads in dies still look like new.
Instead of an impact, perhaps a great big old drill with low speed and a lot of torque could be used?
I use A impact just do small bursts and be careful not to ram the bolt into the washer and die or you will pull the threads.
I have an inexpensive UK made (by retired guy in a shed I think) set of flare dies which don't have the cutting edge. I drill the required hole with a stepdrill or annular cutter ( annular works great on stainless) and press the flare in an hydraulic press. Admittedly the panel size is restricted by the frame of the press so I'm looking into the hydraulic knockout punch route. The 2 step operation is clearly slower than the combined punch and flare but I suspect the equipment is rather cheaper, and easier to make if that's the way you roll. Chris
I have done many many punch and flared holes with MB dies. From 1" to 2 1/2". On the small ones with the real small draw bolts I will use a couple wrenches but all the rest I use a battery powered impact. Just like said above I use anti seize on the threads and keep the cutting edges lubed up with oil. Most of mine have been in 18 and 20 ga.
I use the cheap Harbor Freight porta power looking setup with flare dies I machined. I haven't used it enough to wear it out but for occasional use it has been satisfactory.
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