Thanks Historian, I'll give that model a go. I've got so many dull bits I could probably spend a weekend getting them all back in working order.Historian wrote:cdakers wrote:What model did you purchase? I've been wanting/needing one, but have heard mixed reviews on the some of the lower end models.Historian wrote:If you don't have a drill doctor, buy one.
"Drill Doctor® Model 750X Bit Sharpener, 3/32" to ¾""
This model covers full range of drills. I also purchased a spare diamond wheel as
back up ... always have a back up.
Just used it again yesterday prior to drill in SS + Castroil Moly.
'Like cutting butter'
Best
Drilling Misshap
Re: Drilling Misshap
Re: Drilling Misshap
I sharpen mine by hand on the bench grinder too, although I don't even have one of those guides. I'm good down to ~3/16", smaller than that gets tricky for me to sharpen by hand.T-Rex wrote:This is my Drill Dr
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Re: Drilling Misshap
For the Lil guys, I put them in a small vise. It has a V notch that runs horizontal, down the center of the jaws. Lock the bit with a cutting edge about level. Place the point gauge on the bench, under the bit, and align by eye. Then, use a myriad of stone and ceramic blocks to sharpen the bit, whilst keeping them lined up with the gauge. Not too bad cause the little ones usually need but a few passes.yondering wrote: I'm good down to ~3/16", smaller than that gets tricky for me to sharpen by hand.
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Re: Drilling Misshap
Yes you need to use a center drill, slowly, and start drilling with the center drill down to the bigger angle. That will give your bit a good starting point and if the center drill goes through that alleviate some of the pressure on the drill point. Which will reduce some of the heat that builds up.
Re: Drilling Misshap
I don't work with a lot of hard materials, but I have drilled holes in steel targets before (AR500).
Carbide, carbide, carbide. Something hard enough to actually cut the material without being damaged.
I drilled several holes with a center-cutting carbide end-mill, it worked just fine (in a mill). In a drill press I expect it would want to wander, lots of radial load. I'm sure someone makes carbide drill bits, though.
Carbide, carbide, carbide. Something hard enough to actually cut the material without being damaged.
I drilled several holes with a center-cutting carbide end-mill, it worked just fine (in a mill). In a drill press I expect it would want to wander, lots of radial load. I'm sure someone makes carbide drill bits, though.
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Re: Drilling Misshap
We couldn't save either of the baffles due to the holes already put in them. We put them on a bench sander and we got one to .42 and another to .47.
Should I still consider using them?
I've already cut a spacer to replace them at the end off my can which measures 1.41 inches before the exit end cap.
Should I still consider using them?
I've already cut a spacer to replace them at the end off my can which measures 1.41 inches before the exit end cap.
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Re: Drilling Misshap
I don't see why you couldn't drill the baffles? Even if the metal was work hardened, 17-4 reaches a max Rc of >50. Carbide, even uncoated, is very capable of penetrating this. I thought there was mill access? If so, did you try trochoidal milling? That would definitely chewed threw even the hardest tool steel.
Anyway, onto your question. 2 baffles, even oversized, are better than none.
Anyway, onto your question. 2 baffles, even oversized, are better than none.
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Re: Drilling Misshap
The holes already in the baffles prevented the lathe from staying center. I'll use these as blast baffles. Thanks for answering my question.T-Rex wrote:I don't see why you couldn't drill the baffles? Even if the metal was work hardened, 17-4 reaches a max Rc of >50. Carbide, even uncoated, is very capable of penetrating this. I thought there was mill access? If so, did you try trochoidal milling? That would definitely chewed threw even the hardest tool steel.
Anyway, onto your question. 2 baffles, even oversized, are better than none.
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Re: Drilling Misshap
For anyone who happens to find themselves in a similar situation:
Forego worrying about center, for the start.
Indicate the baffle from the OD
Using a facing cutter, move away from center, plunge into the work and move towards center (light cuts are fine)
Do this until there is a flat spot
Center drill, drill, and ream if need be
If you've managed to make a terrible hole w/ the center drill or a pilot drill, do the following:
Indicate the work as above
Mount and center a small end mill (.125") in a tool holder, w/ a cutting edge level
Move the end mill into the work and try to just catch the hole
Take light cuts, boring towards the chuck, and you'll eventually get a nice round hole
Forego worrying about center, for the start.
Indicate the baffle from the OD
Using a facing cutter, move away from center, plunge into the work and move towards center (light cuts are fine)
Do this until there is a flat spot
Center drill, drill, and ream if need be
If you've managed to make a terrible hole w/ the center drill or a pilot drill, do the following:
Indicate the work as above
Mount and center a small end mill (.125") in a tool holder, w/ a cutting edge level
Move the end mill into the work and try to just catch the hole
Take light cuts, boring towards the chuck, and you'll eventually get a nice round hole
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Re: Drilling Misshap
A face grooving lathe tool would've worked great here. Or just a boring bar plunged in on an angle.
Id destroy these two and start over.
Id destroy these two and start over.
300 blackout form 1: http://www.silencertalk.com/forum/viewtopic.php?f=10&t=137293
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Re: Drilling Misshap
Thanks for this information!
Drills come in many different sizes and qualities with chinese drills leading the pack of cheap disposable drills that dont hold an edge very long, so is true for carbide and cobalt drills, you get what you pay for..usually if you go to JandLindustrial.com theylists all their tools as either import or domestic. Machinists know the difference between import and domestic tooling` Import tooling wears out too fast but is a great substitute when setting up a production job where you may break a tool or 2.
All the best: https://mechanicguides.com/best-cobalt-drill-bit-sets/
Drills come in many different sizes and qualities with chinese drills leading the pack of cheap disposable drills that dont hold an edge very long, so is true for carbide and cobalt drills, you get what you pay for..usually if you go to JandLindustrial.com theylists all their tools as either import or domestic. Machinists know the difference between import and domestic tooling` Import tooling wears out too fast but is a great substitute when setting up a production job where you may break a tool or 2.
All the best: https://mechanicguides.com/best-cobalt-drill-bit-sets/
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Re: Drilling Misshap
Ok where to begin, lots of wrong info here on working stainless
Get some rapid tap cutting fluid, the key to drilling stainless , low rpms, correct drill pressure and the most important thing, a sharp bit. You dont need carbide, you dont need cobalt, it just needs to be sharp. Keep the pilot bit as small possible. Your final size you want to drill out as must material as you can. 300 series stainless steel will not harden. Make sure you are producing chips , if the but is dull or your barely give feed pressure , that is just friction which overheats the bit and material
Get some rapid tap cutting fluid, the key to drilling stainless , low rpms, correct drill pressure and the most important thing, a sharp bit. You dont need carbide, you dont need cobalt, it just needs to be sharp. Keep the pilot bit as small possible. Your final size you want to drill out as must material as you can. 300 series stainless steel will not harden. Make sure you are producing chips , if the but is dull or your barely give feed pressure , that is just friction which overheats the bit and material
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Re: Drilling Misshap
Most of which is in your (necro) post.Weldingbiker wrote:Ok where to begin, lots of wrong info here on working stainless
Gear oil with sulfur is best for stainless (free machining grades are impregnated with sulfur to achieve that property), "low RPMs" is too ambiguous (match part material, cutter size, cutter profile, cutter material according to S&F), and austenitic grades absolutely do work harden-quite easily in fact.Get some rapid tap cutting fluid, the key to drilling stainless , low rpms, correct drill pressure and the most important thing, a sharp bit. You dont need carbide, you dont need cobalt, it just needs to be sharp. Keep the pilot bit as small possible. Your final size you want to drill out as must material as you can. 300 series stainless steel will not harden. Make sure you are producing chips , if the but is dull or your barely give feed pressure , that is just friction which overheats the bit and material
If a part is already work hardened, HSS is easily smoked trying to punch it. Ergo the suggestion of carbide, which will easily chew through even the hardest steels with a lot more latitude for S&F variation.
Finally, a tip: Don't sign up on a board just to condescendingly argue with it's members in your very first post. Doesn't make people want to listen to you, just paints you as an A-hole.
FFL07/02SOT Gunsmith & Machinist
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Re: Drilling Misshap
Spot on.ECCO Machine wrote:...
300 series stainless work hardens if you look at it wrong, even 303.
A sharp bit should always be used, never mentioned.
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Re: Drilling Misshap
It does not work harden , doesn't have the correct properties
400 series is hardebable and that's why its useful for a knife, again the nickle in 300 is soft and stabalizes the metal in a non magnetic non harden state
Not arguing dude,trying to educate
The reason you smoke a bit, its dull, no lube and most important too high rpms
I've drill so many holes with just a black oxide and stainless
400 series is hardebable and that's why its useful for a knife, again the nickle in 300 is soft and stabalizes the metal in a non magnetic non harden state
Not arguing dude,trying to educate
The reason you smoke a bit, its dull, no lube and most important too high rpms
I've drill so many holes with just a black oxide and stainless
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Re: Drilling Misshap
Austenitic stainless steel is a specific type of stainless steel alloy. Stainless steels may be classified by their crystalline structure into four main types: austenitic, ferritic, martensitic and duplex.[1] These stainless steels possess austenite as their primary crystalline structure (face centered cubic). This austenite crystalline structure is achieved by sufficient additions of the austenite stabilizing elements nickel, manganese and nitrogen. Due to their crystalline structure austenitic steels are not hardenable by heat treatment and are essentially non-magnetic.[2]
There are two subgroups of austenitic stainless steel. 300 series stainless steels achieve their austenitic structure primarily by a nickel addition while 200 series stainless steels substitute manganese and nitrogen for nickel, though there is still a small nickel content.
300 series stainless steels are the larger subgroup. The most common austenitic stainless steel and most common of all stainless steel is Type 304, also known as 18/8 or A2. Type 304 is extensively used in such items as, cookware, cutlery, and kitchen equipment. Type 316 is the next most common austenitic stainless steel. Some 300 series, such as Type 316, also contain some molybdenum to promote resistance to acids and increase resistance to localized attack (e.g. pitting and crevice corrosion). The higher nitrogen addition in 200 series gives them higher mechanical strength than 300 series.[3]
Other notable austenitic stainless steels are Type 309 and 310,[4] which are utilized in high temperature applications greater than 800°C.
Alloy 20 (Carpenter 20) is an austenitic stainless steel possessing excellent resistance to hot sulfuric acid and many other aggressive environments which would readily attack type 316 stainless. This alloy exhibits superior resistance to stress-corrosion cracking in boiling 20–40% sulfuric acid. Alloy 20 has excellent mechanical properties and the presence of niobium in the alloy minimizes the precipitation of carbides during welding.
Austenitic stainless steel can be tested by nondestructive testing using the dye penetrant inspection method but not the magnetic particle inspection method. Eddy-current testing may also be used.
See also
References
External links
There are two subgroups of austenitic stainless steel. 300 series stainless steels achieve their austenitic structure primarily by a nickel addition while 200 series stainless steels substitute manganese and nitrogen for nickel, though there is still a small nickel content.
300 series stainless steels are the larger subgroup. The most common austenitic stainless steel and most common of all stainless steel is Type 304, also known as 18/8 or A2. Type 304 is extensively used in such items as, cookware, cutlery, and kitchen equipment. Type 316 is the next most common austenitic stainless steel. Some 300 series, such as Type 316, also contain some molybdenum to promote resistance to acids and increase resistance to localized attack (e.g. pitting and crevice corrosion). The higher nitrogen addition in 200 series gives them higher mechanical strength than 300 series.[3]
Other notable austenitic stainless steels are Type 309 and 310,[4] which are utilized in high temperature applications greater than 800°C.
Alloy 20 (Carpenter 20) is an austenitic stainless steel possessing excellent resistance to hot sulfuric acid and many other aggressive environments which would readily attack type 316 stainless. This alloy exhibits superior resistance to stress-corrosion cracking in boiling 20–40% sulfuric acid. Alloy 20 has excellent mechanical properties and the presence of niobium in the alloy minimizes the precipitation of carbides during welding.
Austenitic stainless steel can be tested by nondestructive testing using the dye penetrant inspection method but not the magnetic particle inspection method. Eddy-current testing may also be used.
See also
References
External links
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Re: Drilling Misshap
You don't seem to understand what work hardening is, how it happens.Weldingbiker wrote:It does not work harden , doesn't have the correct properties
https://www.bssa.org.uk/topics.php?article=122
You're not educating anyone here, just propagating misinformation. C&P of Wikipedia articles doesn't help your case, either. While a great starting point when one has interest in a topic, a comprehensive, accurate resource it is not due to the ability of anyone with internet access to edit an article.
FFL07/02SOT Gunsmith & Machinist
Re: Drilling Misshap
The stainless steel information centerWeldingbiker wrote:[300 series stainless] does not work harden , doesn't have the correct properties
The 300 series stainless steel can be "hardened" BUT only by "work hardening."
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Re: Drilling Misshap
Lots of metal can "work harden" but in the true sense that tiny amount is not harden
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Re: Drilling Misshap
Now you're just making a fool of yourself. When you're dead wrong about something, it's better to admit it than double down or try to use semantics to wiggle out of the tight spot you put yourself in.Weldingbiker wrote:Lots of metal can "work harden" but in the true sense that tiny amount is not harden
I don't even understand why you brought up playing with 300 series when the thread is about poking holes in 17-4, a precipitation hardening martensitic alloy that behaves nothing like 300 or 400 series.
If you want to discuss building suppressors, we're all game.
If you want to discuss metallurgy and machining, gonna have to forget what you "know" and start over.
If you're going to continue on your present path, there's nothing here for you.
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Re: Drilling Misshap
Wait a minute. You just said:Weldingbiker wrote:Lots of metal can "work harden" but in the true sense that tiny amount is not harden
Well, which is it?Weldingbiker wrote:It does not work harden , doesn't have the correct properties
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Re: Drilling Misshap
I explained it quite clearly. The tiny, that means small , amount is not considered hardened
Re: Drilling Misshap
I have had almost every form of SS work-harden. Occasionally to the point where high quality tools self destructed in further attempts to machine it, and cutting tools dulled or broke. Is there some suggestion that the "hardening" seen in friction-induced heating is metallurgically different than the intentional hardening of standard carbon steels? I can't believe that anyone working with stainless finds the amount of "hardening" to be trivial, it has brought many a machinist, pro and amateur, to head-banging fits of anger when nearly completed work suddenly starts to hate your guts!
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Re: Drilling Misshap
The only thing you, clearly, explained is your lack of knowledge in this field.
There are many of use here who do more with metals than simply make silencers.
Personally, I design burners for, among other things, Oil, NG, and Coal fuel industrial boilers and kilns. These are usually for energy producers or the world's largest mining operations. Our parts are produced in everything from Aluminum to Ceramic composites. Knowing the metals and materials is a huge part of our job.
While the project fizzled away, several years ago we messed with surface hardening 300 series SS, via the Nitriding process. IIRC, the 2 types we tested were 302 and 321. The latter gave stellar performance. All aspects of the base metal were improved, from wear resistance to weldability. Albeit to a minimal depth, the part was absolutely hardened.
And, like so many have also reported, 300 series SS can very much work harden. It takes only a small amount of time with machine tools to learn this.
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Re: Drilling Misshap
Yeah, I only face drilling stainless a few times per year in my work, but I've learned the hard way how easily 304 and similar cheap commercial grade stainless steels can work harden with the wrong speed, even when well oiled and using brand new bits. Bringing the surface up to something close to case hardened when a complex part is almost complete is extremely frustrating. Especially on a Sunday when there's nowhere open to buy a carbide bit. Weldingbiker seems to be determinedly stuck in a defensive position, when he'd be better off doing a bit of reading on the subject and learning from pros like ECCO.