Do you heat your bearings b4 installation?

[Bolster]

Do you heat your bearings before you install them? If so, do you use one of those $400 bearing heaters, or do you just pop them in a toaster oven on low?

I have read that 250 is the maximum for a bearing preheat. What's your experience?

 

[A_Pmech]

Depends on the application. Heating a bearing so that it expands isn't very helpful for an internal bore. In that case, the part should be heated and the bearing cooled.

For slipping over shafts, I normally put the shaft in the deep freeze and heat the bearing to 100-150F with a hair dryer. 250F isn't too far off annealing temperature and will break down the grease packing in a shielded or sealed bearing to oil and soap.

150F of differential is almost enough to relieve a standard fit. That should be all that's necessary to ease the fit. Work fast!

 

[G1K]

More often than not I have to install a bearing in a cavity and heat the cavity and freeze the bearing.

R

 

[Swampy]

Another great method I have used for years is a crock pot. Find one at a junk sale or thrift store for a few bucks and add some hyd or other oil. On medium mine heats to about 200F, perfect.

 

[A_Pmech]

Another great method I have used for years is a crock pot. Find one at a junk sale or thrift store for a few bucks and add some hyd or other oil. On medium mine heats to about 200F, perfect.

This!





One of the problems you run with a toaster is temperature control. Toasters have notoriously inaccurate temperature controls which permit wild swings in actual temperature. Also, there's no way to separate the radiated heat from the convective heat. Thus, while the air temperature in the oven could still be "cold" to the convective heat-sensing bi-metallic temperature controller, your part could be at 400F due to radiated heat (infared).

That's one of the big reasons why you should pre-heat an electric oven before adding a cake, for example.

Annealing your new bearings isn't a key to longevity.

 

[Chris Adams]

Last few times I used my heat gun. Works pretty good for getting them off also.

Using the laser thermometer I can monitor the heat and keep them pretty even, rotating the bearing while I blast it.

Helps a lot.

Have frozen a few in the freezer over night on occasion for those internal installations.

 

[35mastr]

Never really had the need to heat them up. Just use the press.

 

[isr2kba]

This!





One of the problems you run with a toaster is temperature control. Toasters have notoriously inaccurate temperature controls which permit wild swings in actual temperature. Also, there's no way to separate the radiated heat from the convective heat. Thus, while the air temperature in the oven could still be "cold" to the convective heat-sensing bi-metallic temperature controller, your part could be at 400F due to radiated heat (infared).

That's one of the big reasons why you should pre-heat an electric oven before adding a cake, for example.

Annealing your new bearings isn't a key to longevity.

I thought you needed 1000 degrees Fahrenheit before you were anywhere near annealing steal???? I used to work at a metal processor and the lowest setting on the annealing oven was 1100 F and the highest was like 1900 F. IIRC, the settings were varied depending on the composition of the steel.

 

[Kevin54]

I thought you needed 1000 degrees Fahrenheit before you were anywhere near annealing steal???? I used to work at a metal processor and the lowest setting on the annealing oven was 1100 F and the highest was like 1900 F. IIRC, the settings were varied depending on the composition of the steel.

I know that when I heat treat tool steel (O-1) I heat treat it at 1475 and anneal it at around 400-450

 

[The Rusty Gear]

I thought you needed 1000 degrees Fahrenheit before you were anywhere near annealing steal???? I used to work at a metal processor and the lowest setting on the annealing oven was 1100 F and the highest was like 1900 F. IIRC, the settings were varied depending on the composition of the steel.

You don't need to anneal a steel to change it's properties.

It only takes a few hundred degrees to ruin a temper (over-aging, temper embritlement, partial annealing etc etc) -- It depends on the steel but *usually* up to 400F is OK for short periods.

 

[Elroy]

I thought you needed 1000 degrees Fahrenheit before you were anywhere near annealing steal????

Exactly.

A typical bearing alloy is AISI 52100. Reference this chart:

http://www.crucibleservice.com/eselector/prodbyapp/carbon/52100.html

Notice the annealing temperature is 1100-1300 F. You're not going to get that in your toaster oven.

The point about degrading the lubricant and seal materials is valid. So it really depends on the construction of the bearing. If it's your typical all steel tapered roller bearing have at it with the home oven and have no worry. Also the larger the bearing the more it grows with temperature. Then again a small bearing will have a small press.

For the home installations, Elroy has found that cooling the parts is typically much easier than heating the parts and just as effective. Especially when you combine both techniques as you're after "delta T"

The statement about annealing the bearing with a toaster oven is bull. Hell you would be lucky to even temper it as that would take hours to accomplish. For a bearing assembly using heat, have no fear using a home oven as they are not going to get hot enough.

Look at the wire trays. They last fine and are not near as alloyed as a bearing material.

Kel, What are trying do ??

 

[The Rusty Gear]

Exactly.

A typical bearing alloy is AISI 52100. Reference this chart:

http://www.crucibleservice.com/eselector/prodbyapp/carbon/52100.html

Notice the annealing temperature is 1100-1300 F. You're not going to get that in your toaster oven.

The point about degrading the lubricant and seal materials is valid. So it really depends on the construction of the bearing. If it's your typical all steel tapered roller bearing have at it with the home oven and have no worry. Also the larger the bearing the more it grows with temperature. Then again a small bearing will have a small press.

For the home installations, Elroy has found that cooling the parts is typically much easier than heating the parts and just as effective. Especially when you combine both techniques as you're after "delta T"

The statement about annealing the bearing with a toaster oven is bull. Hell you would be lucky to even temper it as that would take hours to accomplish. For a bearing assembly using heat, have no fear using a home oven as they are not going to get hot enough.

Look at the wire trays. They last fine and are not near as alloyed as a bearing material.

Kel, What are trying do ??

Good information Elroy, but based on the data on the page you provided, you can temper the bearing material above 300F if it is in the quench and tempered condition. You're *probably* OK, but DON'T quench the material in water afterwards. Let it air cool.

Wire trays are not tempered steel so it is not a fair comparison You could take them up to 1000 degrees and they won't change.

 

[Bustawrench]

Another great method I have used for years is a crock pot. Find one at a junk sale or thrift store for a few bucks and add some hyd or other oil. On medium mine heats to about 200F, perfect.

Goerge Foreman Grill works in a pinch...........................











Hope my wife don't see this.

 

[A_Pmech]

I thought you needed 1000 degrees Fahrenheit before you were anywhere near annealing steal???? I used to work at a metal processor and the lowest setting on the annealing oven was 1100 F and the highest was like 1900 F. IIRC, the settings were varied depending on the composition of the steel.

Ooops! My mistake... I meant to say "temper", but I had annealing on my mind.

Yes, you're right. For a full anneal, anywhere from 1,000F up.

However, tempering heat is 300-500F which was my point. You can blast though the tempering range with a toaster oven with no problems at all. Again, not due to the convective heat, but radiation off the exposed heating elements.

 

[Thedroid]

I try to if possible. We have an old style cone shaped bearing heater, and also one of the fancy SKF induction heaters. If the bearing is going into a part, I'll heat it up a little with the torch.

 

[Thedroid]

We use this one. Heats bearings with a 2" bore in about 2 minutes

 

[mdoolittle]

I prefer to freeze the bearing, race, or shaft overnight rather than play the heat game.

 

[Underdog]

What about the BFH approach.

 

[ZRX61]

Never really had the need to heat them up. Just use the press.

This

 

[rsanter]

heat the case a little) or freeze the shaft and use a press.

I use a BBQ to head a ring gear to install on a flywheel

also use the BBQ to preheat and post cool cast iron for welding

bob

 

[Thedroid]

I've used the press many a time, but heating is so much easier.

 

[caper]

heat the case a little) or freeze the shaft and use a press.

I use a BBQ to head a ring gear to install on a flywheel

also use the BBQ to preheat and post cool cast iron for welding

bob

That's one I haven't tried yet,nice thinking.Although I have used a woodstove from time to time.Lay the bearing,hub or ring gear on top of the woodstove and monitor it with the laser temp gun.Usually leave it till just over 200 degrees.Preheat cast on it and throw the part inside to cool as the fire goes out.