Still working on this project. I have ordered a new rod of 1/2" 303 stainless ans the only American made cutting die I could find (Irwin). Everything I have read says to use a good cutting oil for stainless and many recommend Rigid Extreme Performance-but i can only find that in gallons and I only need to cut two 2" long thread portions. Any suggestions for a less expensive but successful subs***ute will be greatly appreciated.
the only metal i can think of requiring special cutting fluid is aluminum. some cutting fluids say for all metals except aluminum. a machinists hand book would be the correct source for this information.
you can go to one of the big box stores and buy a small bottls of dark cutting oil , use it all the time cutting, threading ( ****on dies) or tapping on SS both by hand and machine cheap down and dirty . there are a lot of other's such as tap magic but that should do fine
RapidTap works well for ferrous metals (except cast iron), you can find that easily. Thread it slowly; about a 1/2 turn at a time after you get it started, backing the die off after each 'cut'. Hopefully this isn't a high-stress part. Stainless is only equal to about a grade 3 steel bolt, and cut threads are much weaker than rolled threads.
cheap ....5 bucks .......you can buy it today ...... use it for drilling, tapping ,cutting, whatever.........get er done
Best thing I've found [by accident] to cut threads in stainless is never-seize , yep , the stuff you use to keep stuff from seizing , grey paste, works great !! dave
The problem with stainless steel is that it work hardens quickly when heated during machining. 303 doesn't harden as quickly as 304. Any coolant that will remove the heat and lubricate will work fine. I use tap matic or the moly tapping fluid. Put a lead in on the end of the shaft so the die will start easily.
agree 100% wd-40 on alum,,, but WTF this poor guy asked for a inexpensive subs***ute, he's sounds like he is smart and has his wits about him...... he getting everthing but the kitchen sink thrown at him.... i bet ya this will end up being 10 pages long ...can we get anyone to chime in about using lard or bacon fat?
Yep , that's the right at***ude , go to a machine shop , god forbid anyone on here would have a good/ cheap solution .... dave
Thanks. Nothing like asking a question on the HAMB. Advice, recipes and digression. In addition to the answers given here, I also received advice for using Rapid Tap,brake fluid,Oatey dark Cutting oil, Crisco and Castrol Moly Dee. I don't want to screw up the project, but i also don't need a gallon-or even a pint of cutting oil. Hoping to find someone close with an open can. Maybe I'll try the Never-seize idea since I have that on hand.
Geez, you can get Rapidtap in a 4 oz bottle for under five bucks, even a pint should be only about ten.... If you cut, drill, or thread metal, you should have some. Most any decent hardware store should carry it.
OK. I will look-keep in mind it my search for a good quality die led me from the local hardware chain to Napa,Advanced Auto, A & A, Lowes, Federated Auto Parts, Tractor Supply,Sears and I finely ordered a USA made on from Grainger. FWIW, I belong to the Farm Bureau which not only gets me a very nice discount from Nationwide Insurance, but also a discount on almost everything from Grainger-and free shipping.
After everyone gets done telling their black magic solutions, the best you are going to find easy and cheap is pipe thread cutting oil. You need high lubricity more than "best cooling" because you are doing hand work. (on a lathe it would be different) If you have a choice lard oil is better than straight mineral oil. The suggestion to back up to break the chips is correct to a point, (you have to break them) but the less times you back up the longer your die will last. I would start going one full turn forward, then back 1/2 turn, then forward to the cut plus one full turn, then back 1/2 turn, repeat until done. If possible use an air hose to blow the chips out of the die, if they can't be blown out back the die all the way off the work and clean the die with a dental pick. (careful when using an air hose around threading chips, getting them in your eyes is a *****)
+1 on keeping dies [and taps] free of chips and being careful with the air hose. I keep old tooth brushes handy [stored right with the taps and dies] to clean larger dies and all taps. Ed
I ordered 4 oz of RapidTap from Grainger. Under $4.00 and shipping to arrive in 24 hours with my Farm Bureau discount.
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