Crosshead Guide Material

This forum is dedicated to the Live Steam Hobbyist Community.

Moderators: Harold_V, WJH, cbrew

rhbroehl
Posts: 17
Joined: Sun Nov 25, 2018 7:58 pm
Location: Johnstown, Ohio

Crosshead Guide Material

Post by rhbroehl » Tue Apr 14, 2020 11:40 am

Hi,

I have to build 4 crosshead guides for me LE 0-4-0. They are 3/8 x 1/2 and I wondering if I could use key stock material for the guides. The material has fairly tight tolerances so I would think it would work.

Comments? Other ideas?

Thanks

Rob

Mike Walsh
Posts: 714
Joined: Sun May 06, 2007 10:14 pm
Location: St. Louis, MO

Re: Crosshead Guide Material

Post by Mike Walsh » Tue Apr 14, 2020 1:03 pm

Probably work ok.

For the Allen cylinders that I'm machining at present, I picked up some 4140 prehardened material. Already ground to size. I think that'll hold up OK.

If you're interested in that route, check out McMaster #8892K47. I haven't tried machining it yet but hopefully will be able to in the next few months. Shouldnt be too bad - cut to length, drill a few holes here and there..

hoppercar
Posts: 332
Joined: Sun Jul 22, 2018 4:09 pm

Re: Crosshead Guide Material

Post by hoppercar » Tue Apr 14, 2020 3:32 pm

I also used 4140 prehard....it has a rockwell around 35 to 38 I believe...which is still plenty soft to be machined.....but has better wearing characteristics than just plain 1018 c.r.s.

User avatar
ALCOSTEAM
Posts: 673
Joined: Tue Feb 04, 2003 9:20 am
Location: illinois

Re: Crosshead Guide Material

Post by ALCOSTEAM » Tue Apr 14, 2020 7:06 pm

Actually been working on a set of guides for some wagner cylinders and used 4140 crs. I bought some cobalt end mills but would go carbide next time..
Another thing to remember about 4140 crs is it will pull as you machine it.. take small cuts equally on opposing sides to keep the pull equal.

User avatar
Benjamin Maggi
Posts: 1304
Joined: Wed Apr 25, 2007 10:38 pm
Location: Albany, NY

Re: Crosshead Guide Material

Post by Benjamin Maggi » Wed Apr 15, 2020 9:28 am

I used keystock on my engine's crossheads. A word of warning: I purchased my steel through Metal Supermarket and they shipped me keystock that looked like it had been sheared from a larger piece. It is hard to describe, but it wasn't perfectly square and such that you would expect from Keystock. They then replaced it with the right stuff when I went back.
"One cannot learn to swim without getting his feet wet." - Benjamin Maggi
- Building: 7.25" gauge "Sweet Pea" named "Catherine"

BClemens
Posts: 424
Joined: Sat Oct 08, 2016 10:04 pm

Re: Crosshead Guide Material

Post by BClemens » Wed Apr 15, 2020 10:29 am

I've noticed that some of the 'big box' stores that sell lengths of steel of various types and sizes are selling 'angle' and 'channel' that are nothing more than sheared sheet metal braked to an angle or channel. Finding the small hot rolled angle and channel seems to be getting rare.
bc

tetramachine
Posts: 182
Joined: Sun Mar 19, 2006 6:27 pm
Location: NJ
Contact:

Re: Crosshead Guide Material

Post by tetramachine » Wed Apr 15, 2020 11:02 am

4140 PH is closer to 25-28 HRC in hardness. Key stock may well be on size, but is usually made of junk steel. If you want On Size material, look at any of the tool steels. they are all sold in annealed condition, and can be on size to a few thou. Look at the online sites to find you needs. Sites like OnLine Metals, Yarde Metals Drop Zone was great deals on drops (Cutoffs), MSC and Mcmaster. Hardware store or Big Box store I would not touch their metal.
My wheels don't slow me down

BClemens
Posts: 424
Joined: Sat Oct 08, 2016 10:04 pm

Re: Crosshead Guide Material

Post by BClemens » Wed Apr 15, 2020 2:55 pm

If you don't need a piece of structural steel with certs, and you have the ability to look at it and make a judgement about what it is (mill carbon coated for example) and judging the method of forming (hot rolled or braked), you can probably purchase an adequate piece of angle iron from a big box store. That is not to say that the purchase is not a rip-off considering the price at the big box store. If a piece of 'key stock' was ordered and had the tell tail indication of being sheared we would probably stay away from that supplier too (although referenced made it right). Key stock for crossheads is probably not a wise choice because it is very low carbon and is a basic soft steel intended to shear in situ. Not meaning sheared to size before you use it - not very likely anyhow. It is nicely put to call it junk steel - we always called it crap steel and doesn't even weld well. Off the peach crate.. just saying...
bc

Something else about soft steel, brass or even zinc. It will 'charge' or become embedded with material particles (dirt grit - or - diamond dust) that will cut another harder piece of material (steel). Once embedded it becomes the 'wear' part and will cut the 'worn' part to over tolerance. Best the other way around for crosshead guides rather than crossheads. Crossheads are (on full sized) made to adjust to make up for wear. Make the crosshead guides out of hardened steel or at least hard surfaced steel that will not embed.

User avatar
Greg_Lewis
Posts: 1984
Joined: Wed Jan 15, 2003 2:44 pm
Location: Fresno, CA

Re: Crosshead Guide Material

Post by Greg_Lewis » Wed Apr 15, 2020 10:08 pm

BClemens wrote:
Wed Apr 15, 2020 2:55 pm
...

Something else about soft steel, brass or even zinc. It will 'charge' or become embedded with material particles (dirt grit - or - diamond dust) that will cut another harder piece of material (steel). Once embedded it becomes the 'wear' part and will cut the 'worn' part to over tolerance. Best the other way around for crosshead guides rather than crossheads. Crossheads are (on full sized) made to adjust to make up for wear. Make the crosshead guides out of hardened steel or at least hard surfaced steel that will not embed.
This ^ ^ ^

I made my guides from common CRS and after one run around a track I found them to be scored even though they were well lubricated. The crosshead shoes were 660 bearing bronze.
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 30 years of turning perfectly good metal into bits of useless scrap.

User avatar
Lovesthedrive
Posts: 248
Joined: Sun Dec 18, 2011 10:52 pm
Location: Downeast Maine

Re: Crosshead Guide Material

Post by Lovesthedrive » Thu Apr 16, 2020 1:50 am

So all this chatter of why Key steel might be bad. Yet no suggestions of what should be used as an alternative? Seems like too many armchair warriors here.
1952 John Deere model 60

Wanted: Half size steam tractor. Will trade land in Maine

Harold_V
Posts: 18420
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Crosshead Guide Material

Post by Harold_V » Thu Apr 16, 2020 1:56 am

Perhaps a reread would help. Heat treated chrome moly was mentioned (4140) and provides an excellent wear surface, plus you can achieve the flatness and squareness desired.
I fully agree with not using keystock. It isn't hardened, and may or may not be flat and or square. Mild steel is notorious for galling. Not a great bearing surface.

H
Wise people talk because they have something to say. Fools talk because they have to say something.

User avatar
PeterCraymer
Posts: 201
Joined: Thu Oct 02, 2003 6:57 am
Location: Maysville, Ga.

Re: Crosshead Guide Material

Post by PeterCraymer » Thu Apr 16, 2020 8:24 am

Often times keystock is plated as well, so that is another thing to look out for. I used 1/4 x 1/2" HRS for my 10-Wheeler and used the stock Allen Models cast bronze crossheads and have no problems after 7 years of running. Sure was nice not having to do much machining on those parts!

Post Reply