Temp to heat A2 sleeve for press fit?

Terry Keeley

Titanium

Joined

Oct 18, 2005

Location

Toronto, Canada eh!

• Mar 24, 2021

• #1

I have to press a hardened and ground A2 sleeve onto a Thomson shaft with a tight 8-9 tens press fit (15mm bore).

The sleeve was double tempered at 500F for Rc60 hardness, if I heat it to 300F for the press will I screw up the temper? Should I heat it to 500F for the press? Does it matter?

http://www.crucible.com/PDFs/DataSheets2010/dsA2v12010.pdf

 

D

dian

Titanium

Joined

Feb 22, 2010

Location

ch

• Mar 24, 2021

• #2

"Hardened Parts: Heat to 25-50°F (15-25°C) below the
original tempering temperature, hold 2 hours, then cool in
still air"

 

E

Erich

Hot Rolled

Joined

Apr 4, 2017

Location

Poway, CA (from Location field)

• Mar 24, 2021

• #3

Wall thickness on bushing?

 

Terry Keeley

Titanium

Joined

Oct 18, 2005

Location

Toronto, Canada eh!

• Mar 24, 2021

• #4

dian said:

"Hardened Parts: Heat to 25-50°F (15-25°C) below the
original tempering temperature, hold 2 hours, then cool in
still air"

Click to expand...

Where's that from?

Erich said:

Wall thickness on bushing?

Click to expand...

5mm.

 

H

HuFlungDung

Diamond

Joined

Jan 19, 2005

Location

Canada

• Mar 24, 2021

• #5

Don't press it at all, just heat it and slide it on as a shrink fit. Gives a better holding fit. Likely you can't have more than a thou interference or it will crack anyway.

 

W

wesg

Titanium

Joined

Nov 4, 2004

Location

Cedar Park, TX - Boulder Creek/Redwood City, CA

• Mar 24, 2021

• #6

A thin wall like that is going to cool off really fast when it touches the shaft. So you'd need a fair amount of 'clearance', IOW, as hot as you can stand it, and still need to get it on there quick. Heating up to the original tempering won't hurt it at all. It's just gonna turn pretty colors.

 

R

Rickyb

Cast Iron

Joined

Jan 21, 2011

Location

Troy mi

• Mar 24, 2021

• #7

Heating below the original tempering temp doesn’t affect the hardness.

 

EmGo

Diamond

Joined

Apr 14, 2018

Location

in the middle of the edge of the center

• Mar 24, 2021

• #8

Liquid nitrogen and a simple fixture are your friends.

Also, it will want to creep as it comes up to room temp, so if you can keep some pressure on until then, that'll be a good thing.

 

D

dian

Titanium

Joined

Feb 22, 2010

Location

ch

• Mar 25, 2021

• #9

Terry Keeley said:

Where's that from?




thats from the link you posted.

Click to expand...

 

Terry Keeley

Titanium

Joined

Oct 18, 2005

Location

Toronto, Canada eh!

• Mar 26, 2021

• #10

dian said:

thats from the link you posted.

Click to expand...

Oh, that's under "stress relieving for hardened parts".

Anyway, I heated it to 500F (original tempering temp), froze the shaft and it slide right on with close to a thou interference fit.

Finish grinding the O/D now.