non-knife heat treat, semi o/t?

S

SR_matt

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Jan 4, 2007
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im not sure if this is ok for this sub forum or what but i think this would be the best place for it since many people here work with metals ingeneral not jsut for knives, i appologize if i am wrong.

should steel pieces that are going to be put under minial stress be heat treated. the piece im trying to make is non knife related at all but i would assume you could say the stress it will given is about the same amout as anyother part of a knife than the blade (but no blows to it). the best way i can explain the piece im making is that its a cylinder that fits in a tube, has a screw that goes into it that holds it in. in the back end theres a screw that screws in and the screw ends up pushing onto a washer that pushes on a spring (noting really strong). the threading is going to be semi coarse threads so im not to worried about cross threading. i think the steel i can get in the rod stock is in w1 or a2 (both come annealed).

if i need to get it HT what RC should i get it tempered down to?

thanks, again if this is not the right place im sorry
-matt
 
I don't think the part you need would have to be hardened if it's not under much pressure. It might not even need to be steel. It does make sense to use coarse threads.
 
i had thought about using Al but the industry standard has been steel so i dont think im gona risk it. it doesnt really have a danger risk if it breaks (might damage the piece its in slightly) but since its not for my personal use i decided not to risk it)


-matt
 
o ya i definatly forgot that there is a piece that is made from stainless that might be hitting one side of it, it only has 85psi ish forcing it back so im not sure if it could mushroom out the steel (this is for a paintball marker so it will get cycled 1000s of times).

-matt
 
naw i havent even had a chance to order the material yet.

this is so saddening, ive been so busy i havent had time to work on any knives or anythign else for that matter. pshh i just got my computer back after like 2 weeks (apple couldnt get my repair done fast enough so they just gave me a new, better, sexier computer ~happy dance~)

ill try to put up some pics of the part once i can get around to fab'ing it

-matt
 
If it's annealed, you may want to normalize it and get it back to "regular" hardness. Holding the steel at 1500 for a bit and then letting it air cool should transform the pearlite into austentite, which will hold up to any sort of force better than pearlite, while remaining workable.
 
Heat-treating a section of steel might change it's shape.
I would not want you to get everything fitting snug, only to HT and then find things are slightly different after...
 
the only part that i would be to worried about the tolerances is the threading (one is normaly done is a 10-32 thread and the other odesnt matter much but is a coarser thread done in a larger diamater ) as long as it fits in the tube and doesnt have a huge amount of play (huge being like 1/32 of gap roughly) its cool.

for something a little under 3/4 of an inch thick for the over all thickness, it shouldnt change a whole lot through differant heat treated states should it?
-matt
 
Which part is getting banged against? Is it being hit by a thin or sharp object?
Perhaps if it is necessary you could only harden it on the face where it is being hit? Doesnt sound like it needs to be hardened really, but I haven't seen it. Maybe a steel that's quite strong on it's own, say 4140, would be the ticket.

Heat treating a threaded part sounds like asking for trouble to me... unless you got a thread grinder...

We heat treated a 1.5" dia shaft of 4140 in the shop, water quench, it came out .020" bigger.
 
ok that makes sence. basicaly how it works is like so

[]/-/-/-/-[/]

the "[]" represents the "hammer" (a small piece of round stock that gets pushed against a valve to open it" the "/-/-/-" represents a spring and the "cocking rod" that screws into the hammer and is what pulles it back. the[/] is the "dialer" that i am fab'ing. so there is a very small area that migh be struck (its blunt, or pretty blunt, basicaly it shouldnt cut anything and shouldnt be very damaging.

one thing that makes it harder to figure out how strong it needs to be is that hammers for this type of paintball marker are made from a few differant types of materials (brass and steels are the most common).

thanks for the help, i think what im going to end up doing is making the 2 my friend wants and seeing how they work out, if they get dammaged some ill make new ones and get them HT'ed.

thanks again
-matt
 
i think you could use austenitic stainless steel for paintball parts, you dont have to heat treat that. its realatively soft when machining it, just go slow if you dont have advanced equipment. you could probably find pieces cheap at some local scrapyard too.
 
alrigt thanks, do you hapen to play or was that just random machinest thought?

i was able to find some differant rod stock from mcmaster for like 7 bucks a foot (ill be able to do 8 pieces) i think my cost on parts per kit would be liek 3 bucks and i know people would be willing to pay me 10-15 easily for it (seeing as originaly the profesionaly made ones were 25-35 ish).

thanks
-matt
 
it was just a tought. i think most austenitic grades are quite usable for most stuff, well except for knifeblades that is, and you can easily weld them. when making threads try it first on a scrap/leftover piece. you might break the tap, then its stuck in the hole.. you might want to try out different lubricants also (alcohol/different oils/grease/cutting fluids) to see what works best.

i dont know what grades are the best for this application tho, but i think most kinds will do. unless the part have to be very hard.
i´m making some wheels for a grinder with austenitic ss now, i think it works good. nice and shiny :)
 
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