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I had to drill out a marine bronze part to accommodate a 1" NPT fitting. The part originally came with a 1" NPT male threaded outlet, but I needed to convert it to female. But my biggest drill was 1" and I had no 1" NPT tap. So I found a tap and drill set on Amazon for $40, which was advertised as "Industrial Grade" and sold by "Drill America," which I presumed meant it was Made in China. The drill was advertised as "HSS high carbon steel."The drill and tap arrived. I cut off the male outlet and started drilling. Mind you, I was only removing ~1/8" of material around the circumference of the original opening. The bit chattered initially and never really behaved like a properly sharp and hardened tool. It did drill out the bronze, albeit slowly and with very fine dust-like chips. I tapped the hole and the new part fits fine. The tap performed perfectly. The drill is obviously not hardened sufficiently. It might have been fine for hardwoods, plastic, or aluminum, but that's not how it's sold.The cost of the set was less than a drive to the local machine shop + labor, and it's entirely possible I'll never need this again. But this doesn't strike me as "industrial grade." The question is, should I return the item because the drill essentially failed during its first use? Thoughts?Cheers,Q
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Reply:It's disappointing to say the least, but for the hassle of trying to return it, I'd be tempted to keep the tap and just buy a better 1" bit from a reputable supplier...The harder you fall, the higher you bounce...250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:See other thread about smoking bits. Just re-sharpen that with a drill gauge and you should be fine.www.tjsperformance.comDynasty 300 DXHTP 240HTP Microcut 380Hyperthem 85JD2 Hyd Bender and HF Hyd Ring Roller all in one =(Frankenbender)Bpt. Mill/DRO4' x 8' CNC Plasma TableInstagram: tjsperformanceYT: TJS Welding and Fabrication
Reply:In both your first and fourth pictures, the drill bit looks like it had recently been removed from a fire and is still showing a rough oxide coating or scale all over. That can't be from use, can it? Any pictures from before it was used? I would have considered the description, "HSS high carbon steel" to be somewhat troublesome in that HSS generally means one of a series of normal alloys like M2, while High Carbon is used for plain high carbon steel; the two are not the same. Were there any signs of inclusions in the casting after drilling or tapping? I wouldn't expect any in a US made pump, but depending on where that one came from and who poured it with what alloy or source of metal, anything is possible. However, if the finished threads all looked clean and perfect, I'd bet the bit was defective and I'd at least provide negative feedback. WRT returns, I ordered some boots from Amazon last year and had to try four times before the size I'd ordered was actually delivered. Apparently something in the computer system was showing different data to me and to their supplier; I'd documented my page view with screenshots so could prove it, and was on the phone for probably a few hours total for all the calls. I'm persistent; enough said.... The first return was somewhat of a hassle but the other three went well, as they had a Prime truck driver come within a day or so. I've never paid for Prime..Last edited by Oldiron2; 4 Weeks Ago at 12:09 PM.Reason: Removed a confusing comma
Reply:$40 is very cheap for that set, I would not have expected much. Fortunately, you got thru it and the tap worked. I would sharpen the drill and just park the set for a future just in case.Ernie F.
Reply:
Originally Posted by whtbaron
It's disappointing to say the least, but for the hassle of trying to return it, I'd be tempted to keep the tap and just buy a better 1" bit from a reputable supplier...
Reply:
Originally Posted by TJS
See other thread about smoking bits. Just re-sharpen that with a drill gauge and you should be fine.
Reply:
Originally Posted by Oldiron2
In both your first and fourth pictures, the drill bit looks like it had recently been removed from a fire and is still showing a rough oxide coating or scale all over. That can't be from use, can it? Any pictures from before it was used? I would have considered the description, "HSS high carbon steel" to be somewhat troublesome in that HSS generally means one of a series of normal alloys like M2, while High Carbon is used for plain high carbon steel; the two are not the same. Were there any signs of inclusions in the casting after drilling or tapping? I wouldn't expect any in a US made pump, but depending on where that one came from and who poured it with what alloy or source of metal, anything is possible. However, if the finished threads all looked clean and perfect, I'd bet the bit was defective and I'd at least provide negative feedback.
Reply:
Originally Posted by metalman21
$40 is very cheap for that set, I would not have expected much. Fortunately, you got thru it and the tap worked. I would sharpen the drill and just park the set for a future just in case.
Reply:If you went from the original size of 59/64 for 3/4" NPT to 1-5/32 for 1" NPT then only the very last parts of the flutes were trying to cut like you said. It is common for the bit to chatter when using a drill bit to slightly widen the hole. That chatter will seriously reduce the life of the bit. You might have been better off using a step bit that went to 1-1/8" if it would fit down into the holeMillermatic 252 MIGMiller Dynasty 200DX TIGMiller Spectrum 625 PlasmaAltas 12x36 Metal LatheBridgeport Milling Machinewww.psacustomcreations.com
Reply:i'm sorry but i don't have any sympathy for you buying a $40 "industrial set " and then being disappointed. all the signs of poor quality were there (and acknowledged by you.)sure amazon has a great return policy but you wasted time and effort.:
Reply:I can't tell from your pictures but that drill looks like what we would call a "carbon" drill. I still should drill bronze. Carbon drills often do not have the relief behind the front edge of the flutes that you see on high speed drills. I would expect a high speed drill of that size to be marked HSS. How many rpm were you driving the drill bit? It would need to turn very slow if it is a carbon bit. You can also tell by doing a spark test. The difference between the two is quite pronounced. Test a known HSS bit to see what it should look like.This may be the other thread that was referenced:https://weldingweb.com/vbb/threads/7...steel-flat-bar---Meltedmetal
Reply:This the bit/tap set?
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Reply:
Originally Posted by q240z
I only noticed the rust haze in the picture with a flash. IRL, the bit just looked like it had a black oxide coating. I've got some old-school drill bits that appear the same, but the steel is hard and they really hold an edge, even drilling stainless. This drill bit immediately lost its edge on this late-1960s American-made marine bronze part.
Reply:
Originally Posted by Lis2323
i'm sorry but i don't have any sympathy for you buying a $40 "industrial set " and then being disappointed. all the signs of poor quality were there (and acknowledged by you.)sure amazon has a great return policy but you wasted time and effort.
Reply:
Originally Posted by Oscar
This the bit/tap set?
Reply:
Originally Posted by Oscar
This the bit/tap set?
Reply:
Originally Posted by Oldiron2
Can someone explain the last sentence about running the bit Counterclockwise?
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Originally Posted by q240z
Not sure what you mean.As I said, the set did the one job and I saved time and money over taking it to a machine shop. Why do you think I wasted time or effort, beyond a few seconds drilling? That part of the operation literally took less than a minute.What were the "signs of poor quality" I acknowledged? ?
Reply:
Originally Posted by Lis2323
a $40 tap and drill made in china and described as "industrial grade" would make me leery when the amazon price for the equivalent made in USA tap alone is $80 cdn.
Reply: Originally Posted by Oldiron2 Can someone explain the last sentence about running the bit Counterclockwise?
Reply:
Originally Posted by Oldiron2
You missed my point. If a standard right-hand drill turns Clockwise, which way do the chips (that are following the flutes) go? If the bit is then turned "backwards" [counterclockwise], what happens to the chip?The tap in the set has straight threads, so their explanation isn't about it, either.
Reply:
Originally Posted by Oldiron2
You missed my point. If a standard right-hand drill turns Clockwise, which way do the chips (that are following the flutes) go? If the bit is then turned "backwards" [counterclockwise], what happens to the chip?.
Reply:
Originally Posted by Meltedmetal
If you are laying on the drill press table looking up at the drill, it is turning counter-clockwise.
Reply:
Originally Posted by Meltedmetal
If you are laying on the drill press table looking up at the drill, it is turning counter-clockwise.
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发表于 2022-9-16 15:52:17