This is a great tool for bead and wire artists. This two piece 6" mandrel set, made of stainless steel with a non-slip PVC handle, will give the user consistent size loops time after time. Nicely rounded and extremely smooth so wire will not be scratched. A Jewelry Tools Best Seller. The small mandrel's diameters include 1.50, 2.50, 3.50, 4.50 and 5.0mm. The larger mandrel's diameters include 6.0, 7.0, 8.0, 9.0 and 10.0mm.