3D wooden manequin, but the joint screws just look kooky lol

Hi Alls
Im currently working my way through the 3D Character Creation and Animation course.
Im upto the wooden manequin stage and all was lookin g good UNTIL I applied the material to the joint screws and made them look metalic.
Well the screws slots just dont look right.
Any Suggestions ??

You might want to check the normals are correct. Go into edit mode select the whole mesh and press shift + N to recalculate. Also if you have smooth shading enabled you can go to the normals and select under the “object data properties” and select smooth under the normals dropdown.

Cheers for that , I decided to remake the parts ad this time they turned out as expected.
I did notice that on the original , when I turned on the Display Normals -Face there were some strange lines going out at 30degrees . BUT On the remake they wernt present. So Im guessing I messed up the initial contruction lol