Rulers - Haven't needed to do this, but I saw a demo where they put a much used ruler vertically on a granite countertop and you could see where it was bowed in the middle from tiny slivers being cut from it. I periodically check mine to make sure the edge isn't damaged.
Cutting Mats - 15 years
Rotary cutters - 20 years
Rotary blades - bought a bunch so as soon as they skip or I have to press really hard.
Pins - every 6 -12 months i go thru & discard bent or dull ones. For some reason, I pick up a bent pin & put it back in the pincushion instead of throwing it out.
Needles - when it gets dull
Chairs - never
Sewing Machines - going on 20 and 15 years.
Scissors - never
Seam Rippers - haven't replaced any, but do have several
Die Cutter cutting pad - I have an Accuquilt Studio and when I can't stand cutting the excess connecting threads, I change the pad.