Pre Hardened Sheet Steel?

[WayneB90]

I am having some parts made that attach to a roller chain within a packaging machine,

They are laser cut from 2mm thick steel, with a hole in each end running directly on a hardened steel chain pin with no bushing, (current design)

Just wondering if someone could advise regarding pre-hardened sheet material and its suitable for laser cutting.

I believe the rest of the Tsubaki chain parts are around 45HRC

Thanks.

 

[EdStainless]

Are you planning on reaming the holes? Or doing anything to remove the recast layer?
The problem is that if you use hardenable steel, and Q&T it before cutting then the edges of the cuts will be rough (re-cast) and very hard (basically as-quenched).
You could re-temper then ream the holes to remove rough material.


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P.E. Metallurgy

 

[3DDave]

Seems like waterjet would be the preferred cutting tech for this application.

 

[TugboatEng]

I don't think this component pivots on the pin. The bore doesn't have to be a smooth finish? I would guess the bore only has to be accurate enough to facilitate riveting.

 

[mfgenggear]

What is the diameter of the hole?
And the true position required.
It would be advisable to remachine the hole as stated above.
Magnetic portable drill would also do the job.
Can the hole be laid out by hand.

 

[WayneB90]

Thanks for the feedback.

The previous design was pretty poor in that it was just a deburred laser cut hole pivoting directly on the pin. This was around 5.10mm. This is an RS50 / 5/8th pitch chain

Pin size is 5.09mm according to tsubaki specs but new ones measuring at 5.06

I have had been playing around over the last couple of days and an option which looks like it could work is to have the laser holes cut to 7mm, then ream out to suit a press fit of a bushing taken from a spare inner chain link, This way the plate does not need to be heat treated. Any thoughts?

Thanks

 

[EdStainless]

That sounds like it takes care of a lot of issues.
What strength level do you need in these plates? You might be able to look at a high strength low alloy sheet material.

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P.E. Metallurgy