Quick Answer

Most trapezoid plates use a pin-and-spacer system: knock out the retaining pins, remove the worn segments and spacers, slide new segments into the same slots, and re-seat the pins so the segment faces sit flush. Keep each plate's segments matched in height so the plate runs flat and grinds evenly.

Know Your Plate System

Trapezoid tooling, like the diamond trapezoid grinding disc, usually holds segments with pins that pass through the segment holes, locked by spacers or washers. Some plates use screws instead. Check the plate type before buying replacements: segment size, pin diameter, and segment count must match the plate.

Removing the Worn Segments

Lay the plate face down on a clean surface. Remove the retaining pins with a pin punch and hammer, tapping gently so you do not bend them. Slide the worn segments and any spacers off the plate. Clean the slots and check the plate body for cracks or bent pin channels before fitting new segments; a damaged plate is not worth re-segmenting.

Fitting the New Segments

Slide the new segments into the slots with the diamond face pointing outward, adding the same spacers the old segments used so every segment sits at the same height. Insert the pins and tap them home until they are flush. Give each segment a light tap: they should be firm, not loose. Re-check that all segment faces are level; a single proud segment will make the plate wobble and carve grooves.

Run-In and Checks

Run the re-segmented plate for a few minutes on a clean scrap of concrete before the real job, so the new segments bed in evenly. Stop and re-tighten or re-tap any pin that has worked loose. Then continue with normal grinding. Keep spare pins and spacers on the truck; they are the parts that get lost on site.

Frequently Asked Questions

Q: How do I know when trapezoid segments need replacing?

A> Replace when segments are worn below about half height, when they stop cutting and dressing does not help, or when any segment cracks. Run a full set at once for even wear.

Q: Can I mix new and old segments on one plate?

A: No. Mixed heights make the plate run unevenly. Replace the full set on a plate at the same time.

Q: Why did my pin not go back in?

A> A bent pin or a slot full of debris. Check the pin for bends, clean the channel, and try a fresh pin rather than forcing it.

Conclusion

Re-segmenting a trapezoid plate takes minutes once you know the pin system: remove, clean, fit matched segments, re-pin, and bed them in. Keep the plate flat and the segments matched and your tooling keeps grinding like new.