Wrnchbndr
Wholenote
Posts: 353
Formerly Known As: WRNCHBNDR
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Post by Wrnchbndr on Apr 22, 2021 18:28:11 GMT -5
Need some guidance for an evil project. I’m making a B-Bender. The raw material is 5/16” steel rod ordered from McMasterCarr. I will need to drill and tap into this rod and I will also need to bend tight 90 degree angles with a 1/2” radius. In the end, I want to hot blue it. I’ll need to leave about 3”s straight so it’ll rotate in bronze sleeve bearings. The accuracy of the bends is not critical.
I have a drill press, a large vise, and map gas. Can this be done without oxyacetylene? What would be a good alloy?
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Post by Pinetree on Apr 22, 2021 20:28:19 GMT -5
304 or 316 is the shiny stuff.
It takes from 275°F to 315°F to Blue, so your MAPP gas should be good.
Personally, I'd wait for Geno to show up with all the info.
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Post by Peegoo 🏁 on Apr 23, 2021 1:17:26 GMT -5
You're cracking me up, Mike!
There's really no secret to this stuff; the forces the steel will take are not a problem for the size of the rod you're using.
Heat it to cherry red and quickly bend it to shape (over a round rod in the jaws of a vise). Once you have the shape you need, reheat the entire part and quickly quench it in used motor oil to blacken the steel. It may spit flames from the oil, so take necessary precautions, e.g., double up on the Trojans, wear goggles, and have your attorney on speed dial.
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Post by Pinetree on Apr 23, 2021 3:09:32 GMT -5
See?
I forgot about the used motor oil.
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Post by Peegoo 🏁 on Apr 23, 2021 9:19:07 GMT -5
Also: drill and thread the steel before you do the oil quench.
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Post by Leftee on Apr 23, 2021 9:36:48 GMT -5
You had me at, “spit flames from the oil.”
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Wrnchbndr
Wholenote
Posts: 353
Formerly Known As: WRNCHBNDR
|
Post by Wrnchbndr on Apr 23, 2021 11:03:24 GMT -5
...but whaaa... I’m just getting the hint of a clue when it comes to dealing with steel. I like using brass and have done a few super evil and successful things with brass and aluminum only having been successful because of dumb luck, a tolerant belt sander and good genes that make lacerations and burns heal quickly. I’d like to use brass rod but there are too many nay sayers on the interweb that are telling me that I can’t bend 5/16” brass rod with sharp radiusesses. You touched on what my main concern is. I need to be able to drill and tap this 5/16 steel rod. Happy to buy a couple of good drill bits. The steel needs to be soft enough for the drilling and tapping. Then I need the steel to harden up a bit when I quench it. It’s only from reading the description of the McMasterCarr narratives that I assume that these alloys are softer in their initial state when you receive them — geezer exposes his true ignorance of steel. What would be a good alloy? Does it matter if the used motor oil is from a Ford, a Dodge, or a Lexus with a transmission problem? How used does it need to be? I was gonna buy store bought blueing chemicals.
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Post by De ville on Apr 23, 2021 15:23:08 GMT -5
Stainless steel is incredibly hard to drill, and tapping it is harder than with regular carbon steel. Stainless steel hardens with heat, so you have to drill it at very low RPM's, and a lot of pressure on the bit + tapping oil.
It absolutely can be done, but you would need a drill press to do the drilling, forget drilling it with a cordless, it's not precise and difficult. Use high quality hardened metal drilling drill bits and tapping oil. One approach is to do the drilling in progressively larger holes until you get to the size you need, IE start with a 1/8th , and work up to a 3/16th for example. Keep making separate drill passes. If you run the bit in too far in 1 pass, the bit can jam in the metal. Make multiple passes, and keep adding oil.
The metal you go with depends on what you need from the metal. It could be you go with a softer alloy, and have your part chromed for finish appearance. Alternately the part could be powder coated. If it needs to be stainless, then know how to properly drill and tap stainless. You should be able to bend 5/16" stainless with not a ton of heat. Just get it red hot.
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Post by zoikzz on Apr 23, 2021 16:21:36 GMT -5
Threaded rod of any material is quite cheap. Experiment then decide. Yes, the S.S. will be tougher than plain carbon steel. Yes, tap before the heat treatment. If too tough and you start to break tap. Then increase the tap drill size to decrease the percent of thread depth. You can pull teeth with a 10-32 thread. If you want to send to me I can tap the ends because I have a lathe at work. The only way to go for tapping round stock.
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