Tempering steel

[oleblu72]

Hello could any members enlighten me on the process to harden steel? What I'm trying to do is make a pin for a Case hyd cylinder gland wrench. I ran into a tuff gland a snapped a pin off the tool.

I took a grade 8 allen head bolt and ground it down to the correct size now I'm wondering about the hardness of the bolt campared to the pin I already snapped off.

What is the hardening process for a project like this and maybe I don't even have to do it what do you think? Thanks.

Mark

[grnxrymnky]

hardening metal

depends alot on the type of steel as to the results you'll get, but generally you heat the metal past the critical temp (usually when a magnet no longer attracts it, reddish-orange color) then quench it in anything from water to a real quenching fluid (some knifemakers have their own secret ingredients). this will leave the metal very hard and brittle like a file. next you would put the metal in an oven at about 300 to 400 degrees F for about an hour (again knifemaking timetables and some makers may repeat the process multiple times believing they will achieve more consistent results). the oven heating process will temper the metal--or soften it or draw the brittleness out of it. draw it down enough and you end up with spring steel. that's the way i understand it.........hope it helps

ps...stainless is a whole different story, i don't really know enough about it to even confuse myself, much less anyone else!

[Sonora Iron]

This is how I harden pins:
To harden carbon steel first preheat the area too 1100ºf (dull red) and let free air cool slowly. This removes any stress in the material.
Next reheat the same areas to a dull red then quench in oil until cool. Used motor oil works well as it adds a small amount of acids at the same time. This method also surface hardens the steel.
Reheat the steel area again too 500º then quench in oil until cool. This quench adds temper (return flex) to the steel.

[oleblu72]

Thanks alot guys I'm totaly out of my element with this I mean I knew I had to heat it up and quench it but I really didn't know the right way to do it. I was thinking water makes it hard & brittle and oil makes it soft and air cool somewhere in the middle.

Do you think that this bolt being a grade 8 would be hard enough on its own or does it need to be harder? Thanks again.

Mark

[Sonora Iron]

You gotta give more information! What kind of loads / force? What size bolt?

Here is a bolt chart with shear numbers.

[JonnyTIG]

Generally grade 8 bolts work good for spanner replacement pins without any more screwing around, as long as you dont heat them up too much. I've built large socket spanners using gr. 8 bolts for pins, welded to mild steel cases using gmaw S-6, and held up just fine. Most of the spanners I've built have been used with 3/4 pneumatic impact guns or Hy-Torc systems, upwards of 1000 ft/Lbs.

[oleblu72]

Thanks again for the replys guys. The bolt started out life as a black 7/16 grade 8 allen head bolt but I had to turn the end down to around 5/16. And I will be reefin on it with a 3/4 inch breaker bar using a cheater pipe. If I break it this time about the only thing I can do is weld nuts on the top of the gland which I really don't want to do that.

Mark

[jrscgsr]

I think you would be better off sticking with the grade 8 7/16" bolt than trying to heat quench and temper your bolt trying to make it harder. I think you will be shooting in the dark trying to do it without any experience.

[Daniel]

Thanks again for the replys guys. The bolt started out life as a black 7/16 grade 8 allen head bolt but I had to turn the end down to around 5/16. And I will be reefin on it with a 3/4 inch breaker bar using a cheater pipe. If I break it this time about the only thing I can do is weld nuts on the top of the gland which I really don't want to do that.

Mark

Reefing on a 7/16 grade 8 allen head bolt with a 3/4 inch breaker bar using a cheater pipe. I would try to find the torque for that bolt and use a torque wrench.

[davinci2010]

Reefing on a 7/16 grade 8 allen head bolt with a 3/4 inch breaker bar using a cheater pipe. I would try to find the torque for that bolt and use a torque wrench.

He's not tightening the allen bolt. The bolt is replacing a broken pin on a spanner wrench used to remove the gland on a hydraulic cylinder. He's " reefing" on the spanner wrench itself.

[welder_one]

the threads on the glands will get dirt and grime built up inside the threads. what i have found to work 99 times out of 100 is to take a smaller hammer and tap (hard enough to chip the paint, but not hard enough to make dents) in the cylinder tube all the way around the gland. start adding a little heat and use your gr-8 bolts and take the gland out. if it still doesnt work, then repeat process except this time also hit the face of the gland (be sure to not ding the cylinder rod or it's gonna leak)

i have run across cylinders in older case (yellow) equipment that had set screws to keep the gland from unscrewing itself, and on other equipment, there is a ring of sorts that you have to pull with vise-grips as the gland starts to turn and spin that ring out, then you can unscrew it. if that ring is there and the end broken off, take it to the hydraulic shop and let them chuck it up in a lathe and cut the gland out...

hope i helped

[oleblu72]

the threads on the glands will get dirt and grime built up inside the threads. what i have found to work 99 times out of 100 is to take a smaller hammer and tap (hard enough to chip the paint, but not hard enough to make dents) in the cylinder tube all the way around the gland. start adding a little heat and use your gr-8 bolts and take the gland out. if it still doesnt work, then repeat process except this time also hit the face of the gland (be sure to not ding the cylinder rod or it's gonna leak)

i have run across cylinders in older case (yellow) equipment that had set screws to keep the gland from unscrewing itself, and on other equipment, there is a ring of sorts that you have to pull with vise-grips as the gland starts to turn and spin that ring out, then you can unscrew it. if that ring is there and the end broken off, take it to the hydraulic shop and let them chuck it up in a lathe and cut the gland out...

hope i helped

Thanks to all that has replied appreciate it. Welder One this is one of those tuff glands,this cyl. didn't have a screw in the gland. I've applied heat several times and have been using a brass drift and a hammer on it to break it loose but no luck so far.I think the name of the game here is patience, heat it let it cool beat on it some more and repeat. I hope it doesn't come to that about taking it to a machine shop but I need to get it taken care off,thanks again.

Mark

[srl_welder]

does the gland mount flush with the tube? if not try a chain wrench with a cheater if need be.

when we get a tricky one like this we usually will put a chain wrench and cheater on it while someone else is applying the heat.. be sure to take a rag or two fold them up a couple times and duct tape them over the chrome... unless its chipped, or scratched already and needs rechrome.

we have had cylinders come in that other shops put loctite on the threads... so he had to really heat the tube up and burn it all out. and as Welder One said any dirt will lock it up, and the gland will have to be cut out and a new gland made...hope this helped.

[oleblu72]

does the gland mount flush with the tube? if not try a chain wrench with a cheater if need be.

when we get a tricky one like this we usually will put a chain wrench and cheater on it while someone else is applying the heat.. be sure to take a rag or two fold them up a couple times and duct tape them over the chrome... unless its chipped, or scratched already and needs rechrome.

we have had cylinders come in that other shops put loctite on the threads... so he had to really heat the tube up and burn it all out. and as Welder One said any dirt will lock it up, and the gland will have to be cut out and a new gland made...hope this helped.

Yes the gland flange mounts flouse to the housing the flange is only about a 1/4 inch thick so theres not alot of room for a chain wrench. I rebuilt the other side with no problems and didn't see any signs of any Loctite used.


Mark

[welder_one]

i have taken a pin the size of the barrel eye and welded it to the welding table, set the barrel eye on that pin (so it cant turn) used a small mini-excavator to hold the cylinder down on the table and used a back hoe or forklift on a 48 inch pipe wrench on that lil bit o 1/4 inch gland stickin out.... chewed it up so well, that even if it came out, it would have to be machined anyway....lol....... where ya at, oleblu.... there are several hydraulic shops here, but only 1 that i would trust with MY cylinders... and it might be worth it to ship that cylinder... just a thought...

whats this cylinder off from anyway? i might have a few layin around that would be sold for cheap (hint, hint)