The screw threads of the regular Duplo models are located in the heel area and fixated in the synthetic material. The small studs improve the anti-skid-protection on slippery grounds.
These studs are not designed for the use in the thread inserts of Duplo horseshoes with ring-shaped metal inlay.
6mm/M8: square stud
4mm/M8, M10, M12: hexagonal stud
Good to Know:
When you use regular Duplo models, we do not recommend to constantly change the studs or to use higher studs. For these purposes, the use of Duplo models with ring-shaped metal inlay is more appropriate.
If you are not planning to remove the studs, you can add a drip of screw retention or superglue to the screw threads before screwing the studs into the horseshoe.