Metallurgy of fireplace grates

[hackberry jake]

I have went through a few fireplace grates. I'm sure letting the ashes build up around them makes them go bad faster. They get super brittle and can shatter like glass once they have been in there for a while. Is the iron getting impregnated with too much carbon? Or is it oxidizing from the inside? Or is it just getting brittle from too many heat/cool cycles? If it's carbon, can you make high carbon steel in a wood stove? I think I'll try making my own pretty soon. Any ideas on what to make it out of for longevity? I usually just use old cast iron grill grates from a BBQ grill.

[gspren]

I think it's more likely that you burn the carbon out after enough cycles. At our hunting camp we only got a few years out of cast iron so we made one with 2 pieces of 4" I-beams to space it up and a bunch of 1" x 2" pieces of hot rolled for the main grate and used the same to put a piece a few inches higher front and back. It's now about 20 years old and some of the middle pieces are nearly burnt through but still usable and easy to replace a couple bars where needed. This is used heavy a few weeks a year and we are often guilty of not cleaning the ashes away until spring/summer. I could lift it then in my 40s but it might have gotten a bit too heavy for my 67 Y.O. back, things tend to have gotten heavier, couldn't be I've gotten weaker.

[Klunker]

I had a buddy make mine from 1/2 thk  304 ss.
Its lasted over a year with no signs of deterioration.

[bodagocreek2]

My grates in my wood boiler I made out of 1 inch re-rod. Over 30 years and really just like new. My wood burning fireplace I made the grate out of 1/2 inch re-rod, still like new, about the same age. Re-rod is fairly cheap and easy to weld and work with.